JP2016195997A - System and method for reducing sludge produced by wastewater treatment facility - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide methods of improving sludge removal and maintaining effluent quality.SOLUTION: The invention relates to a method comprising: directing an incoming wastewater stream to a treatment facility, the stream having a flow of at least 20,000 gallons per day, and the incoming wastewater stream having at least 50 mg/L of solids and 100 mg/L of BOD; and removing solids and BOD from the incoming wastewater stream in the treatment facility to provide a final effluent stream. The step of removing solids and BOD comprises: adding a treatment batch containing functional microbes of one or more strains from a biofermentor for treatment of the wastewater stream; and subsequently applying the wastewater stream to biological wastewater treatment using functional microbes. The final effluent stream has less than 10% of the solids of the wastewater stream and less than 10% of the BOD of the wastewater stream. The removal of solids and BOD yields less than about 0.25 pounds of secondary sludge per pound of BOD removed.SELECTED DRAWING: None

Description

  Wastewater resulting from domestic and industrial water is usually sent to a treatment facility that removes various physical, chemical and biological contaminants and collected before being discharged to the water receptor. Many public and private processing facilities use both physical and biological processing methods to perform the necessary processing. Physical methods (including screening, gliding and physical sedimentation methods) are effective in removing larger and heavier solids in wastewater. However, lighter and smaller solids and other soluble contaminants in wastewater cannot be removed by physical methods. For these pollutants, biological treatment methods such as activated sludge method and sprinkling filter bed method are usually used.

  In recent years, regulations on pollutant emissions from municipal wastewater treatment systems have become more stringent. In response, many municipalities have either deployed new wastewater treatment systems or modified existing systems to reduce pollutant emissions. There are many forms of pollutants, most commonly biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), ammonia, total nitrogen, nitric acid. Nitrous acid and phosphorus.

  Biological treatment systems such as conventional activated sludge systems and membrane bioreactors are one way to reduce pollutants in influent wastewater. The term “inflow” refers to waste water or other liquid (raw (untreated) or partially treated) that flows to a reservoir, basin, treatment process or treatment plant or treatment facility. The biological treatment system is designed and operated so that an appropriate amount of activated sludge is retained and the pollution load contained in the water treated by the system is appropriately reduced. The net excess activated sludge produced (defined as weight) is related to the solids residence time (SRT) of the system. The minimum SRT required for the treatment of various contaminants under various conditions is generally well known. As long as the concentration of the activated sludge stream and the settleability of the activated sludge toward the sedimentation basin or clarifier are within reasonable limits set by design parameters depending on the area of the sedimentation basin or clarifier and the characteristics of the activated sludge The activated sludge system can retain the activated sludge through the use of a sedimentation or clarification device and maintain an appropriate SRT to treat the contaminants. Membrane bioreactor systems retain activated sludge through the use of membrane filtration equipment and can be operated at activated sludge concentrations significantly higher than typical activated sludge concentrations in conventional activated sludge systems, but accidentally The ability to handle high flow rates is limited.

  When pollution loads or water treatment capacities are reached, the treatment facility will breach acceptable limits, potential federal or state enforcement actions, domestic growth and industrial development within the service area where the collection system is effective. Face risks such as restrictions or outages. Typically, wastewater treatment facilities are physically expanded to meet increased water load needs. However, physical expansion is expensive and sometimes requires additional land, and in cities, such land is not always available adjacent to existing facilities, and such Land is more expensive.

  Accordingly, it is desirable to find a way to increase volume or mass pollution load and water treatment capacity without the need for physical equipment expansion. A significant advantage of the present invention over conventional sludge processes is that the volume pollutant load can be substantially increased by adding a biofermentor to existing equipment. In addition, it is also a feature and advantage of the present invention that the enhanced sludge process produces biological sludge with improved sedimentation characteristics. Improved sedimentation characteristics allow for increased water load without the need to increase the size of the physical elements of the activated sludge system, as net sludge waste and / or generation is lower. . Another advantage is that there is less chemical sludge, labor costs due to less biological sludge to be treated and discarded in the sludge treatment process, which typically accounts for 40-50% of the operating costs of wastewater treatment facilities. The operating cost such as cost, energy cost and transportation cost is reduced. For similar reasons, a new wastewater treatment plant can be built on a smaller scale with a greatly reduced need for sludge treatment facilities, i.e. at a lower capital cost than known systems. For existing wastewater treatment systems that are in need of improvement, it may be possible to eliminate the need for capital increases or delay some or all of the expansion. In addition, the time interval for discarding biological sludge is extended by 25-50% from the activated sludge process to an aerobic or anaerobic digester and from the process to a dewatering step such as dry bed, pressure filtration or centrifugation. Can be extended by ~ 50%. This additional time means less labor requirements, less equipment, less energy usage, and less chemical usage.

  The present invention relates to an improvement in sludge removal and a method for maintaining the quality of discharged water. The method directs an influent wastewater stream to a treatment facility, wherein the influent wastewater stream is at a flow rate of at least 20,000 gallons per day and the influent wastewater stream is at least 50 mg / L solids And at the treatment facility, solids and BOD are removed from the incoming wastewater stream to obtain a final discharge stream: where the final discharge stream is less than 10% solids of the wastewater stream And having a BOD of less than 10% of the wastewater stream; removing solids and BOD yields less than about 0.25 pounds of secondary sludge per pound of removed BOD. In this method, the incoming wastewater stream may have at least about 100 mg / L solids and 200 mg / L BOD, with the removed solids being less than about 0.25 pounds secondary per pound of removed BOD. Sludge may be used. In this method, the influent wastewater stream may have at least about 100 mg / L solids and 400 mg / L BOD, with the removed solids being less than about 0.25 pounds secondary per pound of removed BOD. Sludge may be used. In this method, the influent wastewater stream may have at least about 50 mg / L solids and 100 mg / L BOD, with the removed solids being less than about 0.125 pounds of secondary per pound of removed BOD. Sludge may be used. In this method, the incoming wastewater stream may have at least about 100 mg L solids and 200 mg / L BOD, and the removed solids are less than about 0.125 pounds of secondary sludge per pound of removed BOD. There may be.

  In another embodiment, the invention relates to a method for improving sludge removal and maintaining effluent quality. The method directs an influent wastewater stream to a treatment facility, wherein the influent wastewater stream is at a flow rate of at least 20,000 gallons per day and the influent wastewater stream is at least 50 mg / L solids and Having a BOD of 100 mg / L; at the treatment facility, solids and BOD are removed from the incoming wastewater stream to obtain a final discharge stream: wherein the final discharge stream is less than 10% solids of the wastewater stream And having a BOD of less than 10% of the wastewater stream; removing solids and BOD yields less than about 0.25 pounds of biological sludge per pound of removed BOD. In this method, the incoming wastewater stream may have at least about 100 mg / L solids and 200 mg L BOD, and the removed solids were less than about 0.25 pounds of biological sludge per pound of removed BOD. May be. In this method, the influent wastewater stream may have at least about 100 mg L solids and 400 mg / L BOD, and the removed solids were less than about 0.25 pounds of biological sludge per pound of removed BOD. May be. In this method, the incoming wastewater stream may have at least about 50 mg / L solids and 100 mg / L BOD, and the removed solids are less than about 0.125 pounds of biosludge per pound of removed BOD. It may be. In this method, the influent wastewater stream may have at least about 100 mg / L solids and 200 mg / L BOD, the removed solids being less than about 0.125 pounds of biosludge per pound of removed BOD. It may be.

  In another embodiment, the invention relates to a method for improving sludge removal and maintaining effluent quality. The method directs an influent wastewater stream to a treatment facility, wherein the influent wastewater stream is at a flow rate of at least 20,000 gallons per day and the influent wastewater stream is at least 50 mg / L solids and Having a BOD of 100 mg / L; at the treatment facility, solids and BOD are removed from the incoming wastewater stream to obtain a first final discharge stream: wherein the first final discharge stream is a wastewater stream Having less than 10% solids and less than 10% BOD of the wastewater stream; treating the effluent stream by adding a treatment batch from the biofermentor, thereby reducing the solids and BOD in the final effluent stream Reducing the weight of the removed sludge by at least about 10% without increasing. In this way, the processing batch can be added to an anaerobic digester, a conditioning pond and / or a primary clarifier. In this way, the weight of the removed sludge can be reduced by at least about 25% without increasing the solids and BOD in the final discharge stream. In this way, the weight of the removed sludge can be reduced by at least about 50% without increasing the solids and BOD in the final discharge stream.

