Kitchen waste anaerobic digestion wastewater treating method

Abstract

The invention provides a kitchen waste anaerobic digestion wastewater treating method which is used for treating wastewater produced from kitchen waste slurry after anaerobic digestion and dewatering and wastewater produced in other procedures of kitchen waste treatment. The wastewater is subjected to oil-separation primary sedimentation, water quantity and water quality regulation, first pH regulation, free ammonia stripping in an ammonia stripping tower, second pH regulation, A / O biochemical treatment, sedimentation treatment, air floatation treatment, treatment in a Fenton reactor, treatment in a coagulative sedimentation tank and treatment in a biological aerated filter in sequence. With adoption of the method, pollutants such as COD (chemical oxygen demand), BOD5 (biochemical oxygen demand), SS (suspended solids) and the like in the wastewater are removed effectively, TN (total nitrogen) and TP (total phosphorus) can be removed effectively, wastewater chroma can be reduced effectively, TN and TP removal rate is increased, the pollutants such as COD, BOD5, NH3-N, TP and the like in the treated wastewater as well as the chroma of the treated wastewater can stably meet requirements of level-1 in the integrated wastewater discharge standard (GB8978-1996), and TN is smaller than 70 mg / L.

Description

technical field [0001] The invention relates to a method for treating kitchen waste wastewater, in particular to a method for treating waste water after anaerobic digestion and dehydration of kitchen waste slurry and waste water produced in other processes of kitchen waste treatment, and belongs to the field of sewage treatment. Background technique [0002] Wastewater after anaerobic digestion and dehydration of food waste slurry, as well as waste water generated by other processes of food waste treatment, has complex components and is a high-concentration organic wastewater that is difficult to treat. The concentration of pollutants in wastewater is high, chemical oxygen demand (COD, 8000-20000mg / L), biochemical oxygen demand (BOD 5 , 4000~8000mg / L), total nitrogen (TN, 2000~3000mg / L), ammonia nitrogen (NH 3 -N, 1500~2500mg / L), total phosphorus (TP, 50~150mg / L), suspended solids (SS, >8000mg / L), salt content (15000~30000mg / L), animal and vegetable oil (800~1500mg / L),...

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Problems solved by technology

[0004] Publication No. CN106746174A discloses "A Method for Treating Kitchen Waste Slurry Anaerobic Fermentation Wastewater", which is used for the treatment of waste water after anaerobic fermentation and dehydration of kitchen waste slurry and waste water generated in other processes of kitchen waste treatment. The steps are in sequence: oil separation primary sedimentation, water quantity and water quality adjustment, first pH adjustment, ammonia stripping tower free ammonia stripping, second pH adjustment, A / O biochemical treatment, precipitation treatment, Fenton reactor treatment , coagulation sedimentation tank treatment, COD, BOD in the wastewater treated by this method 5 , TN, NH 3 - N, TP, chroma and other pollutants can stably meet the "Comprehensive Discharge Standard for Sewage" (GB8978-1996) "Class III Standard" and "Water Quality Standard for Sewage Discharge into Urban Sewers" GB / T 31962-2015) "Class B "Requirements, has a good effect, but does not meet the "Integrated Wastewater Discharge Standard" (GB8978-1996) "first-level standard" requirements

[0005] In the prior art, there is also a method called "kitchen waste wastewater treatment method". The steps include: first pretreatment to remove solid impurities, oil, sticky matter, etc. in the wastewater, and then pass through the anaerobic biofilm reactor respectively. , The aerobic biofilm reactor acidifies and removes the organic matter in the wastewater, and finally discharges it after being treated by the reverse osmosis membrane; The disadvantages are, first, the operation and management requirements of the anaerobic treatment unit in this method are high, especially the carbon source in the wastewater is consumed by the anaerobic treatment unit during operation, so that the carbon-nitrogen ratio in the wastewater is further reduced (COD, BOD 5 reduction, ammonia nitrogen increase), the reduction of carbon-to-nitrogen ratio is not conducive to the biological denitrification of wastewater; the second is that the reverse osmosis membrane treatment technology adopted in this method can meet the "B level" of the "Water Quality Standards for Sewage Discharge into Urban Sewers" The requirements of the standard and the requirements of the "Class I Standard" of the "Integrated Wastewater Discharge Standard" (GB8978-1996), its shortcomings are: the oil in the wastewater can easily cause membrane blockage, and the high salt in the wastewater will accelerate the aging of the membrane. The lifespan is short, especially membrane technology is a physical filtration technology, which only intercepts the pollutants in the wastewater, but does not really degrade the pollutants. Secondary pollution and higher operating costs

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