WO2010019633A1 - Device and method for removing solids from solution - Google Patents

Abstract

The concentration of solids dissolved or suspended in a liquid is reduced when a reagent and kinetic energy are added to the solution. Kinetc energy can be added by turbulent flow in a recirculation device. Separation of solids from the solution is particularly promoted when the recirculated liquid stream is directed into the region of intersection of intersecting or colliding vortices within a vessel containing the subject liquid. Such intersecting vortices can be established by withdrawing a liquid stream through one or more appropriately positioned ports in the vessel. Solutions can be industrial, medical, agricultural and municipal wastes and naturally occurring waters in need of cleaning.

Description

DEVICE AND METHOD FOR REMOVING SOLIDS FROM SOLUTION

Applicant claims priority of United States Serial Number 61/188,704, filed August 11, 2008.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT Not Applicable

REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISC APPENDIX Not Applicable

BACKGROUND OF THE INVENTION Field of the Invention

This invention relates generally to changing the concentration of solids in solutions and, more particularly, to reducing the concentration of solids in solutions exemplified by industrial, municipal, medical and agricultural wastes by a process that comprises the addition of an oxidizer and kinetic energy to the solution.

Background Improved methods and devices for reducing the concentration of solids in solutions are of great interest in many industries where manufacturing by-products and waste materials often take the form of solutions that carry dissolved or suspended solids. Such improved devices and methods also are of great interest to municipal wastewater treatment plants where raw sewage comprises mainly organic solids suspended or dissolved in an aqueous solution and where treatment of the sewage normally produces an aqueous sludge of organic solids.

Treatment of residential, industrial, shipboard, agricultural and infectious waste is of great importance for both public health and environmental management. Such wastes have long been treated by the application of microbial agents, oxidative chemicals or both to reduce their threat to the public health or to the environment. Such treatments have been successful and have gained wide acceptance. However, known treatments normally require considerable time and space in order to be effective. For example, residential wastewater usually takes from days to weeks to undergo treatment using conventional, biologically based techniques and generates large quantities of organic solids, sludge, that must be further treated prior to ultimate disposal or reuse. The sludge handling systems within conventional municipal wastewater treatment plants take up much land, use significant manpower and other resources to operate and maintain, and often are a source of many of the objectionable odors in a wastewater facility. The typical cost of sludge management is 30 to 60% of the operating cost of a municipal wastewater treatment system. The residual sludge product, even after this expensive processing, must be disposed of in a landfill or land applied. There is a need for a device and method for treating municipal wastewater that produces less sludge to manage, is not esthetically objectionable, requires less space, and results in less residual material for disposal.

Sludge that is produced in a typical municipal wastewater treatment plant can be handled in various ways within the plant to minimize the cost of ultimate sludge disposal. For example, it can be pumped as an aqueous slurry to a drying bed or to a belt press for liquid reduction or dewatering. In a drying bed, water in the sludge separates and drains back into the plant, usually through sand filters in the floor of the drying bed. On a belt press water is squeezed from sludge by applying pressure. The efficiency of either process can be negatively affected by sludge that is difficult to dewater. For example, characteristics like small particles or colloidal suspensions clog filters in drying beds or clog belt press filter media. There is a need for a treated sludge that dewaters rapidly and does not clog filter media.

There is a need in the wastewater treatment industry for a versatile treatment system that can be adapted without major modification to reduce the solid content in raw sewage and in both aerobic and anaerobic sludges.

Current efforts to treat wastewater treatment plant effluent so that it can be beneficially reused in non-potable and potable applications are complex and expensive. Wastewater components such as colloidal suspensions make the treatment more difficult and expensive due to filter clogging. The production of wastewater treatment plant effluent with less material held in suspension has been an unmet need.

An improved system for reducing fats, oils and greases (FOG) in wastewater influent or in sludge also is needed. It is believed that water will drain more quickly from sludge in drying beds and will move more easily through sand filters if the sludge slurry contains fewer untreated or partially treated FOG's. Likewise, it is believed water can be pressed more easily from a sludge slurry by a belt press when the sludge contains fewer FOG's.

Many existing wastewater treatment plants use microbes to consume solids in wastewater in a biologically based aerobic process. The oxygen level in the wastewater must be at an optimum level for the microbes to complete the treatment process, requiring installation and operation of air blowers to aerate the wastewater. Air blowers require significant electric power on a constant basis. A less expensive method for adding oxygen to wastewater in aerobic treatment systems would be welcome.

There is a need in the wastewater treatment industry for a versatile treatment system that can be adapted without major modification to reduce the solid content in raw sewage and in both aerobic and anaerobic sludges.

The time and space requirements of typical wastewater treatment facilities make them substantially useless in confined areas, such as on ships and in submarines. Seagoing vessels are sometimes required for environmental or military reasons to retain waste (black water and gray water) in storage during a voyage for subsequent offloading and treatment at dockside. Retaining waste in storage onboard ship is a space and sanitation problem. Disposal of bilge water is also a major problem for the shipping industry. Disposal of bilge water is the subject of many regulations designed to protect ports from pollution and often results in fines for shippers. There is a need for a small "footprint" onboard system for effectively dealing with black water, gray water and bilge water in seagoing vessels.

The size requirement of municipal waste treatment plants is also a problem in crowded urban areas. There is a need for a device that would eliminate the land intensive portions of the sludge handling systems, such as sedimentation and sludge ponds, freeing the space they normally require for other purposes. The disposal of infectious wastes is also a worldwide problem. Present devices for the treatment of infectious wastes usually require high pressure and/or heat, making safe infectious waste disposal prohibitively expensive in many areas of the world. Hospital wastes, include bandages, sharps, blood, tissue and the like. Renal treatment centers need to dispose of dialysis product, filters, membranes, needles, tissue, fluids and other such waste in a safe and effective manner. Morticians must dispose of blood, embalming fluid and tissue, all of which may contain dangerous microbes. The safe disposal of infectious wastes is a problem for the industries that produce it. An effective, inexpensive and relatively small device to render infectious waste harmless would solve these problems. A side effect of increased use of factory farms in recent years is large amounts of foul smelling animal waste, especially from hogs, that must be contained and disposed. Animal waste from such farms and from feed lots for cattle often is accumulated in lagoons while awaiting disposal or treatment. Odors from the lagoons and from the farms themselves lower property values in surrounding areas, and disposing of the accumulated material is expensive for the farm and feedlot operators. Wastewater from these lagoons often leaches into the underlying earth causing groundwater problems. There is a need for an improved system for disposing of animal waste from livestock operations whereby odor, environmental effects, and expenses are reduced.