  In yet another embodiment, the present invention relates to a method for improving sludge removal and maintaining effluent quality. The method directs an influent wastewater stream to a treatment facility, wherein the influent wastewater stream is at a flow rate of at least 20,000 gallons per day, and the influent wastewater stream is at least 50 mg / L biosolids and Having a BOD of 100 mg / L; at the treatment facility, removing the biosolids and BOD from the incoming wastewater stream to obtain a final discharge stream: where the final discharge stream is less than 10% of the wastewater stream And having a BOD of less than 10% of the wastewater stream; removing solids and BOD yields less than about 0.25 pounds of biosolids per pound of removed BOD. In this method, the sludge may be primary sludge, biological sludge, and / or the sludge may include primary sludge and biological sludge. In this method, the incoming wastewater stream may have at least about 100 mg / L solids and 200 mg / L BOD, and the removed solids are less than about 0.25 pounds of biosolids per pound of removed BOD. It may be. In this method, the incoming wastewater stream may have at least about 100 mg / L solids and 400 mg / L BOD, and the removed solids are less than about 0.25 pounds of biosolids per pound of removed BOD. It may be. In this method, the influent wastewater stream may have at least about 50 mg L solids and 100 mg / L BOD, and the removed solids are less than about 0.125 pounds of biosolids per pound of removed BOD. May be. In this method, the incoming wastewater stream may have at least about 100 mg / L solids and 200 mg / L BOD, and the removed solids are less than about 0.125 pounds of biosolids per pound of removed BOD. It may be.

  In a further embodiment, the invention relates to a method for improving sludge removal and maintaining effluent quality. The method directs an influent wastewater stream to a treatment facility, wherein the influent wastewater stream is at a flow rate of at least 20,000 gallons per day and the influent wastewater stream is at least 50 mg / L solids and Having a BOD of 100 mg / L; at the treatment facility, solids and BOD are removed from the incoming wastewater stream to obtain a final discharge stream: wherein the final discharge stream is less than 10% solids of the wastewater stream And having a BOD of less than 10% of the wastewater stream; removing solids and BOD yields less than about 0.25 pounds of secondary sludge per pound of removed BOD. In this method, the influent wastewater stream may have at least about 100 mg / L solids and 200 mgL BOD, with the removed solids being less than about 0.25 pounds of secondary sludge per pound of removed BOD. There may be. In this method, the influent wastewater stream may have at least about 100 mg / L solids and 400 mg / L BOD, with the removed solids being less than about 0.25 pounds secondary per pound of removed BOD. Sludge may be used. In this method, the incoming wastewater stream may be at least about 50 mg / L solids and 100 mg L BOD, and the removed solids are less than about 0.125 pounds of secondary sludge per pound of removed BOD. Also good. In this method, the influent wastewater stream may have at least about 100 mg / L solids and 200 mg / L BOD, and the removed solids are less than about 0.125 pounds of secondary per pound of removed BOD. Sludge may be used.

  In yet another embodiment, the present invention relates to a method for improving sludge removal and maintaining effluent quality. The method directs an influent wastewater stream to a treatment facility, wherein the influent wastewater stream is at a flow rate of at least 20,000 gallons per day and the influent wastewater stream is at least 50 mg / L solids and Having a BOD of 100 mg / L; at the treatment facility, removing solids and BOD from the incoming wastewater stream to a final discharge stream: where the final discharge stream is less than 10% solids of the wastewater stream And having a BOD of less than 10% of the wastewater stream; removing solids and BOD yields less than about 0.25 pounds of biological sludge per pound of removed BOD. In this method, the incoming wastewater stream may have at least about 100 mg / L solids and 200 mg L BOD, and the removed solids were less than about 0.25 pounds of biological sludge per pound of removed BOD. May be. In this method, the incoming wastewater stream may have at least about 100 mg / L solids and 400 mg / L BOD, and the removed solids are less than about 0.25 pounds of biological sludge per pound of removed BOD. It may be. In this method, the incoming wastewater stream may have at least about 50 mg / L solids and 100 mg / L BOD, and the removed solids are less than about 0.125 pounds of biosludge per pound of removed BOD. It may be. In this method, the influent wastewater stream may have at least about 100 mg / L solids and 200 mg / L BOD, the removed solids being less than about 0.125 pounds of biosludge per pound of removed BOD. It may be.

FIG. 1 is a flow diagram of a conventional activated sludge process. FIG. 2 is a schematic diagram for explaining a conventional wastewater treatment method. FIG. 3 is a schematic diagram illustrating an exemplary wastewater treatment sequence and process. FIG. 4 is a schematic diagram illustrating an exemplary wastewater treatment sequence and process.

  Various embodiments of the present invention provide wastewater treatment systems and methods. Many embodiments of the present invention accept influent water that exceeds one or more environmental standards, including restrictions on BOD, COD, TSS, ammonia, nitric acid, nitrous acid, total nitrogen, and phosphorus levels, It is possible to discharge wastewater that meets the environmental standards. Such emission environmental standards are managed by the National Pollutant Discharge Elimination System (NPDES). Aspects of the invention can be selected to maximize treatment efficiency, minimize operational costs in “normal” operation, and to allow for acceptable effluent quality in the same system, even during high inflow periods.

  Specifically, the present invention relates to a wastewater treatment method in which net biological sludge that is discarded or generated is reduced.

Overview In the practice of the present invention, unless otherwise noted, conventional wastewater treatment engineering techniques are used that are within the ordinary skill of a Class 1 or Class A qualification or degree environmental engineer. The definition of such techniques and terminology is fully explained in the following documents for certification of engineers: Operation of Wastewater Treatment Plants Manuals, A Field Study Training Program, 4th Edition, Volume 1 and Ut. Sacmento, 1998; Industrial Waste Treatment, A Field Study Training Program, California State University, Sacmento, Trend Ahead, 1991; cond Edition, California State University, Sacramento, 1993; and Operation and Maintenance Wastewater Collection Systems, A Field Study Training Program, Fourth Edition, Volumes 1 and 2, California State University, Sacramento, 1993.

  Wastewater can be treated near the place where it occurs (in septic tanks, biofilters or aerobic treatment systems), or through pipe networks and pumping stations called wastewater recovery systems, to the treatment plant. Can be transported and recovered. Wastewater recovery and treatment is typically subject to local, state and federal regulations and standards. Industrial wastewater may require special treatment processes.

  Typically, wastewater treatment includes three stages called primary, secondary and tertiary treatment.

  The primary or settling process / stage consists of holding the incoming wastewater temporarily in a tranquil basin where heavy solids can sink to the bottom, while fats, oils, greases and light solids float on the surface. Sedimented and suspended matter is removed and the remaining liquid can be drained or subjected to secondary treatment.

  The term “inflow” refers to waste water or other liquid (raw (untreated) or partially treated) that flows to a reservoir, basin, treatment process or treatment plant or treatment facility.

  In the primary stage, the wastewater flows into a large tank commonly referred to as the “first clarification tank” or “first sedimentation tank”. The term “clarification tank” refers to a sedimentation tank or sedimentation basin that holds wastewater until heavy solids settle to the bottom and light matter floats to the surface of the water. The tank is large enough to allow sludge to settle and float and scoop up suspended substances such as grease and oil. The primary purpose of the primary sedimentation stage is to produce a nearly uniform liquid that can be biologically processed and sludge that can be processed separately. Primary sedimentation tanks are usually equipped with a mechanically driven scraper, which can continuously extrude the recovered sludge to a hopper at the bottom of the tank for delivery to a further sludge treatment stage.

  The term “sludge” encompasses “primary sludge”, “secondary sludge” or “biological sludge” and various “solids”, and these three terms are used herein to interchangeably. Used to mean excess biomass resulting from biodegradation of organic matter during secondary (biological) processing.

