STANDARDS FOR AEROBIC AERATION SYSTEMS FOR THE BIOREMEDIATION OF DAIRY WASTE STREAMS AND OTHER RELATED WASTE STREAMS. This document gives an overview of aerobic and anaerobic bioremediation technology treating dairy and other related waste streams. To date the only system with proven results and back up data with complete water analysis reports is the WaterPure-Keeton Specific Design System. The Waterpure-Keeton Specific Design System is designed by aqua engineers and aquaculture engineers with approved engineering in diff-user aeration, microbial digestion, and wastewater engineering. The biological additives for a WaterPure-Keeton System requires a biologist and microbiologist with expertise in microbial formulation, dosing techniques and treatment of organic wastes. The principles of WaterPure Technology have over thirty years experience with aerobic systems, waste digestion and waste stream conversion to an enriched plant food effluent and odor control. The WaterPure-Keeton Aerobic Specific Design System, is explained detail in this document with examples of the quarterly water analysis reports of the incoming and outgo affluent. It is the goal of WaterPure Technology to be the leader and set standards for the bioremedition technology for the dairy industry and other related waste streams. WaterPure Technology
Overview of aerobic and anaerobic bioremediation technology for treating Anaerobic animal waste treatments systems are generally characterized by systems with liners or covered lagoons designed to mitigate smell and odor problems or more advanced treatments including large biogas digesters to reduce dairy waste. Anaerobic processes are very slow at best and do not readily digest the amount of waste produced by large dairies, unless very large and expensive digestors and associated equipment is installed. These systems must be designed to either burn the biogas, produce electricity, or designed to utilize the energy produced in the burning process for heating the facility. Anaerobic digestion relies on microbial decomposition reactions and processes that break down wastes with nooxygen present. This anaerobic process in very slow and cannot treat theamount of waste without the benefit of specialized, complex, and expensive equipment. Covering lagoons to collect the gasses produced is only a band-aide solution and does not address solid waste disposal problems and water quality problems associated with the use of the remaining solution on crops. Problems Associated With Open Dairy Waste Lagoons or Covered Animals Waste Lagoons:
Aerobic Systems A properly designed lagoon aeration specification should describe an automatic lagoon animal waste aerobic aeration system. Components of the system should consist of high pressure (greater than 200 inches water pressure) regenerative air blowers, electrical controls, cooling manifold, pressure relief valve, system controls, flow meters, gauges, self weighted air-feeder tubing, duraplate air diffusion system, pipe manifolds, valves, fitting and all other materials necessary for a "knockdown " (turnkey) aeration system. Aerobic systems vary greatly in the design and efficiency of the system. In general creating and maintaining aerobic, highly oxygenated, conditions in the digestion ponds is the goal of any aerobic system. The design must include continuous transfer of excess oxygen to the lagoon along with continuous mixing of the lagoon manure suspension. For proper operation of the aerobic system, a mixture of specialized aerobic and facultative anaerobic microbes must be used to inoculate the waste lagoons on at least a bi-weekly basis to maintain proper digestion. The pH, electrical conductivity (Ecw), and total alkalinity must be taken on a biweekly basis. The Water Pure-Keeton Aerobic Dairy Lagoon Treatment ProcessThis tested and proven process and system may be used as a standard for the industry The combined over thirty years experience with aerobic systems and recent specific research on dairy waste digestion and odor control may serve the dairy industry and the states in which the dairies reside. The overall reduction of B.0.D. and reduction in nutrients and salts in the processed water can serve to greatly reduce the possibility of future ground water contamination from modem dairy operations. The following are some of the observed results of two years of testing and application of the Water Pure-Keeton Aerobic Dairy Lagoon Treatment Process.