Disposal of manufacturing wastes by industry also is a problem. NonΗmiting examples of industries that produce such problematic wastes are the food industry and the petroleum industry, both of which produce waste that requires treatment. Some municipalities prohibit the discharging of industrial wastewater into local sewage systems unless the material has been pre -treated. This is often a major expense for industry, and many industries have been unable to consistently meet municipal or state pretreatment requirements , resulting in fines and negatively impacting public image. Improperly pretreated industrial wastewaters cause operational problems at municipal wastewater treatment facilities, including plant upsets, permit problems, and additional expense. The problem of effective on-site treatment of industrial waste could be solved by an effective, inexpensive and relatively small device that brings industrial waste within municipal sewage guidelines.

The need for treatment of water of unknown quality to assure its potability is also of great importance, especially in military operations and in civil emergencies. It is often logistically impossible to boil or otherwise to sterilize large quantities of water on-site in military operations. The transportation of potable water to military operations is expensive, difficult, and dangerous, if not impossible. Likewise, floods, storms, earthquakes or digging accidents can cause ruptures in municipal water mains, resulting in the need to treat large quantities of water that might be contaminated. Heavy rains also can overwhelm wastewater treatment in cities having combined sanitary and storm sewers, resulting in the discharge of untreated sewage into rivers and streams. Such discharges are called combined sewer overflows (CSO's). New regulations discouraging or banning CSO's have caused many municipalities to undertake financially burdensome upgrading of waste treatment systems, sometimes including massive retention facilities to hold untreated wastewater from storm sewers until it can be treated. There is a need for a much less expensive system for avoiding CSO's and for quickly treating storm sewer surges.

Because storms and floods that usually cause CSO's are relatively unpredictable and often arise quickly there is a need for systems to stand-by at CSO outfalls and to operate automatically or to be operated remotely when needed to deal with CSO's that arise suddenly. There also is a need for systems and processes that are able to treat CSO's sufficiently that the system effluent could be returned to streams, rivers or lakes without the introduction of materials that would be harmful to the environment, fish or other wildlife.

The military and civilian need for a portable means to treat water of unknown or damaged quality is significant. Significant military logistics problems will be solved by providing a relatively small device that can remove organic pathogens from water available in rivers, lakes and wells or from compromised water systems in a relatively short period of time. A device capable of converting sewage to potable water also would be useful on ships and submarines and in other situations where both space and potable water are scarce, such as in spacecraft. There also is a need for treatment systems that are sufficiently small and compact to be transported to locations where they are needed.

Stricter government regulations in many areas now prohibit the use of septic tanks in new housing additions, effectively requiring expensive connections to remote wastewater treatment plants. In other areas, soil is unsuitable for septic systems and resulting in asimilar need for builders to connect new housing to existing municipal wastewater treatment plants by expensive pipelines. There is a need for a small, odor free and inexpensive system for treating sewage from a house or a housing development to a sufficiently high quality that would allow beneficial reuse of the effluent for irrigation of green space or farmland The present invention relates to critical features not shown or suggested in US Patent

5,087,420 issued on Feb. 11, 1992 to the inventor of the present invention. For example, the '420 patent does not show or suggest the use of vortices having colliding margins and discloses as a preferred embodiment a structure in which such vortices could not occur. The structural arrangement of the device shown in the '420 patent, although somewhat useful, tended to result in a single standing wall vortex extending in toilet bowl fashion upward from the centrally located drain. The standing wall vortex acted as a centrifuge. Suspended solids were not maintained in solution but were separated by centrifugal forces to the sides of the tank where they fell to the bottom and accumulated without being treated. Reduction of CBOD (Carbonaceous Biological Oxygen Demand) levels in the treated wastewater was not satisfactorily quick or complete. Discoveries made while attempting to overcome these disadvantages of the device described in the '420 patent led to the present invention.

BRIEF SUMMARY OF THE INVENTION

It is an object of this invention to overcome the problems of the prior art. It is also an object of this invention to provide a relatively small device for treating municipal, industrial, pharmaceutical, animal and infectious waste rapidly and effectively.

It is still another object of this invention to change the concentration of solids in a solution quickly using a device having a relatively small footprint. It is also an object of this invention to reduce the concentration of organic solids in an aqueous solution thereof without the creation of dangerous, toxic or harmful byproducts.

It is another object of this invention to add oxygen content to wastewater treatment plants while minimizing the use of energy-consuming fans or blowers. It is still another object of this invention to make available a system capable of reducing the level of solids in solutions comprising aerobic sludge and anaerobic sludge from wastewater treatment plants, storm sewer liquids (including CSO's) and raw sewage without the creation of toxic by-products or lasting colloidal suspensions.

It is a further object of this invention to overcome the problems created by the need to store sewage and other waste onboard ships at sea and on submarines by providing a relatively small device for treating such sewage and waste onboard. Likewise, it is an object of this invention to provide a device for treating bilge water and wastewater in ships.

It is also an object of the present invention to provide for the safe and rapid treatment of waste from restaurants and infectious wastes from sites such as mortuaries, hospitals, dialysis treatment centers, blood banks and nursing homes to remove pathogens and to make infectious wastes suitable for introduction into municipal waste treatment systems.

It is yet another object of this invention to avoid the need for the extensive leaching beds required by domestic septic systems and to provide suitable self-contained sewage disposal systems for use by housing additions, mobile home parks, shopping malls, highway rest stops, parks and the like that are remote from municipal wastewater treatment plants.

It is still another object of this invention to reduce or eliminate organic solids in animal waste from feed lots, factory farms and other concentrated animal production facilities and to eliminate associated odors.

It is also an object of this invention to provide a portable device for treatment of available water of unknown quality to remove any harmful materials and to provide a device to quickly and effectively purify domestic water when water supplies are compromised.

It is a further object of this invention to provide a device and method for converting sewage to potable water or to water that can be used in landscaping systems or in fire protection systems. It is still another object of this invention to treat combined sewer overflows substantially in real time and, optionally, automatically or by remote control.

These and other objects are accomplished in the present invention by adding to a solution in a substantially closed container both a reagent and an effective level of kinetic energy whereby the concentration of solids in the solution is changed.

In another aspect of the invention, these and other objects are achieved by a device comprising a substantially closed container suitable for holding a quantity of solution to be treated, at least one kinetic energy subsystem associated with the container for adding an effective level of kinetic energy to the solution and at least one reagent subsystem associated with the at least one kinetic energy subsystem or associated with the container or associated with them both for adding reagent to the solution.