  The term “primary sludge” refers to semi-liquid waste that is obtained from a sedimentation process using a primary process and has not been further processed. This typically includes organic matter, paper, feces / solids that settle to the bottom of the first clarifier and have been removed or drowned from a pretreatment or conditioning pond. The primary sludge also contains secondary sludge, and secondary and primary sludge co-sedimentation takes place in the first clarification tank.

  “Secondary sludge” or “biological sludge” means surplus biomass resulting from biodegradation of organic matter during secondary treatment (biological treatment). Secondary sludge includes activated sludge, mixed sludge, and coagulated sediment sludge.

  The term “solid” means primary sludge, secondary sludge or both.

  The term “biosolid” refers to a primary solid product produced by a wastewater treatment process.

  Primary and secondary sludge are combined by solids concentration / reduction by anaerobic digestion. The aerobic process is usually just a secondary process.

  Sludge is typically removed from wastewater to maintain solids that accumulate in biological processes. Following the removal of sludge, it goes through a sludge treatment process. This process uses aerobic or anaerobic digestion to reduce sludge and then uses chemicals (flocculating agents or polymers) and then concentrates in machinery, eg centrifuges, belt presses, from initial treatment to land use. There are various forms until final treatment by incineration and landfill. Sludge disposal and subsequent processing processes are important to maintain the food: microbe ratio (F: M ratio) in the activated sludge plant. The F: M ratio is a key parameter in the determination and control of effluent quality. The term “F: M ratio” refers to the bait: microbe ratio and is a measure of the bait provided to bacteria in an aeration tank.

  Secondary treatment removes dissolved biological material and suspended biological material. The secondary treatment is typically performed by resident aquatic microorganisms in the managed habitat, i.e. a biological wastewater treatment system. Secondary treatment requires a separation step that removes microorganisms from the treated water prior to discharge or tertiary treatment.

  Tertiary processing is often defined as something other than primary and secondary processing. Treated water is disinfected chemically or physically (eg, by lagoon and microfiltration) before being discharged into waterways, rivers, bays, lagoons or wetlands, or golf courses Can be used for irrigation, green path or park. If it is clean enough, it can also be used for groundwater recharge or agricultural purposes.

  In general, the influent wastewater may be pretreated. Pretreatment removes large material that can be easily recovered from raw wastewater before damaging or clogging the pump and skimmer of the primary clarifier. This is most commonly done by automated mechanical raked bar screens in large modern plants, but in smaller or non-modern plants, manually washed screens. Can be used. The sweeping action of the mechanical bar screen is typically adjusted according to the deposition on the bar screen and / or the flow rate. Solids are collected and discarded in landfills or incinerated.

  The pre-treatment can also include sand or gravel channels or chambers that carefully control the rate of influent wastewater to sink sand, gravel and stone.

  Following tertiary treatment, the accumulated sludge must be treated and disposed of in a safe and effective manner. The purpose of digestion is to reduce the amount of microorganisms present in the solid and the number of pathogenic microorganisms. The most common treatment options include anaerobic digestion, aerobic digestion and composting, and incineration can also be used.

  The choice of wastewater solids treatment method depends on other conditions specific to the amount and location of the resulting solids. However, generally, composting is often used for small-scale applications, followed by aerobic digestion and anaerobic digestion for large-scale municipal applications.

  Anaerobic digestion is a biological process that takes place in the absence of oxygen. This process can be either hot digestion where the sludge is fermented in tanks at temperatures above 55 ° C. or mesophilic digestion at temperatures near 36 ° C. Although shorter retention times (and thus smaller tanks) can be tolerated, hot digestion is more expensive in terms of energy consumption to heat the sludge.

  One major feature of anaerobic digestion is the generation of biogas (the most common component is methane), which can be used for power generation and / or boiler heating purposes.

  Aerobic digestion is a biological process that occurs in the presence of oxygen. Under aerobic conditions, microorganisms ingest organic matter immediately and convert it to carbon dioxide. The operating cost of aerobic digestion is the energy used by the blowers, pumps and motors needed to add oxygen to the process, even though stone fiber filter methods have recently emerged that use natural airflow for oxygenation. Therefore, it is significant. Aerobic digestion can also be accomplished by oxidizing the sludge using a jet aerator, which is also less expensive than the conventional method but is costly.

  Composting is also an aerobic process that involves mixing sludge and carbon sources such as sawdust, straw or wood chips. In the presence of oxygen, microorganisms digest both wastewater solids and added carbon sources while generating large amounts of heat.

  Sludge incineration is less common due to exhaust problems and the auxiliary fuel (typically natural gas or fuel oil) required for combustion of low calorific value sludge and evaporation of the remaining water. Multi-stage incinerators and fluidized bed incinerators that require high residence times are the most common systems used to burn wastewater sludge. There may also be co-combustion in municipal waste-energy plants. This option is less expensive assuming that the facility already exists for solid waste and does not require supplemental fuel.

  If liquid sludge is produced, further processing may be required to make it suitable for final disposal. Typically, sludge is concentrated (dehydrated) to reduce the amount that is transported to an isolation site for disposal. There is no way to completely eliminate the need to dispose of biosolids. However, in some towns, additional steps are being taken to overheat wastewater sludge and convert the “cake” into small pelletized granules. It has a high nitrogen and other organic content and is used as a fertilizer. This product is then sold to local and lawn farmers as a soil conditioner or fertilizer, reducing the land required for disposal of sludge in landfills. The removed liquid, also referred to as the centrate, is typically reintroduced into the wastewater process.

  There are different types of wastewater treatment systems and processes. As an example of the wastewater treatment system, there is an activated sludge method as described in the flowchart of FIG. In general, during the pretreatment process, influent wastewater is first screened to remove roots, rags, empty cans and large debris. They are then transported to landfills or, if possible, crushed and returned to the plant stream. Next, sand and pebbles are removed from the incoming wastewater during the sand grain removal process, and the wastewater is pre-aerated and activated to facilitate oil removal. The influent wastewater is then passed through a flow meter to measure and record the flow. After pretreatment, the inflow is subjected to a primary treatment including settling and floating to remove the settling and floating material. Subsequent to primary treatment, the wastewater is subjected to secondary treatment (also known as biological treatment) to remove soluble or dissolved organic matter by biodegradation, while suspended solids are Remove by slowly incorporating into a floc for biodegradation of solids. Subsequent to the secondary treatment, the wastewater is disinfected to kill pathogenic microorganisms and is usually sent to a tertiary treatment where explosion is performed again before draining.

  FIG. 2 illustrates another example of a wastewater treatment process. Specifically, this is an example of a pure oxygen explosion system. The pure oxygen explosion system is an improved method of the activated sludge process. The main difference is the method of supplying dissolved oxygen to the activated sludge. In other activated sludge processes, air is compressed and released below the surface of the water, creating an air-water interface, thereby moving oxygen into the water (dissolving oxygen). When compressed air is not used, a surface aerator agitates the water surface and sends air into the water to achieve oxygen transport. In a pure oxygen explosion system, the only substantial difference is that pure oxygen rather than air is released below the surface of the water, or is pumped into the water by a surface aerator and the aerator is covered. In this method, influent wastewater is subjected to primary clarification. As shown in FIG. 2, the influent wastewater is pretreated, then attached to the primary clarification tank, and then to the pure oxygen reactor and the secondary clarification tank. Waste water is brought into contact with chlorine and discharged to a water receiving tank. The sludge is returned to the pure oxygen reactor or combined with the concentrated sludge from the primary clarification tank and applied to the primary and secondary anaerobic digesters. The solid can then be dehydrated.

  Other wastewater treatment processes are known in the art and may be used according to the method of the present invention.

Wastewater Treatment Method In one embodiment, the present invention is a wastewater treatment method that reduces the amount of net sludge that is discarded and / or generated in this method.

  In this manner, a biofermentation system described in great detail in US Patent Publication No. 2003/0190742 (incorporated herein by reference) is installed on-site in a wastewater treatment facility. .