Water Pure-Keeton Aerobic Treatment Process System Design and Specifications The pond design for these systems should include a minimum of three ponds: A minimum of 15-day retention time is required in the first pond for a proper initial aerobic digestion of dairy waste stream materials. The size of the ponds must be determined for each facility associated with the flush lane outflow rate, number of animals, expected solids and B.O.D (biological oxygen demand) . The subsequent ponds should be properly aerated to maintain the aerobic digestion and to minimize odors. The three pond process can remove 95% of total B.O.D. utilizing the WaterPure-Keeton treatment system. In layman's terms a 95% reduction in overall biological oxygen demand means that 95 percent of the total waste has been reduced or converted into a more environmentally friendly form. The depth of the ponds must be a minimum of 15 feet and a maximum of 20 feet. The depth is critical for proper agitation, oxygen transfer efficiency, and proper mixing in the retention ponds. The shape of the ponds is critical for the efficiency of the digestion process. Water Pure Technologies provides design specifications for new ponds and design help to maximize the efficiency of existing operations. Ideally a system will start with clean ponds rather than attempting to retrofit existing ponds. Though good success is observed in retrofit systems, playing catch-up on the solids in the ponds as new waste material is added each day requires that the system be oversized which can increase the cost of the system. The air system must provide a minimum of 2.5 pound of oxygen for each pound of BOD inflow to the digestion ponds. Specialized WaterPure-Keeton Aerobic and Facultative Anaerobic microbes are used to inoculate the waste lagoons on a biweekly basis. When the inoculation regiment of the ponds is properly maintained, the total amount of oxygen needed to provide proper digestion may be greatly reduced. In these treatment situations, with and without separators, it is critical to build a subsurface grid of self-cleaning distribution units that are specifically designed to produce extremely small sized air bubbles properly placed to provide the efficient aeration and mixing of the pond. Each WaterPure-Keeton subsurface aeration unit is designed to circulate up to 2,500 gallon per minute of water to the surface of the ponds while at the same time adding oxygen to the effluent water. The airlift principal is very important in moving large volumes of water to the pond surface with extreme efficiency. The airlift principal provides major oxygen exchange at the air water interface as the water with lower dissolved oxygen is repeatedly moved to and exposed to the surface. Each WaterPure-Keeton subsurface aeration unit is designed to produce laminar flow and best oxygen transfer rate efficiency at 2.5 cubic feet per minute design airflow. Recirculation of water from the bottom up is essential to prevent anaerobic conditions from developing which promote rapid microbial decomposition when the correct microbes are added on a biweekly basis. These units are designed to be retrievable if maintenance is required but are essentially nonclogging. An oxygen transfer rate efficiency of 25-28 % is achieved at a depth of 14 feet and appreciably greater efficiency is observed at depths from 15-20 feet. The key to the Aerobic WaterPure-Keeton process requires treatment lagoons to be completely vertically mixed by our WaterPure-Keeton subsurface aeration unit (Duraplate) bottom aeration devices. This process of vertical mixing does not allow the waste to accumulate or to remain on the bottom and become anaerobic. Microbial digestion finishes the solid waste decomposition. As soon as any lagoon is allowed to become anaerobic, the rapid digestion process essentially stops. The BOD reduction and the denitrification processes that are integral to the success of the Water Pure Technologies digestion process must be monitored for efficiency. Any interruption in aeration or the inoculation process may retard the digestion process. In the case of digestion ponds fed from unseparated flush-lanes, it may be necessary to provide additional directed surface aeration to minimize low-density solids from building on the surface of the ponds. If these solids were allowed to build the solids may be raised above the surface of the pond liquid, and the digestion of the solids would become much less efficient or even stop completely. The mixing of any floating solids back into the pond suspension is necessary for the process to remain efficient and guides the solids back into the mixing stream of the subsurface diffusers. Surface aerators may be required to remix the solids back into the digestion solution. The WaterPure-Keeton lagoon aeration specification describes an automatic lagoon animal waste aerobic aeration system. Components of the system consist of high pressure (greater than 200 inches water pressure) regenerative air blower, electrical controls, cooling manifold, pressure relief valve, system controls, flow meters, gauges, self weighted air-feeder tubing, duraplate air diffusion system, pipe manifolds, valves, fitting and all other materials necessary for a "knockdown " (turnkey) aeration system. System must be designed by an aqua engineer, aquaculture engineer or approved engineer with diffuser aeration, microbial digestion and wastewater engineering background. Other biological requirements for system design stipulate a biologist or microbiologist with expertise in microbial formulation, dosing techniques and treatment of organic wastes. Each WaterPure-Keeton system must be specifically engineered and designed to meet the site-specific conditions and biological parameters for each dairy and based upon the biological parameters necessary to achieve an average of 90% reduction in biological oxygen demand and reduction of other water quality parameters as outlined in this document. The turnkey onshore air system is designed to produce high volume low-pressure air and deliver air via a pressurized manifold to various valved manifold locations. The