For convenience, use of the present invention will be described mainly in terms of treating municipal wastewater, although the invention is not limited to municipal wastewater treatment. Wastewater is broadly used herein to describe a pumpable liquid solvent containing suspended or dissolved solids. Usually, the solvent includes water in amounts sufficient that the solution can be described as an aqueous solvent. The solids carried by the solution may be any materials that are capable of being dissolved or suspended in the solution. As described more specifically in the Examples, below, the solids are usually organic in nature. Normally it will be an objective to change the concentration of solids in the solution by reducing or eliminating them.

Generally speaking, a solution is a candidate for treatment by the present invention at any concentration of solids that does not prevent the addition of kinetic energy and a reagent in amounts sufficient to accomplish reduction of the solids. When kinetic energy is added to a solution of municipal wastewater by turbulent flow, as described below, the solution may contain any level of solids that still allows relatively rapid pumping through a conduit system, although quicker results are achieved with lower concentrations of solids. A thick solution may be diluted either before or during processing to achieve a concentration that is more efficiently treated. In a wastewater treatment setting, the concentration of solids in the influent is commonly referred to as the "strength" of the wastewater. The wastewater strength in raw sewage is relatively low and typically ranges from about 350 to about 1,200 ppm. The strength of sludge is relatively high and usually ranges from 0.5% to 6%. The invention has been demonstrated to reduce the solids concentration in raw sewage, in sludge produced by wastewater treatment plants and in industrial waste produced by food processing plants, by a steel plant and by a petroleum refinery. Best results were obtained when the level of solids was adjusted to a concentration of from about 1% to about 2.5% by weight. Petroleum wastes and byproducts sometimes require physical manipulation and the application of a surfactant before optimal treatment by the present invention.

The invention has been demonstrated to work well in treating solutions carrying a wide variety of dissolved or suspended materials. For example, the inventive method and system have been used to treat solutions containing restaurant cooking grease, shredded restaurant trash, manure from hog farms, embalming waste, by-products from ketchup production, dialysis lab waste, pickle liquor from steel plants and material collected from septic tanks as well as raw sewage and sludge from wastewater treatment plants. A variety of means can be used to add an effective level of kinetic energy to a solution.

Kinetic energy could be added by ultrasonic devices or by the use of cavitation technologies such as sonoluminescence, for example. The inventor has achieved excellent results adding kinetic energy by using turbulent flow resulting from a designed recirculation pathway for the solution to be treated. When the solution is recirculated in a container having a rectangular cross section, for example, the drain in the bottom of the container is offset from the center, causing two vortices in the solution. The first vortex appears to be centered around the offset drain while the second or harmonic vortex appears to be defined by the volume and shape of the container. A portion of the walls of the two vortices intersect, creating turbulence in the area of collision. Dramatically improved reduction of solids in embalming waste was observed during the operation of this device.

In another embodiment turbulent flow was achieved by rapid recirculation of solution contained in a cylindrical tank having its cylindrical axis parallel to the ground using a centrifugal electric pump system to withdraw solution from the tank through ports in its bottom, resulting in vortices having intersecting walls in the solution with each vortex centered on a port. Tanks with two and three ports have been used with good results. Both sub'surface vortices and vortices with central depressions have been observed in systems that successfully perform the inventive process. Whether the vortex has a central depression appears to depend on the speed of recirculation of the solution relative to the size of the container in which the solution is processed. Either type of vortex appears to be useful as long as there are at least two vortices with intersecting walls. Kinetic energy is believed to be added to the solution by turbulent flow resulting from collision of the intersecting vortex walls.

Turbulent flow is enhanced in a preferred embodiment by re-circulating the solution to be treated through a recirculation pathway such that solution withdrawn from ports in the bottom of a container is returned through return ports located so that the solution re-enters the container at high speed and in collision with the vortices at the point at which the vortices' walls are already in turbulent collision, thus adding to the turbulence of the flow and imparting further kinetic energy. In one such preferred embodiment the solution being returned to the tank was forced at high speed through fan shaped return ports positioned to direct the flow of the returning solution along the vertical length of intersection of the colliding vortices. The fan shaped return ports were designed to have the same total cross section as the conduit that feeds into them.

The method of the present invention has been practiced in both batch mode and flow- through mode with good results. In batch mode a tank or container was filled with a solution to be treated, and recirculation of the solution was started through a kinetic energy subsystem comprising a recirculation pathway. The pathway included conduit leading from ports in the bottom of a cylindrical tank to a pump outside the tank and from the pump to inlet ports on the side of the tank positioned to direct returning fluid to the vicinity of the intersecting walls of vortices arising from the exit ports. In some cases the reagent was added before circulation was started and in other cases reagent was added after circulation was already underway.

In flow'through mode the solution was re-circulated in the tank by means of a similar kinetic energy sub-system including a recirculation pathway that collected solution through a plurality of ports in the bottom of the tank and returned the solution to the tank through ports positioned to direct returning solution at the location within the tank of the intersecting vortex walls set up by the withdrawal of the solution. As in the batch system, the recirculation pathway in the fiow-through system included a pump for accomplishing movement of the reagent solution through the recirculation pathway. In the flow-through system, a portion of the treated effluent can be returned to the system. It has been observed that the treated effluent continues to reduce the amount of any remaining solids for some time after exiting the system. Diluting influent in a flow-thru system with recently treated effluent appears to add to the efficiency of the inventive process. The pump that extracts wastewater from the drain or drains and circulates it back into the container through the inlet ports can be any type of pump sufficient to perform this function. The pump is typically a centrifugal pump and may include a grinding function. There may be one or more circulating pumps, the number not being critical to the functioning of the device. Types of pumps will be determined by specific waste stream needs. In a preferred embodiment, there were two recirculating pumps plumbed so as to provide redundancy in circulating the wastewater. Redundancy enables alternative pumps to takeover full operation of the system while a pump with mechanical problems is replaced or repaired. The operating face of the centrifugal pumps showed no signs of cavitation when inspected after lengthy experimental testing.

In operation the solution was contained in a substantially closed system during recirculation so that the recirculating material is not allowed to vent to the atmosphere from the system. The system was closed with sufficient tightness to prevent leaking of any foam that might develop during recirculation. An expansion tank was installed in the batch process systems to receive and hold any foam that developed. Batch processing tanks usually included a sampling port for collecting samples for testing prior to emptying the system. The batch systems were usually emptied into municipal sewer systems after processing and testing were complete.