  An on-site system is a method of growing microorganisms at a site of contaminated wastewater and generally includes a main tank, a water inflow device, a treatment batch discharge device, a mixing device, and a temperature control device. An inoculum containing nutrients, water and microorganisms is sent to the on-site system. The inoculum grows in an on-site system to give a processed batch with an increased number of microorganisms. Then, at least a portion of the treatment batch containing the microorganism is used directly for contaminated wastewater, and the microorganism is not isolated, concentrated or lyophilized during the propagation and utilization steps. Microorganisms reduce pollutants in contaminated wastewater. In large activated sludge plants or single pass lagoons, holding tanks can be used for transport of process batches where process batches are large in volume for supply and input so that process batches can be discharged continuously. Diluted to

  Importantly, the use of an on-site bio-fermentation system allows for sufficient repeated inoculation of functional microorganisms (either external or internal), so that microbial communities are established early, undesirable resident groups, For example, filamentous fungi or Zoogloea type microorganisms that cause bulking can be eliminated. Solving problems such as filamentous fungi or zoo glare bulking, which can increase the total operating cost of wastewater treatment plants by as much as 20-25%, is a great market demand. The first processing cost increase arises from the need to use chemicals to clarify the water and concentrate the biomass in a sedimentation aid, or secondary clarifier. Examples of such chemicals include polymers, bentonite, alum or ferric salts. The second increase in processing costs is due to the growth of filamentous fungi and zoom glare, which reduces dehydration, increases the amount of equipment required to treat sludge and the amount of polymer for dehydration, thereby increasing costs. Arise. The third increase in processing cost is caused by an increase in manpower required due to inefficient operation, and an increase in transportation costs and fees for disposal. Biological fermentation systems provide a method used to control or eliminate unwanted microorganisms that cause bulking and sedimentation problems, such as filamentous fungi or zoom glare type microorganisms. The fermentation process reduces or eliminates the use of polymers to enhance sedimentation, minimizes the use of chemicals for dehydration, and the need for sludge treatment, manpower, transportation costs for disposal and Used to minimize fees.

In addition, the biofermentation process makes it possible to provide the desired microorganisms at an effective concentration sufficient to significantly treat the wastewater at the time of application. Optimally, the inoculum is about 10 ⁸ to 10 ⁹ cfu so that a minimum preferred inoculation of about 10 ³ to 10 ⁴ cfu / ml (colony forming units per milliliter) can be achieved at the time of application. Grows to a concentration of / ml.

  The type of microorganism present in the inoculum depends on the type of wastewater to be treated. The inoculum may contain single or multiple strains of microorganisms depending on the wastewater problem to be solved. The inoculum can be provided as a liquid or a dry product. The dried product is usually lyophilized or air dried. In addition, the microorganism may be derived from the outside, or the resident microorganism may be isolated from the wastewater during processing.

  The terms microorganism, microbe or organism, as used herein, are interchangeable and include fungi, yeast, bacteria and other small biodegradable single cell organisms.

  Preferably, sludge volume-reducing microorganisms (available for purchase from Advanced Biofermentation Services Inc, Fleming Island, Fla.) Have low BOD removal efficiency and system overload wastewater treatment facilities, and / or typically Used for wastewater treatment at treatment facilities that want to reduce the operational costs associated with sludge treatment, which accounts for about 40-50% of the operational costs.

Some examples of microorganisms are shown in Table 1 along with their inherent biodegradation characteristics.

  The determination of which culture or manufacturer's prescription is most effective for a particular wastewater can be made using standard respiration measurements. The principle of respirometry is to measure the activity of biomass exposed to the test substrate relative to a control containing the biomass and a known substrate for which the outcome is predictable. The substrate to be tested can range from a specific chemical or wastewater stream to a combined wastewater. As a representative example, it can be set to promote either an aerobic or anaerobic environment. Typical applications of respirometry are: treatment capacity of domestic and industrial wastewater; specific wastewater streams or chemical toxicity; chemical biodegradability; biochemical oxygen demand (BOD); and oxygen uptake rate Evaluation of (OUR).

  Aerobic microorganisms use oxygen for growth and metabolism of organic substrates. For aerobic microorganisms, the oxygen uptake rate (OUR) is directly related to the stability of organic matter and is therefore related to the ability to biodegrade organic wastewater.

  Respirometers and processing procedures for aerobic and anaerobic tests are available from US manufacturers such as Challenge Environmental Systems of Fayetteville (Arkansas); Arthur Technology of Funde du Bac; From the state). Examples of aerobic throughput tests include Whiteman, G. et al. R, TAPPI Environmental Conference "The Application of Selected Microbiological Formats in the Pulp and Paper Industry 1, TAPPI Environmental Proposals, B. 235-238, April 1991; Whiteman, G, R .; , Gwinnett industrial Conference "Optimizing Biological Processes-A Look Inside The Black Box", April 1995; and Whiteman, G., et al. R. , TAPPI Environmental Conference "Improving Treatment Performance with Natural Bioaugmentation", TAPPI Environmental Proceedings, Vancouver, BC, 1998, the disclosures of which are incorporated herein by reference.

  When the effects of individual isolates and / or preparations are compared using respiration measurements, the best inoculum for the fermentation process described herein can then be selected. Pre-prepared cultures were obtained from Advanced Biofermentation Services Inc. (Fleming Island, Florida).

  The term “nutrition” refers to the substrate required to help plants and organisms survive. The main nutrients are carbon, hydrogen, oxygen, sulfur, nitrogen and phosphorus. Nutrition includes both macronutrients and micronutrients. A typical composition of microorganisms is shown in Table 2. Here it is clear that different microorganisms have different compositions. Microorganisms also differ in their ability to assimilate nitrogen into amino acids and the basic components of proteins or ribonucleic acid (RNA) and deoxyribonucleic acid (DNA) purine or pyrimidine bases. Thus, different microorganisms have macronutrients (nitrogen and phosphorus) and micronutrients (eg magnesium, calcium, potassium, sodium, magnesium, cobalt, nickel, zinc, iron, chloride and sulfur to optimize the fermentation process ) Request is different. Information about macronutrients and micronutrients, including concentrations related to difficult-to-cultivate microorganisms, methods for determining whether specific micronutrients are needed, and explanation of the role of general nutrients by Introductory by Levy et al. See Microbiology, the disclosure of which is incorporated herein by reference.

  Active biomass composed primarily of bacteria in biological processing plants is 8-15% for most microorganisms, most typically 12-12.5% nitrogen, and 2-5%, most typically Contains 2.3 to 2.6% phosphorus. Phosphorus is important in forming adenosine triphosphate (ATP), a means by which microorganisms store energy.

Microorganisms are composed of proteins, carbohydrates, fats called lipids, or combinations of these substrates, and in particular, proteins are used to produce enzymes that are the basis of biodegradation processes. The biodegradation process for a particular organic substrate consists of a series of reactions. Certain enzymes cause individual reactions. These enzymes are composed of amino acids and optionally cofactors, usually metals that form the active site of the enzyme where the biodegradation and conversion of organic substrates takes place. Optimally, the micronutrient is present in an amount sufficient to optimize the fermentation or biodegradation process. Micronutrients include substrates such as vitamins, coenzymes, metals or inorganic compounds such as enzymes, coenzyme production or cofactors necessary for cell growth. For example, sulfur is required for assimilation of the essential amino acids, cysteine and methionine. Such micronutrients such as folic acid, pantothenic acid (coenzyme A), vitamin B ₁₂ (cobamide), biotin, nicotinic acid or nicotinamide (NAD), vitamin B ₁ (thiamine), vitamin B ₂ (riboflavin), vitamin B ₆ ( For information on coenzymes including pyridoxine), lipoic acid and ascorbic acid, see Biochemistry, Second Edition. Albert L. Lehninger, Worth Publishers Inc. , 1975, ISBN: 0-87901-047-9, and Levy et al., Introductory Microbiology John Wiley & Sons Inc. , 1973, ISBN 0-471-53155-3, the disclosures of which are incorporated herein by reference.

  As mentioned above, the type of microorganism used in the wastewater treatment process of the present invention depends on the type of wastewater problem to be solved. The most commonly used microorganisms are bacteria, most commonly aerobic mesophilic bacteria. Aerobic bacteria use oxygen to metabolize organic matter, which can be, for example, biochemical oxygen demand (BOD), chemical oxygen demand (COD), total organic carbon (TOC), or total carbon (TC). Measured by In addition, facultative bacteria that can be metabolized with or without oxygen, or anaerobic bacteria that do not use oxygen can be used. Bacteria are also classified with respect to the optimal temperature for their growth. Suitable temperatures are 55 to 75 ° C. for high heat; 30 to 45 ° C. for mesophilic; and 15 to 18 ° C. for refrigeration: uneven.