air is then carried via specialized "heavy set" non-leaded self-sinking flexible tubing, (Keeton weighted feeder tubing). This weighted tubing delivers air to each Duraplate flexible membrane diffuser that are spaced according to design parameters for uniform water mixing and oxygen diffusion throughout the complete pond. The flush lane water and the outflow water from both the first pond and the irrigation storage pond must have the following parameters tested quarterly. Both the inorganic and organic parameters must be tested so that the water quality may be documented for long-term usability on crops. A record of both the bio-load and saft concentration of the outflow water used for irrigation must be maintained. The testing should include the evaluation of nitrogen compounds in the irrigation water as well as the phosphorus and potassium ion concentrations in the outflow water. These records will allow the long-term evaluation of the dairy water when used on crops and allow the farming operations using this processed water to decrease the other fertilizers added to their crops. Sampling also provides a record of the degree of water quality treatment, insures the proper functioning of the system and will be important in the future to meet discharge water quality requirements. Water Pure Technologies list of variables currently being tested and documented on both the flush-lane solution product water to be used for irrigation: At the time of inoculation, at least twice a week, the following variables must be field-tested and proper records maintained on the flush-lane solution and the stored water that is to be used for irrigation. Independent Laboratory Testing
The independent laboratory testing of both the flush-lane inflow water and the product water used for irrigation should be completed at least quarterly. This will allow verification of the quality of the product water and evaluation of the efficiency of the aerobic digestion system. Records must be maintained to allow verification of the water nutrient load to be documented on product water used for irrigation. The Water Pure Technologies (WPT) standards for variables to be regularly tested are listed below. Many of the standards set by WaterPure-Keeton are not required by existing programs, however these variables are useful in the evaluation and long term use of the product water for irrigation. In the future dairy waste strewn water used for irrigation must be documented for nutrient load. This is part of programs now being initiated by the University of California Cooperative Extension with funding from the USDA CSREES Water Quality Program. The program is an attempt to minimize any over application of fertilizers applied to farming operations. This program requires the nutrient load of the water from waste stream ponds used on crops to be included in any crop nutrient programs. Because the water is used on fields near the dairy to both produce silage crops for use on the dairy and also on other farming operations, the documentation of the quality of the product water is critical to the long-term use of this water. The reports are produced quarterly for the dairies along with the actual testing data. The staff of Water Pure Technologies has completed the short course, Using Dairy Lagoon Water for Crop Production, conducted by the University of California Cooperative Extension Service in February 2000. The data that WaterPure Technologies has documented and will continue to collect for the dairies and for farming operations will serve to establish a database that will be useful to the industry in minimizing the over application of commercial fertilizers. The information associated with the irrigation water used from the dairy waste lagoons will help to insure the long-term safe operation of the dairies. The database will allow any changes in nutrient load to be noted and be part of the information made available to the farming operations near the dairy utilizing the product water for irrigation. The farming operations can use this data to regulate any commercial fertilizers needed to produce their crops. This can result in savings to the farmer and minimize the chance of problems occurring because of excess fertilizer applications. If commercial fertilizer applications are made knowing the total nutrients available in the product water, the ground water table will be safeguarded from nutrient contamination. The standards set by Water Pure Technologies for the testing and record keeping could provide a universal set of standards and a database which can be utilized by both dairy and farming in future evaluation. If the data from the applied nutrients is coupled with the normal testing of both soil and tissue of the crops grown, a good picture of the efficiency of the nutrient management from this point on can be observed. The minimization of nutrient contamination is part of the good stewardship of our resources allowing long-term success of the modem dairy operations. It should be noted that the fertilizer components in the product water are efficiently incorporated into the irrigated plant materials and the quantity of this water used on a particular crop type should be monitored. In many cases the nutrients in this water is more than adequate for most crops. Because of this efficiency of utilization of the nutrients the possibility of contamination of the soil and ground water is minimized.
Summary January 2001:
Dissolved Oxygen and Airlift Mixing in the
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Terms used in the Report
- Bioremediation - the use of biological agents, such as bacteria or plants, to remove or neutralize contaiminants, as in polluted soil or water.
- Aeration - to supply with or to expose to, the circulation of air.
- Aerobic - living or occuring only in the presense of oxygen.
- Anaerobic - not requiring air or oxygen for life.
- Microbe - a microscopic organism; particularly applied to bactera and especially to pathogenic forms.
- BOD - Biologic Oxygen Demand. The amount of osygen required by aerogic microorganisms to decompose the organic matter in a sample of water.