Foam generated in the flow-thru process was usually transferred along with treated solution from the processing tank to an optional injection tank of approximately equal size by gravity flow through a closed conduit. Treated solution produced by the flow-thru system was produced as effluent from the injection tank. The dwell time in the injection tank was effective to allow foam to dissipate before the effluent was finally produced. In some embodiments the injection tank included an optional pump for stirring the material or for emptying the injection tank when gravity flow could not be used. The device includes ports for loading influent solution and for producing effluent. In a fiow'thru system the influent stream has been loaded and the effluent stream has been produced in a variety of ways. In most embodiments influent was pumped into the processing tank where it displaced processed solution, which was pushed out of the processing tank and into the injection tank by the new influent. Generally speaking, influent can be added to the processing tank in a flow-thru system at any location and in any manner that doesn't interfere with the creation and maintenance of the colliding vortices. In a preferred arrangement, influent was added to the recirculating sub-system and effluent was produced through a port construction similar to that found in residential septic tanks. Sampling ports were positioned in the flow-thru system to enable sampling of influent, effluent from the recirculation tank and effluent from the injection tank. Each sampling port included a hand-operated valve that was opened from time to time to collect samples for testing from the influent, the effluent from the processing tank and the effluent from the injection tank.

When the system is used to treat municipal wastewater or sludge it may further include pre-loading grinders or macerators for reducing the size of solids in the wastewater or a bar screen for blocking large non-waste items such as rocks. Devices such as that described in connection with Fig. 3 have been found to operate without clogging when loaded with wastewater containing pieces no larger than about 3.0 inches in diameter. The particle size, however, can be much larger in larger systems and is restricted only by a desire not to clog the pump or pumps. The device also may include ports by which sensors can be placed in actual or optical contact with the solution to monitor parameters critical to determining its condition or its suitability for reintroduction to the environment. Sensors can monitor the turbidity of the solution, its oxygen concentration, and the like. Information obtained by the sensors can be used to control, for example, recirculation speed, the addition of reagent or other treatment materials, and the flow of material to be treated through the system in flow-thru embodiments. An experimental device was made from high density polyvinyl chloride

(HD'PVC) although other plastics and metals may be used. The device does not operate at high temperatures or pressures that would require more rugged materials. Surprisingly, suspended solids in constant moving contact with the inside of the container have not been found to degrade it.

Useful re-circulation speeds will depend on the size of the overall system. Satisfactory reduction of solids has been observed at speeds as low as 30 gallons per minute in smaller systems holding about 30 gallons of wastewater. Systems holding up to 100 gallons of waste water have been found to satisfactorily reduce the level of solids in wastewater at recirculation speeds of around 200 gallons per minute. Solids in WAS at a municipal waste treatment facility have been effectively reduced in a 1,200 gallon flow-thru tank re-circulating at about 5,000 gallons per minute. The lowest re-circulation speed at which any particular system/oxidizer combination is effective depends on a variety of factors such as the type and concentration of material constituting the solids and on the type and concentration of the reagent and cannot be determined in isolation.

The preferred maximum solids concentration in sludge for efficient use of the system was found to be about 2.5% when treated in a 1,200 gallon system at a recirculation speed of 5,000 gal/min while adding a 50% H₂O₂, solution as a reagent, although substantial reductions in solids have been shown in sludge having a solids concentration of 14% in such a system. It is sometimes useful to dilute sludge with wastewater (sewage plant influent) until the solids concentration reaches a level at which it can be re-circulated at an effective speed. In a municipal wastewater treatment plant, for example, solutions that have an undesirably high solids concentration can be diluted not only with water but also with plant influent or plant effluent. A viscous material from a petroleum processing plant was successfully dispersed in water with the aid of a surfactant and a mechanical mixer sufficiently for processing in the system of the present invention. In a preferred embodiment effluent from the inventive system was used to dilute influent WAS sludge, surprisingly resulting in successful reductions of solids with much less reagent. The reagent has been added to the solution both before and during the addition of kinetic energy. When the invention was practiced in batch mode, reagent was sometimes added to the solution before recirculation was started and at other times during recirculation. When the invention was practiced in a fiow-thru device, reagent normally was added simultaneously with the addition of kinetic energy. Reagent usually was added to the solution by means of a reagent sub-system. The reagent sub-system, especially in batch-processing systems, can be as simple as a closeable port in the top of a processing tank that can be opened to receive the reagent and then closed. In flow-thru embodiments the reagent has been injected into the moving solution at a variety of points. In one experiment, reagent was added to the influent stream. Reagent also has been injected into the recirculation pathway both before and after the recirculation pump or pumps. A preferred location for adding reagent is in the return port where the re-circulated solution is being returned to the processing tank and directed into the turbulence resulting from the colliding vortex walls. In one fiow-thru processing system the reagent was injected into the recirculating solution at a return port through a small diameter pipe positioned in a recirculation port whereby the recirculating solution formed a fast-moving annular jacket around the reagent stream as it exited the pipe. Addition of the reagent was metered by a control device that calculated the amount of reagent to inject by taking into account the density and flow rate of the influent.

The reagent may be any material that when added to the solution will result in a greater reduction of solids in the solution upon addition of kinetic energy than results when no reagent is added. It is believed that the full scope of useful reagents is not presently known. Oxidizers such as chlorine, hydrogen peroxide, ozone and oxygen have been tried, and each of them has been found to be useful to some degree. Sodium chloride also has been used as a reagent. At the present time the best results have been obtained in a batch processing system with chlorine supplied by household bleach and with hydrogen peroxide

(50% by volume) in a flow-through system, although it is to be understood that peroxide could be used in batch systems and chlorine could be used in flow-through systems.

Sodium chloride has been used as a reagent when salt and earth were mixed in an effort to duplicate seawater concentrations. The solution was batch processed in a 10 gallon table top experimental unit for eight minutes at 30 gallons per minute recirculation speed without the addition of additional reagent. The resulting solution was substantially clear of visible particles and did not taste of salt, suggesting the process is useful in desalination and for producing potable from available salty or turbulent sources. The amount of reagent used is waste-stream specific and may vary greatly from application to application, as can be seen in the examples below, and is believed to depend not only on the concentration of solids in the solution but also on the type of solid material carried by the solution. Different reagents will work more effectively in connection with specific materials. The type and amount of reagent that is useful in connection with a specific solution also may vary depending on whether a batch process or a flow-thru process is used. It has been observed that the amount of reagent added to obtain significant reductions in solids is stoichiometrically insufficient to result in the observed solids reductions by chemical reaction alone. In a fiow-thru process, for example, when the solution being treated was sludge having a strength of from about 2% to about 4% from a wastewater treatment plant, two to three liters of a peroxide reagent were added for each hundred gallons of influent with excellent results. When 100 gallon of raw sewage was batch processed, one quart of household chlorine bleach was determined by experimentation to provide excellent reduction of solids. Solids in a solution of starch solids were significantly reduced and the solution's BOD was substantially eliminated when treated in a 30 gallon bench top model of the system by recycling at about 30 gallons per minute in the presence a cup of household bleach. Pickle liquor from a steel plant showed approximately 80% reduction in solids and about 90% reduction in BOD after the addition to a 30 gallon solution of a quart of household bleach and turbulent kinetic energy. Additionally, a large amount of metallic iron was recovered from the system effluent by magnetic extraction. Likewise, optimal time for processing a specific solution-reagent combination in either a batch or fiow-thru process will vary greatly but can be determined for various waste streams by routine experimentation. Batch processing using a chlorine oxidizer, for example, has reduced solids in a raw sewage solution by over 90% in two minutes. In an experimental flow- thru system a 2% solution of aerobic sludge was added to a 1,200 gal. processing tank at a rate of about 100 gal/min and kinetic energy was added by recirculating it with hydrogen peroxide at a rate of about 5,000 gal/min. This flow-thru system obtained a solids reduction of about 90%. Although it takes about 12 minutes at a flow rate of 100 gal/minute for the influent sludge to pass through the processing tank, the minimum time required to accomplish the maximum possible solids reduction in such a system has not been determined.