  As a result of the application or use of such on-site biofermentation processes and systems, the net sludge disposal and / or generation is reduced for both public and private wastewater treatment facilities.

  A preferred wastewater treatment procedure and process according to the present invention is schematically illustrated in FIGS. However, the method is not limited to any particular system described in the drawings or the detailed description above, and any apparatus that allows the practice of the present invention to be used instead.

  Referring to FIG. 3, wastewater treatment by the method of the present invention includes pretreatment, primary treatment (chemical and physical), secondary treatment (removed dissolved organic matter and suspended solids), tertiary treatment, sludge. Includes treatment, sludge disposal and liquid disposal.

  FIG. 4 shows specific treatment steps of the wastewater treatment method of the present invention.

  Pretreatment steps include screening and sand removal, conditioning and storage and oil separation. The chemical primary treatment includes at least two neutralization steps and chemical addition and agglomeration steps. Physical primary treatment includes multistage flotation, sedimentation and filtration steps. Secondary treatment of dissolved organic matter includes activated sludge, anaerobic lagoon, sprinkling filter bed, aerated lagoon, stabilized basin, rotating biocontact, membrane bioreactor, continuous batch reactor (SBR) and anaerobic contractor and filtration treatment including. Removal of suspended solids in the secondary process involves the use of an internal aeration basin (SBR) or membrane with a solids sedimentation or rest cycle. The wastewater is then subjected to tertiary treatment, which includes flocculation and sedimentation, filtration, carbon adsorption, ion exchange and membrane treatment. Sludge obtained from the treatment process can be used for sludge treatment. Specifically, sludge can be treated by digestion or wet combustion. Sludge can be concentrated (dehydrated) by gravity or buoyancy and reduced to a volume that is transported to an external disposal site. Sludge can also be treated by pressure filtration, vacuum filtration, centrifugation, lagoon or dry bed. Following the sludge treatment, the sludge can be discarded by incineration, ocean dumping and landfill. Treated diluted wastewater can also be disposed of by disposal into the water receiver, controlled or transported discharge, ocean dumping, surface spraying or groundwater infiltration, evaporation and incineration. Concentrated organic wastewater can be discarded by deep well injection or incineration.

  Surprisingly, the wastewater treatment process of the present invention incorporating an on-site biofermentation system that utilizes sludge volume-reducing microorganisms has reduced sludge disposal and / or generation.

  In particular, typically 0.5 pounds (lb) of sludge would be expected to be discarded and / or generated per pound (lb) of BOD processed by the secondary treatment. Based on the inflow BOD load by many biological systems and a typical BOD removal rate of 90%, this corresponds to 0.45 lb of sludge generated per 1 lb of BOD entering the plant.

  Biological sludge production rates vary with different wastewater constituents, for example fatty oils and / or grease (FOG) produce 0.7-0.8 lb sludge per lb reduced BOD, but like benzene or phenol Chemicals can be as low as 0.25 lb sludge per lb reduced BOD.

  However, when a biofermentation system using sludge volume reducing microorganisms as a treatment batch is introduced on-site into a wastewater treatment facility according to the method of the present invention, 0.125 lb per BOD 1 lb treated by the secondary system. Sludge is discarded and / or generated. Based on the inflow BOD load by many biological systems and a typical BOD removal rate of 90%, this corresponds to 0.112 pounds of sludge generated per 1 lb of BOD entering the plant and entering the treatment facility. Based on the amount, it will be significantly lower than expected by one skilled in the art.

  While not being bound by a particular mechanism, this low net sludge disposal and / or generation is present in the system, eg, as described in US Patent Publication No. 2003/0190742, and can be used in biological fermentation processes. This is thought to be due to an increase in the number of available microorganisms. Increasing the number of viable microorganisms in a biological system essentially reduces the F: M ratio, which means that more microorganisms survive with less food. That is, cell metabolism of microorganisms using BOD for cell maintenance rather than cell growth occurs. Therefore, the latter generates a low amount of biological sludge. In addition or alternatively, the reduction of filamentous microorganisms (in the activated sludge system) results in better settled sludge, allowing more sludge to be carried to the biological system, thereby reducing the F: M ratio. And the benefit of increased SRT is obtained. A decrease in F: M ratio and an increase in SRT are standard methods for reducing net sludge waste, as self-digestion proceeds in biological systems and net sludge waste is lower.

  Example 1

  Gray city

  The purpose of this study was to improve the efficiency and water treatment of BOD in Gray City's activated sludge wastewater treatment facility because the capacity per day of the conventional treatment system of Gray City is sometimes overloaded. It was to improve the processing capacity.

  Prior to treatment, Gray City is equipped with an integrated aerobic digester and four dry beds, a traditional comprehensive design designed to treat 400,000 gallons of domestic wastewater per day (gpd) Had an active sludge wastewater treatment system. Typically, the sludge was discarded to the dry bed after the first 90 days of normal operation before the winter visit.

  A model 250 biofermentation system, purchased from Advanced Biofermentation Services (Fleming Island, Florida) and introduced as described in US 2003/0190742, was installed on-site next to the activated sludge to be treated.

  Model 250 biofermentor, 30 gallons 1/4 strength processing batch per day, containing BOD-removing microorganisms under the trade name “Biobooster for BOD removal” which can be purchased from Advanced Biofermentation Services (Fleming Island, Florida) Set to supply. A full strength processing batch is defined as adding 10 pounds of bionutrient (nutrient used for microbial growth) to the biofermentor. Thus, a 1/4 strength processing batch is equivalent to its 1/4 or 2.5 pounds. Bionutrients used in this process can be purchased from Advanced Biofermentation Services (Fleming Island, Florida).

  The biofermentation process was initially set for 90 days before winter. Within 90 days from the start of treatment, significant improvements in the treatment process, including improved water throughput and better BOD removal without loss of TSS at discharge during peak flows (sometimes greater than 1 MGD), are Was observed. Such observations were made visually and by example by multiple operators.

  Surprisingly, in the spring of the following year, he noticed that there was no sludge to be disposed of on the dry floor, and the sludge disposal process attracted attention.

  A few months later, Gray City determined that there was a 75% reduction in sludge generation based on reduced use of dry beds. Gray City has already begun installing a new belt press and required $ 800,000 in construction costs to replace the dry floor. If Gray City recognized that biofermentation could reduce net sludge waste and / or generation, Gray City would not approve the expenditure.

  Importantly, Gray City noticed a 65% reduction in polymer usage and a 50% increase in water treatment capacity. Also, all foaming problems / antifoam use was eliminated. All of these result in improved wastewater treatment processes.

  Example 2

The Dublin City Wastewater Treatment Plant (WWTP) has used Alum for precipitation of suspended solids and associated BOD from the final effluent for the past eight years. The plant was a 4.0 MGD sprinkling filter plant with two traveling bridge sand filters at the end producing recycled water. This WWTP has three authorizations:
(B1) 4MGD, 30BOD, 30TSS
(B2) 4MGD, 25BOD, 15TSS
(B3) 6MGD, 25BOD, 30TSS

  In order to improve BOD removal, reduce the alum used in the secondary clarifier used for clarification, and develop a healthier biology to achieve the full capacity of the process, as described herein, The fermentation process was performed at WWTP in Dublin City.

  Specifically, a model 250 biological fermentation system, purchased from Advanced Biofermentation Services (Fleming Island, Florida) and introduced as described in US Patent Publication No. 2003/0190742, is located on-site next to the osmotic filtration system. installed. Model 250 is 1/60 gallons per day using a culture developed for sludge reduction called “Biobooster for sludge reduction” that can be purchased from Advanced Biofermentation Services (Fleming Island, Florida). It was set to supply a 4-strength processing batch.

  Treatment was carried out for 45 days.

  After 45 days using the biofermentation process, Dublin City eliminated the alum and saved about $ 100,000.