Sampling and testing effluent from the processing tank and from the injection tank showed that the concentration of solids in the solution continued to reduce during the time spent in the injection tank. For example, waste activated sludge (WAS) from a municipal waste plant was treated by recirculating in a 1,200 gal. flow-thru tank for about 12 minutes at a recirculation speed of approximately 5,000 gal/min before flowing into an injection tank where it stayed for an additional 12 minutes before being returned to the waste plant headworks or dumped into drying beds. Samples were taken for testing as the influent entered the tank, as the treated material was transferred from the processing tank to the injection tank and as the treated solution was produced from the injection tank. An influent with 3,457 ppm suspended solids lost 79% of its suspended solids in the processing tank and an additional 6.8 percent before exiting the injection tank. The same material lost 69% of its total solids in the processing tank and another 10% in the injection tank.

Measurements of volatile solids and dissolved solids in the same solution also showed continued reduction in the injection tank. A different WAS stream having 3,440 ppm suspended solids showed a reduction of 11% in the processing tank and an additional 72% in the injection tank. Reductions of 96% of suspended solids in effluent from the injection tank have been shown. Narrative reports from personnel at a wastewater treatment plant where the experimental system returned its effluent to the headworks indicated that the levels of anaerobic sludge in clarifying tanks and settling ponds was reduced during the time of experimentation from an average depth of about eight feet in a 25-foot diameter settling pond to an average depth of less than three feet. There also were narrative reports of residual organic material visible in sample bottles upon arrival at the laboratory disappearing while awaiting processing. The reduction of solids in solutions treated by this invention appears continues for some time. The system of the present invention appears to change the concentration of a variety of solids in a typical solution. An aerobic sludge stream was processed by an experimental flow'thru device according to the present invention. Both the influent and effluent were tested for chemical oxygen demand (COD), soluble COD, ammonia (-n by distillation), potassium content, nitrogen (Kjeldahl total), total suspended solids and volatile suspended solids. The results showed that the COD was reduced by 91.6%, soluble COD increased by 58%, ammonia was reduced by 49%, phosphorous was reduced by 80%, nitrogen was reduced by 91%, total suspended solids were reduced by 69% and volatile suspended solids were reduced by 71%. Results taken on different days varied somewhat depending on the makeup of the sludge provided on each day; however the results given here are representative of the changes in solutions that can be expected.

Functioning systems for employing the present invention have been made in desktop, 100 U.S. gallon and 1,200 U.S. gallon sizes. In flow-through system the variables in the process were controlled by means of a touch screen monitor located in an adjacent room. It is understood the monitor could be located at some distance from the device and communication between the monitor and the screen could be via internet connection, telephone connection or radio signal. Results have been accurately measured and found to be substantially consistent over time, with most variances traceable to changes in the content and strengths of wastewater influent streams. Solids in influent wastewater and in sludge streams were assayed, and the results were compared with EPA standards, by procedures that are routine in wastewater treatment plants. For example, municipal wastewater and some industrial wastewater can be measured by its carbonatious biochemical oxygen demand (CBOD), by its chemical oxygen demand (COD) and by its NH₄ content. At the present time the Environmental Protection Agency's maximum acceptable levels for CBOD and NH₄ in treated wastewater that is discharged into rivers is 10 mg/L and 1 mg/L, respectively.

Municipal wastewater treatment plants also usually measure dissolved solids, volatile solids, suspended solids, and total solids in both influent and effluent. The reduction of solids in wastewater by the present invention has been demonstrated by each of these measurements. Although it is understood how to make and use the system, the chemical/physical reaction that results in relatively rapid reduction in the level of solids in a solution has not been fully characterized. It is known the phenomenon is related to the addition of a reagent and kinetic energy to a solution. It is believed at least some of the solids in the wastewater are oxidized. Although the use of chlorine as a reagent in batch processes usually resulted in residual chlorine in the treated solution, flow-through systems using hydrogen peroxide as a reagent tested negative for residual peroxide in the treated solution when the system was finely tuned. It is believed additional chemical/mechanical reactions, such as ionization, may occur because of the turbulence created in the solution during operation of the invention at suitably high speeds; however, the exact nature of such additional reactions has not been fully investigated to date. The amount of solids destroyed by the invention appears too great to be accounted for stoichometrically by the amount of oxidizer used. No significant heat of reaction is observed. A mass spectrographic analysis of effluent from the inventive system suggests that no synthetic volatile organic compounds are created by the process. Biological testing of a normalized sample of effluent from a flow- through device of the present invention when it was used to reduce solids in WAS passed biological screening for toxicity and mutagenicity.

The effluent appears to be saturated or supersaturated with oxygen. The elevated dissolved oxygen content of effluent from the present flow-through system allowed reduced use of blowers in a municipal wastewater treatment plant when effluent from the present experimental system was returned to the headworks of the plant. The mechanism that causes continued reduction in the volume of solids in the solution while the treated solution is in the injection tank is not fully understood at the moment but is thought to be related to the high oxygen content that the solution acquires during treatment. The exact increase in the oxygen content is not presently known, but it was observed that standard oxygen sensors instantly peg at 20% when contacted with the system effluent. The increased oxygen content is believed to be responsible for the appearance of small bubbles or "microbubbles" in the treated liquid or on the inside walls of containers holding treated effluent. The elevated oxygen level can last for some time, and has been useful in aerating the water in a sewage treatment plant in which the system effluent was returned to the headworks.

In another embodiment the continued activity of the effluent is used to improve the efficiency of the inventive system by returning a portion of the effluent from the injection tank to the process tank. The injection tank effluent has been returned to the process tank at a variety of locations, all with good results. In one embodiment effluent from the injection tank has been used to dilute the influent to the process tank at levels as high as two parts effluent to one part incoming WAS when then wastewater treated was a WAS slurry. Returning the treated effluent to the processing tank has been found to reduce the amount of reagent required by the system to effectively reduce solids in a solution.

The device of the present invention may be located at remote CSO outfalls and fitted with sensors for high water levels causing it to start operation when needed. The remotely located device, or a group of them, can be monitored or controlled from a central location using well known technologies such as telephone lines, radio and internet networks.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS FIG. 1 shows a single drain embodiment of the invention. FIG. 2 shows a multiple drain embodiment of the invention for use in batch processing. FIG. 3 shows a multiple drain embodiment of the invention suitable for use in flow- through processing.

FIG. 4 shows the currently optimal device for adding reagent in a device of the present invention.

DETAILED DESCRIPTION OF THE INVENTION FIG. 1 shows in schematic perspective view one embodiment of the present invention comprising a substantially rectangular container 1 having a capacity of about 30 gallons, although any size container may be useful, depending on the particular application. Internal features of the container are shown by dotted lines. Vortex port 2 is connected by pipe 3 to pump 4. Pipe 5 connects pump 4 with return port 6 on the side of container 1. Container 1 also supports fill connector 7, exit drain 8 and closed reagent port 9 which may be opened to add reagent to container 1 either before or during processing. Connector 7 and drain 8 include closeable valves 10 and 11 for controlling the flow of wastewater into container 1 and treated water away from container 1. Vortex port 2 is offset from the center of the bottom of container 1. When a solution comprising dissolved and suspended solids 18 is recirculated in container 1 by withdrawing it from container 1 through vortex port 6 by pump 4, a vortex 15, shown in dotted lines, having its small end at drain 2 is established. "Harmonic vortex" 16, also shown in dotted lines, also is established in the container. The vortices exist in the wastewater in container 1 although the surface of the wastewater can be substantially undisturbed and there are no sounds or other indications of cavitation. The shape of vortices 15 and 16 may be variable and dynamic, especially during the start of circulation. However, the edges of vortices 15 and 16 collide at a location generally designated as 17. Re-circulating wastewater enters container 1 in the vicinity of location 17 and is directed to location 17 by placement of port 6. The device of FIG. 1 was made of pre-cast PVC sheets assembled by PVC welding, with ports made by drilling followed by welding of PVC fittings. The pump used was an Armstrong open face centrifugal pump adapted for recirculating the water in the tank at the rate of 30 gallons per minute.

Fig. 2 shows in schematic perspective view a device 20 according to the present invention having multiple vortex ports 21, the device being suitable for batch processing of solutions. Closed tank 22 includes closable filling and reagent port 23. Port 23 can be positioned substantially anywhere on the tank surface that will be above the surface level of solution 24 during processing. In the preferred embodiment shown in Fig. 2 port 23 is positioned approximately above the location 25 of the intersection of vortices 26 and 26a that eminate from ports 23. Such positioning of port 23 allows reagent to be added at the location of greatest turbulence in solution 24.

In operation, solution 24 is withdrawn from device 2 through vortex ports 21 and conduit system 28 by centrifugal pump 27. Pump 27 is driven by motor 29. Vortices 26 and 26a develop around vortex ports 21 and intersect at location 25. Solution 24 is returned to device 20 through return conduit system 210 and return port 211. Return port 211 is positioned so that returning solution 24 is directed at high speed toward location 25, adding to the turbulence caused by the intersection of vortices 26 and 26a. After processing, the solution can be removed through port 212. Fig. 3 shows device 30 according to the present invention adapted for flow-through operation. Processing tank 325 includes vortex ports 31a, 31b and 31c positioned along its bottom and connected by conduit system 32 to centrifugal pumps 33a and 33b, which are operated by electrical motors 34a and 34b respectively. Conduit system 32 also is connected to solution supply conduit 35 through which a solution 37 to be treated is supplied. The use of multiple pumps and motors provide device 30 with the ability to continue in operation in the event one of them must be stopped temporarily for servicing, or the like.

Solution 37 that is withdrawn by pumps 33a and 33b through conduit system 32 is returned to device 30 through return conduits 38a and 38b, manifold 39 and return ports 313a and 313b, forming a recirculation pathway. In operation, vorticies 36a, 36b and 36c arise from vortex ports 31a, 31b and 31c as recirculation of solution 37 reaches higher speeds, creating areas of high turbulence 310a and 310b where the vortices intersect. Solution 37 is returned to device 30 through return ports 313a and 313b, which are positioned to direct the returning solution at high speed to the areas of turbulence 310a and 310b, further increasing the turbulence. Reagent from reagent supply tank 311 is added to recirculating solution 37 through return ports 313a and 313b and supply conduit 312. Sensor 314 can be used to measure the density of the incoming solution 37 in supply conduit 35. Results from the sensor can be sent through electrical cable 315 to valve 316 to regulate the flow of reagent as a function of the density of the incoming solution. Treated solution is displaced from tank 325 through exit port 317. Exit port 317 receives treated solution 37 from near the bottom of device 30 through feed tube 318. In the embodiment shown in Fig 3 treated solution 37 is fed by gravity into optional injection tank 319 through conduit 320. As described above, injection tank 319 is approximately the same size as device 30 and enables defoaming of treated solution 37. The continued reduction of solids after solution 37 leaves tank 325 was observed when samples of injection tank effluent were compared with effluent from tank 325 drawn at about the same time. Treated solution 37 is displaced from injection tank 318 through effluent port 321 and, in this illustrative example, returned to a municipal wastewater headworks through grating 322. Injection tank 319 may include pump 326 which operates through conduit 327 and distributor 328 to circulate treated solution 37 in injection tank 319. Pump 326 also can operate through conduit 327, conduit 329 and remote effluent port 330 to move treated solution 37 to a remote delivery point when tank 319 is positioned so that treated solution 37 cannot be delivered to a delivery point by gravity flow. Further, pump 326 can operate through conduit systems 329 and 331 to deliver treated solution 37 to influent solution in conduit 35 or to recirculating solution in conduit 32. Pump 326 and conduit system 329 also may be used to deliver treated solution to tank 325 through ports 332a and 332b; which, in the embodiment shown in Fig. 3, are positioned over areas of turbulence 310a and 310b, respectively. Ports for returning treated solution directly to tank 325 may be positioned at substantially any location that does not interfere with the creation of vortices with intersecting walls in solution 37.