  Also, the algae growing on the rocks of the sprinkling filter flourished, the BOD emission was reduced, and the TSS met 85% removal without the use of alum. In addition, the decrease in the amount of biological sludge is conspicuous, and a press on the 5th of a week that generates two waste containers per day (each 20 yard roll-off type) results in one waste container per day (20 yard roll). Pressed once or twice a week resulting in an off-type).

  A biological fermentation system was permanently introduced.

  Notably, six months after operation, the press was once every two weeks. This means that the sludge treatment cost has been reduced by more than 70%. Digested sludge (including primary and secondary sludge) was also improved. Specifically, the digester sludge was changed from 1.5% solids to 3% solids, and the supernatant of the digester became transparent.

  Example 3 (forecast)

  Method for improving anaerobic sludge digestion

  Another application recognized from the surprising results in Dublin is the potential for improved anaerobic sludge digestion.

  For the treatment of anaerobic digester sludge, a biofermentor (purchased from Advanced Biofermentation Services (Fleming Island, FL)) is installed on-site in the digester to add the treatment batch directly to the digester. The input speed can vary depending on the volume of the digester. Typically, however, in digesters below 1 MGV, the input rate is 10-60 gallons per day for 1 / 4-1 / 2 strength batches.

  In order to achieve a faster metabolic rate, the input rate is doubled or quadrupled to achieve the desired result.

  The cost benefit to the customer depends on improving the quality of the digester supernatant and on the solids concentration that aids dehydration and thus lowers the chemical / polymer costs for dehydration. In addition, operational costs will depend on reduced manpower and reduced frequency of disposal. Furthermore, it improves the efficiency of the anaerobic digester that limits its digestion capacity, thereby avoiding capital investment and minimizing the necessary expenses.

  Example 4 (forecast)

  Method for improving sludge digestion in a regulating pond.

  Another application recognized from the surprising results in Gray is the potential for improved sludge digestion in conditioned ponds typically used in many small towns prior to treatment in a comprehensive plant. Also, expensive pretreatment and / or first clarification tanks can be avoided.

  For the treatment of conditioned sludge, a biological fermenter (purchased from Advanced Biofermentation Services (Fleming Island, Florida)) is installed on-site in the conditioned pond to add treatment batches directly to the conditioned pond at the wastewater plant inlet. To do.

  The input speed will depend on the volume or inflow volume of the regulating pond. Typically, however, an inflow of less than 1 to 3 MGV would be 10 to 60 gallons per day for a 1/4 to 1/2 strength batch. Scale-up to a larger plant will be proportional. In order to achieve a faster metabolic rate, the input rate is doubled or quadrupled to achieve the desired result.

  The cost benefit to the customer will depend on improved BOD removal in the pond and the reduction of solids that allows the avoidance or delay of the need for solid dredging. The soot is very expensive as it requires the cost of dehydrating equipment, chemicals / polymers for dehydration, manpower, transportation and disposal costs. Furthermore, it improves the efficiency of the adjustment capability that limits its capabilities, thereby avoiding capital expenditure and minimizing the necessary expenses.

  Example 5 (Forecast)

  Reduction method of primary sludge in the first clarification tank before the anaerobic digestion tank

  Another application recognized from the surprising results in Dublin is the possibility of reducing the primary sludge in the first clarifier before the anaerobic digester because the treatment of the primary sludge is very expensive. right.

  For the treatment of the first clarifier sludge, a biological fermenter (purchased from Advanced Biofermentation Services (Fleming Island, Florida)) was turned on to add the treatment batch directly to the first clarifier sludge at the wastewater plant inlet. Install at the site.

  The input rate can vary depending on the capacity being processed by the wastewater treatment plant. Typically, however, the processing capacity with a drainage plant of less than 1 to 3 MGV will be a 10 to 60 gallon 1/4 to 1/2 strength batch per day. Scale-up to a larger plant will be proportional. In order to achieve a faster metabolic rate, the input rate is doubled or quadrupled to achieve the desired result.

  Cost benefits to customers will depend on reduced sludge treatment costs for primary sludge, eg reduced costs for dewatering equipment, chemicals / polymers for dewatering, manpower, transportation and disposal costs. In addition, a second advantage is to improve the efficiency of the sludge treatment process that limits its capacity, thereby avoiding capital investment and minimizing the necessary expenses.

  All patents, patent applications, provisional applications and publications mentioned or cited herein, including all drawings and tables thereof, to the extent that they do not correspond to the clear teachings of this specification, are all cited. Are incorporated herein by reference.

  While various embodiments of the present invention have been described, it will be apparent to those skilled in the art that many more embodiments and embodiments are possible within the scope of the present invention. Accordingly, the invention is not to be restricted except in light of the claims and their equivalents.

The present invention relates to an improvement in sludge removal and a method for maintaining the quality of discharged water. The method directs an influent wastewater stream to a treatment facility, wherein the influent wastewater stream is at a flow rate of at least 20,000 gallons (75,708 L) per day and the influent wastewater stream is at least 50 mg / L solids and 100 mg / L BOD; at the treatment facility, the solids and BOD are removed from the influent wastewater stream to obtain a final outlet stream: where the final outlet stream is 10% of the wastewater stream Having less than 10% solids and BOD less than 10% of the wastewater stream; including removing solids and BOD yields less than about 0.25 kg of secondary sludge per kg of removed BOD. In this method, the influent wastewater stream may have at least about 100 mg / L solids and 200 mg / L BOD, and the removed solids are less than about 0.25 kg secondary per kg removed BOD. Sludge may be used. In this way, the inflow wastewater stream may have a BOD of solids and 400 mg / L of at least about 100 mg / L, removal solids removed BOD 1 kg per second of less than about 0.25 kg Sludge may be used. In this way, the inflow wastewater stream may have a BOD of solids and 100 mg / L of at least about 50 mg / L, removal solids removed BOD 1 kg per second of less than about 0.125 kg Sludge may be used. In this method, the incoming wastewater stream may have at least about 100 mg L solids and 200 mg / L BOD, and the removed solids are less than about 0.125 kg secondary sludge per kg removed BOD. There may be.

In another embodiment, the invention relates to a method for improving sludge removal and maintaining effluent quality. The method directs an influent wastewater stream to a treatment facility, wherein the influent wastewater stream is at a flow rate of at least 20,000 gallons (75,708 L) per day and the influent wastewater stream is at least 50 mg / day L solids and 100 mg / L BOD; at the treatment facility, solids and BOD are removed from the incoming wastewater stream to obtain a final discharge stream: where the final discharge stream is 10% of the wastewater stream Having less than 10% solids and a BOD of less than 10% of the wastewater stream; including removing solids and BOD yields less than about 0.25 kg of biological sludge per kg of removed BOD. In this method, the influent wastewater stream may have at least about 100 mg / L solids and 200 mg L BOD, and the removed solids were less than about 0.25 kg biological sludge per kg removed BOD. May be. In this method, the influent wastewater stream may have at least about 100 mg L solids and 400 mg / L BOD, and the removed solids were less than about 0.25 kg biological sludge per kg removed BOD. May be. In this method, the influent wastewater stream may have at least about 50 mg / L solids and 100 mg / L BOD, the removed solids being less than about 0.125 kg biosludge per kg removed BOD. It may be. In this method, the incoming wastewater stream may have at least about 100 mg / L solids and 200 mg / L BOD, and the removed solids are less than about 0.125 kg biosludge per kg removed BOD. It may be.

In another embodiment, the invention relates to a method for improving sludge removal and maintaining effluent quality. The method directs an influent wastewater stream to a treatment facility, wherein the influent wastewater stream is at a flow rate of at least 20,000 gallons (75,708 L) per day and the influent wastewater stream is at least 50 mg / day L solids and 100 mg / L BOD; at the treatment facility, the solids and BOD are removed from the incoming wastewater stream to obtain a first final discharge stream: wherein the first final discharge stream Has a solids content of less than 10% of the wastewater stream and a BOD of less than 10% of the wastewater stream; the wastewater stream is treated by adding a treatment batch from the biofermentor, and thereby in the final effluent stream Reducing the weight of the removed sludge by at least about 10% without increasing solids and BOD. In this way, the processing batch can be added to an anaerobic digester, a conditioning pond and / or a primary clarifier. In this way, the weight of the removed sludge can be reduced by at least about 25% without increasing the solids and BOD in the final discharge stream. In this way, the weight of the removed sludge can be reduced by at least about 50% without increasing the solids and BOD in the final discharge stream.