Figs 4a and 4b show the currently optimal device 41 for returning recirculated solution 37 to the area of turbulence 313a or 313b. Device 41 comprises a conduit 42 that brings recirculated solution 37 through ports 313a or 313b in the wall of tank 325. Device 41 may comprise the end of manifold 39. End 45 of device 41 that is inside device 30 is reshaped so that it directs the flow of recirculated solution 37 into a vertical fan shape that strikes area of turbulence 310a or 310b along its length, maximizing the turbulence added by the recirculated solution 37.

Reagent is added to the recirculating solution through conduit 43, which is fed by supply conduit 312. Introducing the reagent at the point of maximum turbulence, as solution 37 exits shaped end portion 45 and substantially instantly contacts an area of turbulence such as 310a or 310b, is believed to maximize the efficiency of the operation of the device 30. Fig. 4b shows that the cross-sectional area of the reshaped conduit 42 does not form a nozzle. The inside diameter of the reshaped end of conduit 42 is approximately the same as the inside diameter of the portion of conduit 42 that has a circular diameter.

Examples:

Example 1

One hundred gallons of municipal sanitary waste (sewage) was placed in the device described in connection with FIG. 2. Samples of the untreated sewage were set aside for subsequent testing. Two liters of 6% chlorine were added to the waste. The device was run as described in connection with FIG. 2 for four minutes after which further samples were obtained for testing. Tests for carbonatious biochemical oxygen demand (CBOD), carried out by EPA method 405.1 showed 199 mg/L in the raw sewage and 8.8 mg/L in the treated wastewater, a 95.6% reduction. Tests for NH₃ done by EPA method 160.2 showed a concentration of 15.1 mg/L in the raw sewage and 1.69 mg/L in the same wastewater after treatment, an 88.8 percent reduction. The CBOD and NH₃ levels after 10 minutes of processing were below EPA maximum levels for the reintroduction of sewage treatment plant effluent into rivers (10 mg/L for CBOD and 1.0 mg/L for NH₃.)

Following the recirculation process the treated material was passed through the filter and emptied into a municipal sewer. No sludge or sludge-like material collected in the filter, and no sludge or particulate matter remained in the container or plumbing. The small amount (about a thimble full) of material found in the filter was tested by spectrographic methods and found to contain no organics.

Example 2 The test as described in Example 1 was repeated using sanitary waste from a Middle

School septic system surge tank. The CBOD assay showed a level of 223 mg/L prior to processing and a level of 2.50 after 4 minutes of processing, a 98.9% reduction. The NH₃ test showed 11.1 mg/L prior to processing and 0.358 mg/L after processing, a 98.6% reduction. A small amount of the processed fluid, which had originally contained identifiable human waste, was consumed as drinking water by the inventor immediately following processing with no ill effects.

An assay for residual chlorine performed on the samples retained following the test showed unconsumed oxidizer that could be neutralized with any well-known neutralizing agent for chlorine. Sodium thiosulphate was used in this instance.

Example 3

Additional raw sewage from a school septic system surge tank was processed as in

Examples 1 and 2 except that samples also were extracted at two, four, six and eight minutes for subsequent analysis. Testing showed CBOD levels being reduced from 590.0 mg/L to

11.1 mg/L with the results being substantially complete (99.9925% complete) after two minutes, and NH₃ levels being reduced from 42.3 mg/L to 1.67 mg/L after eight minutes of processing.

Examples 1, 2 and 3 indicate that CBOD levels and NH₃ levels in municipal waste can be reduced dramatically in a very short period of time by the device and method of the present invention and that only inorganic materials of a size sufficient to be collected in a filter remain in the solution.

Example 4 Process waste obtained from a commercial food processor was processed in the device described in connection with FIG. 1 for four minutes. An assay of the waste prior to processing showed a CBOD level of 432,000 mg/L. An assay of the material after 10 minutes of processing showed a CBOD level of 4.3 mg/L. A second sample of material showed a CBOD of 156,000 mg/L prior to processing a 8.4 mg/L after four minutes of processing. Example 4 indicates the usefulness of the present device and method in reducing

CBOD levels in industrial waste or in pre-treating industrial waste prior to its introduction into municipal sewer systems.

Example 5 Waste material from a nursing home, including medical materials, discarded bandages, syringes, and the like, was processed according to Example 4. The waste material showed a CBOD level of 69.0 mg/L prior to processing and a CBOD level of 3.1 mg/L after processing for four minutes. The NH3 concentration of the nursing home waste was 12.1 mg/L prior to testing and 0.74 mg/L after testing.

Example 5 indicates the usefulness of the device and method of the present invention is disposing of infectious waste.

Example 6 Two samples of process waste from an oil refinery were treated as in Examples 4 and 5 except that a surfactant was added to help put the tar-like waste into an aqueous solution.

The samples were tested for CBOD's before and after processing. The first sample showed

CBOD levels of 249,000 mg/L before processing and 3.2 mg/L after processing for four minutes. The second sample showed CBOD levels of 31,000 mg/L prior to processing and 1.0 mg/L after processing.

Example 6 shows the usefulness of the device and method of the present invention in treating petroleum-based industrial waste and indicates that process aids, such as surfactants, do not interfere with the operation of the device.

Example 7

Two samples of embalming waste were treated for eight minutes as described in Example 4. Prior to processing, the samples were tested for Pseudomonas aeruginosa (31,000 cfu/ml and 205,000 cfu/ml), salmonella choleraesuis (1,578,000 cfu/ml and 693,000 cfu/ml) and staphylococcus aureus (400,000 cfu/ml and 1,070,000 cfu/ml). After eight minutes of processing as described in Example 4 tests for these organisms on all the samples shows 0 cfu/ml (a 10 log kill). Surprisingly, further testing of the treated waste showed no evidence of chloramines, well known carcinogens.

Example 8 Anaerobic sludge produced by a municipal wastewater treatment plant was processed in the experimental flow-through process as described in connection with Fig. 3 and the effluent was delivered to a drying bed having a sand bottom that allowed liquids to return to the headworks of the treatment plant. Over three months about 500,000 U.S. gallons of treated solution was delivered to a single drying bed. Thereafter, five truck loads of material were removed from the floor of the drying bed and disposed of in a landfill. According to wastewater treatment plant records, 500,000 gallons of untreated sludge of the same solids concentration delivered to identical drying beds resulted in 60 truckloads of material being transported to a landfill. The reduction in material that had to be hauled away was 91.3%. Records also show that cleaning of dried material from identical drying beds was required after receiving only 35,000 U.S. gallons of untreated sludge. The treated material appeared to be substantially free of FOG's at the time it was delivered to the drying bed. The present invention appears not only to reduce the amount of solids in a solution but also to improve dewatering of any remaining material.