In yet another embodiment, the present invention relates to a method for improving sludge removal and maintaining effluent quality. The method directs an influent wastewater stream to a treatment facility, wherein the influent wastewater stream is at a flow rate of at least 20,000 gallons (75,708 L) per day and the influent wastewater stream is at least 50 mg / day L biosolids and 100 mg / L BOD; at the treatment facility, the biosolids and BOD are removed from the influent wastewater stream to obtain a final effluent stream: where the final effluent stream is 10% of the wastewater stream With less than 10% biosolids and less than 10% BOD of the wastewater stream; including removing solids and BOD yields less than about 0.25 kg biosolids per kg removed BOD. In this method, the sludge may be primary sludge, biological sludge, and / or the sludge may include primary sludge and biological sludge. In this method, the incoming wastewater stream may have at least about 100 mg / L solids and 200 mg / L BOD, wherein the removed solids are less than about 0.25 kg biosolids per kg removed BOD. It may be. In this method, the influent wastewater stream may have at least about 100 mg / L solids and 400 mg / L BOD, wherein the removed solids are less than about 0.25 kg biosolids per kg removed BOD. It may be. In this method, the influent wastewater stream may have at least about 50 mg L solids and 100 mg / L BOD, and the removed solids were less than about 0.125 kg biosolids per kg removed BOD. May be. In this method, the influent wastewater stream may have at least about 100 mg / L solids and 200 mg / L BOD, wherein the removed solids are less than about 0.125 kg biosolids per kg removed BOD. It may be.

In a further embodiment, the invention relates to a method for improving sludge removal and maintaining effluent quality. The method directs an influent wastewater stream to a treatment facility, wherein the influent wastewater stream is at a flow rate of at least 20,000 gallons (75,708 L) per day and the influent wastewater stream is at least 50 mg / day L solids and 100 mg / L BOD; at the treatment facility, solids and BOD are removed from the incoming wastewater stream to obtain a final discharge stream: where the final discharge stream is 10% of the wastewater stream Having less than 10% solids and BOD less than 10% of the wastewater stream; including removing solids and BOD yields less than about 0.25 kg of secondary sludge per kg of removed BOD. In this method, the incoming wastewater stream may have at least about 100 mg / L solids and 200 mg L BOD, and the removed solids are less than about 0.25 kg secondary sludge per kg removed BOD. There may be. In this way, the inflow wastewater stream may have a BOD of solids and 400 mg / L of at least about 100 mg / L, removal solids removed BOD 1 kg per second of less than about 0.25 kg Sludge may be used. In this method, the incoming wastewater stream may be at least about 50 mg / L solids and 100 mg L BOD, and the removed solids are less than about 0.125 kg secondary sludge per kg removed BOD. Also good. In this method, the influent wastewater stream may have at least about 100 mg / L solids and 200 mg / L BOD, wherein the removed solids are less than about 0.125 kg secondary per kg removed BOD. Sludge may be used.

In yet another embodiment, the present invention relates to a method for improving sludge removal and maintaining effluent quality. The method directs an influent wastewater stream to a treatment facility, wherein the influent wastewater stream is at a flow rate of at least 20,000 gallons (75,708 L) per day and the influent wastewater stream is at least 50 mg / day L solids and 100 mg / L BOD; at the treatment facility, solids and BOD are removed from the influent wastewater stream to a final effluent stream: where the final effluent stream is 10% of the wastewater stream Having less than 10% solids and a BOD of less than 10% of the wastewater stream; including removing solids and BOD yields less than about 0.25 kg of biological sludge per kg of removed BOD. In this method, the influent wastewater stream may have at least about 100 mg / L solids and 200 mg L BOD, and the removed solids were less than about 0.25 kg biological sludge per kg removed BOD. May be. In this method, the influent wastewater stream may have at least about 100 mg / L solids and 400 mg / L BOD, and the removed solids are less than about 0.25 kg biological sludge per kg removed BOD. It may be. In this method, the influent wastewater stream may have at least about 50 mg / L solids and 100 mg / L BOD, the removed solids being less than about 0.125 kg biosludge per kg removed BOD. It may be. In this method, the incoming wastewater stream may have at least about 100 mg / L solids and 200 mg / L BOD, and the removed solids are less than about 0.125 kg biosludge per kg removed BOD. It may be.

Specifically, typically, BOD 1 kg per processed by secondary treatment will 0.5 kg of sludge is expected to disposal and / or generated. Based on the inflow BOD load by many biological systems and a typical BOD removal rate of 90%, this corresponds to 0.45 kg of sludge generated per kg of BOD entering the plant.

Biological sludge production rates vary with different wastewater constituents, for example fatty oils and / or grease (FOG) produce 0.7-0.8 kg sludge per kg BOD reduction, but with benzene or phenol Such chemicals can be as low as 0.25 kg sludge per kg BOD reduction.

However, when a biological fermentation system using sludge-reducing microorganisms as a processing batch is introduced on-site into a wastewater treatment facility according to the method of the present invention, 0.125 per kg of BOD processed by the secondary system. kg of sludge is discarded and / or generated. Based on the inflow BOD load by many biological systems and a typical BOD removal rate of 90%, this corresponds to 0.112 kg of sludge generated per kg of BOD entering the plant and entering the treatment facility Based on the amount to be achieved, it will be significantly lower than expected by those skilled in the art.

Prior to treatment, Gray City was designed to treat 400,000 gallons (1,514,165L) of domestic wastewater per day with an integrated aerobic digester and four dry beds. It had a traditional comprehensive activated sludge wastewater treatment system. Typically, the sludge was discarded to the dry bed after the first 90 days of normal operation before the winter visit.

Model 250 biofermentor contains 30 gallons (114 L) of ¼ strength per day containing BOD-removing microorganisms under the trade name “Biobooster for BOD removal” that can be purchased from Advanced Biofermentation Services (Fleming Island, Florida ) The process batch was set to be fed. A full strength treated batch is defined as adding 10 pounds (4,536 g) of bionutrient (nutrient used for microbial growth) to the biofermentor. Thus, a 1/4 strength processing batch is equivalent to its 1/4 or 2.5 pounds (1134 g) . Bionutrients used in this process can be purchased from Advanced Biofermentation Services (Fleming Island, Florida).

Specifically, a model 250 biological fermentation system, purchased from Advanced Biofermentation Services (Fleming Island, Florida) and introduced as described in US Patent Publication No. 2003/0190742, is located on-site next to the osmotic filtration system. installed. Model 250 is 60 gallons (227 L) per day using a culture developed for sludge reduction called “Biobooster for sludge reduction” that can be purchased from Advanced Biofermentation Services (Fleming Island, Florida ). Was set to supply a quarter-strength processing batch.

Also, the algae growing on the rocks of the sprinkling filter flourished, the BOD emission was reduced, and the TSS met 85% removal without the use of alum. In addition, the decrease in the amount of biological sludge is conspicuous, and the press on the 5th of the week that generates two waste containers per day (each 20 yards (18.3m) roll-off type) is one waste container per day. (20 yard (18.3 m) roll-off mold) resulting in 1 or 2 presses per week.

For the treatment of anaerobic digester sludge, a biofermentor (purchased from Advanced Biofermentation Services (Fleming Island, FL)) is installed on-site in the digester to add the treatment batch directly to the digester. The input speed can vary depending on the volume of the digester. Typically, however, in digesters below 1 MGV, the input rate is 10-60 gallons (37.9-227 L) per quarter-1 / 2 strength batch per day.

The input speed will depend on the volume or inflow volume of the regulating pond. Typically, however, an inflow of less than 1 to 3 MGV would be 10 to 60 gallons (37.9 to 227 L) of a 1/4 to 1/2 strength batch per day. Scale-up to a larger plant will be proportional. In order to achieve a faster metabolic rate, the input rate is doubled or quadrupled to achieve the desired result.

The input rate can vary depending on the capacity being processed by the wastewater treatment plant. Typically, however, the processing capacity with a drainage plant of less than 1 to 3 MGV will be a 10 to 60 gallon (37.9 to 227 L) quarter to 1/2 strength batch per day. Scale-up to a larger plant will be proportional. In order to achieve a faster metabolic rate, the input rate is doubled or quadrupled to achieve the desired result.

Claims (34)

Methods for improving sludge removal and maintaining effluent quality:
Directing an influent wastewater stream to a treatment facility; wherein the influent wastewater stream is at a flow rate of at least 20,000 gallons per day, the influent wastewater stream being at least 50 mg / L solids and 100 mg / L Having a BOD of
In a treatment facility, solids and BOD are removed from the incoming wastewater stream to obtain a final discharge stream; where the final discharge stream is less than 10% solids of the wastewater stream and less than 10% BOD of the wastewater stream Having:
Removing solids and BOD to produce less than about 0.25 pounds of secondary sludge per pound of removed BOD.   The influent wastewater stream has at least about 100 mg / L solids and 200 mg / L BOD, and the removed solids are less than about 0.25 pounds of secondary sludge per pound of removed BOD. the method of.   The influent wastewater stream has at least about 100 mg / L solids and 400 mg / L BOD, and the removed solids is less than about 0.25 pounds of secondary sludge per pound of removed BOD. the method of.   The influent wastewater stream has at least about 50 mg / L solids and 100 mg / L BOD, and the removed solids is less than about 0.125 pounds of secondary sludge per pound of removed BOD. the method of.   The influent wastewater stream has at least about 100 mg / L solids and 200 mg / L BOD, and the removed solids is less than about 0.125 pounds of secondary sludge per pound of removed BOD. the method of. Methods for removing sludge and maintaining discharged water quality:
Directing the influent wastewater stream to a treatment facility; wherein the influent wastewater stream is at a flow rate of at least 20,000 gallons per day and the influent wastewater stream is at least 50 mg / L solids and 100 mg / L Have a BOD;
At the treatment facility, solids and BOD are removed from the incoming wastewater stream to obtain a final discharge stream; wherein the final discharge stream is less than 10% solids and less than 10% of the wastewater stream Have a BOD;
Removing solids and BOD to produce less than about 0.25 pounds of biological sludge per pound of removed BOD.   The influent wastewater stream has at least about 100 mg / L solids and 200 mg / L BOD, and the removed solids are less than about 0.25 pounds of biological sludge per pound of removed BOD. Method.   The influent wastewater stream has at least about 100 mg / L solids and 400 mg / L BOD, and the removed solids are less than about 0.25 pounds of biological sludge per pound of removed BOD. Method.   The method of claim 6, wherein the influent wastewater stream has at least about 50 mg L solids and 100 mg / L BOD, and the removed solids are less than about 0.125 pounds of biosludge per pound of removed BOD.   7. The method of claim 6, wherein the incoming wastewater stream has at least about 100 mg / L solids and 200 mgL BOD, and the removed solids is less than about 0.125 pounds of biosludge per pound of removed BOD. Methods for removing sludge and maintaining discharged water quality:
Directing the influent wastewater stream to a treatment facility; wherein the influent wastewater stream is at a flow rate of at least 20,000 gallons per day and the influent wastewater stream is at least 50 mg / L solids and 100 mg / L Have a BOD;
At the treatment facility, solids and BOD are removed from the incoming wastewater stream to obtain a first final discharge stream; wherein the first final discharge stream is less than 10% solids and wastewater of the wastewater stream Having a BOD of less than 10% of the stream;
Treating the effluent stream by adding a treatment batch from the biofermentor, thereby reducing the weight of the removed sludge by at least about 10% without increasing the solids and BOD in the final effluent stream. Including methods.   The method of claim 11, wherein the treatment batch is added to an anaerobic digester.   The method of claim 11, wherein the processing batch is added to a conditioning pond.   The method of claim 11, wherein the processing batch is added to the first clarification tank.   12. The method of claim 11, wherein the weight of the removed sludge is reduced by at least about 25% without increasing solids and BOD in the final effluent stream.   12. The method of claim 11, wherein the weight of the removed sludge is reduced by at least about 50% without increasing solids and BOD in the final effluent. Methods for removing sludge and maintaining discharged water quality:
Directing the influent wastewater stream to a treatment facility; wherein the influent wastewater stream is at a flow rate of at least 20,000 gallons per day and the influent wastewater stream is at least 50 mg / L biosolids and 100 mg / L Have a BOD;
In a treatment facility, biosolids and BOD are removed from the incoming wastewater stream to obtain a final discharge stream; wherein the final discharge stream is less than 10% of the biosolids and wastewater stream of the wastewater stream Have a BOD;
Removing solids and BODs to produce less than about 0.25 pounds of biosolids per pound of removed BOD.   The method according to claim 17, wherein the sludge is primary sludge.   The method of claim 17, wherein the sludge is biological sludge.   The method of claim 17, wherein the sludge comprises primary sludge and biological sludge.   18. The method of claim 17, wherein the incoming wastewater stream has at least about 100 mg / L solids and 200 mg L BOD, and the removed solids are less than about 0.25 pounds of biosolids per pound of removed BOD.   18. The incoming wastewater stream has at least about 100 mg / L solids and 400 mg / L BOD, and the removed solids are less than about 0.25 pounds of biosolids per pound of removed BOD. Method.   18. The method of claim 17, wherein the incoming wastewater stream has at least about 50 mg L solids and 100 mg / L BOD, and the removed solids are less than about 0.125 pound biosolids per pound removed BOD.   18. The influent wastewater stream has at least about 100 mg / L solids and 200 mg / L BOD, and the removed solids are less than about 0.125 pounds of biosolids per pound of removed BOD. Method. Methods for removing sludge and maintaining discharged water quality:
Directing the influent wastewater stream to a treatment facility; wherein the influent wastewater stream is at a flow rate of at least 20,000 gallons per day and the influent wastewater stream is at least 50 mg / L solids and 100 mg / L Have a BOD;
At the treatment facility, solids and BOD are removed from the incoming wastewater stream to obtain a final discharge stream; wherein the final discharge stream is less than 10% solids and less than 10% of the wastewater stream Have a BOD;
Removing solids and BOD to produce less than about 0.25 pounds of secondary sludge per pound of removed BOD.   26. The influent wastewater stream has at least about 100 mg / L solids and 200 mg / L BOD, and the removed solids are less than about 0.25 pounds of secondary sludge per pound of removed BOD. the method of.   26. The influent wastewater stream has at least about 100 mg / L solids and 400 mg / L BOD, and the removed solids are less than about 0.25 pounds of secondary sludge per pound of removed BOD. the method of.   26. The influent wastewater stream has at least about 50 mg / L solids and 100 mg / L BOD, and the removed solids are less than about 0.125 pounds of secondary sludge per pound of removed BOD. the method of.   26. The method of claim 25, wherein the incoming wastewater stream has at least about 100 mg L solids and 200 mg / L BOD, and the removed solids is less than about 0.125 pounds of secondary sludge per pound of removed BOD. . Methods for removing sludge and maintaining discharged water quality:
Directing the influent wastewater stream to a treatment facility; wherein the influent wastewater stream is at a flow rate of at least 20,000 gallons per day and the influent wastewater stream is at least 50 mg / L solids and 100 mg / L Have a BOD;
In a treatment facility, solids and BOD are removed from the incoming wastewater stream to a final discharge stream; where the final discharge stream is less than 10% solids and less than 10% of the wastewater stream Have a BOD;
Removing solids and BOD to produce less than about 0.25 pounds of biological sludge per pound of removed BOD.   31. The influent wastewater stream having at least about 100 mg / L solids and 200 mg / L BOD, wherein the removed solids is less than about 0.25 pounds of biosludge per pound of removed BOD. Method.   31. The influent wastewater stream having at least about 100 mg / L solids and 400 mg / L BOD, and the removed solids is less than about 0.25 pounds of biosludge per pound of removed BOD. Method.   31. The influent wastewater stream having at least about 50 mg / L solids and a BOD of 100 mg / L, wherein the removed solids is less than about 0.125 pounds of biosludge per pound of removed BOD. Method.   31. The inflow waste stream has at least about 100 mg / L solids and 200 mg / L BOD, and the removed solids are less than about 0.125 pounds of biosludge per pound of removed BOD. Method.

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