Example 9

A sludge slurry comprising anaerobic sludge from a municipal wastewater treatment plant was processed in an experimental 1,200 gal. flow-through system of the type described in Fig. 3. The contents of the system were re-circulated as described in connection with Fig. 3 at an average rate of about 5,000 gal. per minute. The rate of flow of the sludge solution into and out of the system was monitored and recorded as was the rate of addition of oxidizer. The oxidizer was hydrogen peroxide (50% V/V in aqueous solution). The optically measured density of the influent sludge solution varied over time, and the rate of addition of oxidizer was adjusted in response. Two sets of samples were drawn from the system influent and effluent at different influent densities and were assayed for certain parameters as shown in

Table 9. Table 9 also shows the rate of flow of the influent and the amount of reagent added. The following is a key to abbreviations used in Table 9. TSS = total suspended solids VSS = volatile suspended solids COD = chemical oxygen demand TKN = total Kjeldhal nitrogen Ammonia-N = Ammonia N by distillation TP = total phosphorous

Table 9 Test Solution 1 Solution 1 Percent Solution 2 Solution 2 Percent

Influent Effluent Reduction Influent Effluent Reduction

The data in Table 9 show that the system of the present invention is useful to quickly and effectively reduce total suspended solids, volatile suspended solids, total COD's nitrogen and ammonia in sludge from a wastewater treatment plant.

It will be apparent to those of ordinary skill in the art that a variety of specific devices can be constructed to provide a container in which drains are positioned to set up contacting vortices in a liquid being treated with oxidizers, and all such structures are intended to be within the scope of the following claims. It will also be apparent to those in the art that the device and method described herein can be used to treat many different types of infectious, industrial and municipal wastes in a variety of volumes. All such applications are intended by the inventor to be within the scope of the following claims.

With the above description it is to be understood that the DEVICE AND METHOD FOR CHANGING THE CONCENTRATION OF SOLIDS IN A SOLUTION is not to be limited to the disclosed embodiment. The features of the device and method are intended to cover various modifications and equivalent arrangements included within the spirit and scope of the description. The drawings together with the summary and detailed descriptions given above serve to explain the principles of the device and method. It is understood, however, that the device is not limited to only the precise arrangements and instrumentalities shown.

Claims

Claims:

1. A method for changing the concentration of solids in a solution in a closed system, the method comprising: a. adding a reactant to the solution; and b. adding an effective level of kinetic energy to the solution.

2. The method of claim 1 wherein subjecting the solution to an effective level of kinetic energy comprises causing turbulent flow in the solution.

3. The method of claim 2 wherein causing turbulent flow in the solution comprises establishing vortices with at least partially intersecting walls in the solution.

4. The method of claim 3 wherein establishing vortices with at least partially intersecting walls in the solution comprises withdrawing solution from a container holding a quantity of the solution through one or more ports positioned so as to set up at least two such vortices.

5. The method of claim 4 further comprising returning withdrawn solution to the container.

6. The method of claim 5 wherein withdrawn solution is returned to the container at substantially the location of the intersection of the at least partially intersecting walls.

7. The method of claim 5 wherein the quantity of solution is a batch that is subjected to an effective level of kinetic energy in the presence of a reactant for a selected time.

8. The method of claim 5 wherein the quantity of solution is a portion of a stream of solution flowing through a closed system.

9. The method of claim 1 wherein the solids in the solution comprise at least one organic material.

10. The method of claim 4 wherein the organic material comprises material selected from the group consisting of food processing waste and by-products, restaurant grease, municipal raw sewage, sludge produced by wastewater treatment plants, material from septic systems, animal waste, medical wastes, biohazards, petroleum processing waste and byproducts, metal processing residue, industrial wastes and by-products, marine bilge water, marine wastewater, river water, lake water, seawater and mixtures thereof.

11. The method of claim 1 wherein the solution is aqueous.

12. The method of claim 1 wherein the reactant is selected from the group consisting of oxygen, ozone, chlorine and peroxide.

13. The method of claim 1 wherein the reactant is added in an amount stoichiometrically insufficient to accomplish the resulting change in concentration of solids in the treated solution.

14. The method of claim 9 wherein the solution comprises an aqueous solution of municipal waste treatment sludge having an organic solids concentration of about 1.5 percent by volume, wherein the reagent is a 50% aqueous solution of peroxide, wherein treated solution is produced at a rate of about 300 U.S. gallons per minute and wherein the produced solution is replaced at a rate of about 300 U.S. gallons per minute with a material comprising reagent and solution in a ratio of about 2 L. reagent for each 100

U.S. gallons of solution.

15. A system for changing the concentration of solids in a solution to produce a treated solution, the system comprising: a. a closed container suitable for holding a quantity of the solution; b. at least one kinetic energy subsystem associated with the container for adding an effective level of kinetic energy to the solution; and c. at least one reagent subsystem associated with the container, the reagent subsystem adapted for adding reagent to the solution.

16. The system of claim 15 wherein the kinetic energy subsystem comprises a recirculation pathway adapted to establish vortices with colliding walls in the solution in the closed container.

17. The system of claim 16 wherein the recirculation pathway comprises at least one exit port in the container for withdrawing solution, at least one return port for returning the solution to the container at substantially the location of the intersection of the walls of the at least two vortices in the solution and at least one pump for withdrawing the solution through the at least one exit port and returning the solution through the at least one return port at a rate sufficient to produce turbulent flow in at least a portion of the solution in the container.

18. The system of claim 17 wherein the recirculation pathway comprises at least one shaped return port, said shaped return port adapted for directing the flow of the solution to the location of the intersection of the walls of the vortices.

19. The system of claim 18 wherein the reagent is added to the solution through a probe extending into the recirculation pathway and adapted to deliver reagent into a jacket of the solution in turbulent flow.

20. The system of claim 19 further comprising an influent port for receiving a supply of material comprising untreated solution and, optionally, treated solution and an effluent port for delivering treated solution, the system adapted for flow-through operation.

21. The system of claim 20 further comprising an injection tank for receiving and storing treated solution delivered through the effluent port.

22. The system of claim 15 adapted for changing the concentration of solids in a solution comprising raw sewage or an aqueous slurry of sludge produced by wastewater treatment.

23. The system of claim 24 wherein the exit port is adapted to deliver treated solution, either directly or through a holding tank, to a drying bed, to the headworks of a wastewater treatment plant or to the environment.

24. A method for improving dewatering in sludge comprising treating sludge according to the method of claim 1 wherein any remaining solids in the effluent separate more readily from the liquid effluent.

25. The method of claim 1 wherein the solution comprises seawater and wherein sodium chloride in the seawater is the reagent.

26. The method of claim 1 wherein the solution comprises water from natural sources.