| With the rapid development of large-scale livestock and poultry breeding,livestock and poultry breeding pollution has become one of the important tasks in the current rural environmental management in China.Mastering the migration and transformation of pollutants,especially nitrogen,in aquaculture wastewater is the basic work to effectively control aquaculture pollution..In this paper,through monitoring the nitrogen and phosphorus contents in the feed intake of pigs under different defecation methods and the contents of nitrogen and phosphorus in the excrement of different defecation methods,we can control the nitrogen and phosphorus intake of pigs from the feed with feces and urine.The amount of nitrogen and phosphorus discharged;monitoring the concentration of COD,total phosphorus,total nitrogen,ammonia nitrogen,nitrate nitrogen and nitrite in the treatment of pig breeding wastewater under different defecation methods,and mastering the process of treating pig breeding wastewater The migration and transformation of COD,phosphorus and nitrogen in wastewater;through the monitoring of ammonia emission concentration and meteorological conditions during the pig breeding process and manure treatment,calculate and analyze the ammonia emission flux,and master the ammonia in the process of pig manure treatment.Emissions rules.The conclusions reached are as follows:(1)Through the analysis and monitoring of the nitrogen and phosphorus in the feed intake of pigs and the amount of nitrogen and phosphorus in the excreta,it is shown that 50-70% of the nitrogen and 40-55% of the phosphorus in the feed are excreted into the environment through the excrement.(2)In the dry decontamination mode,when the collection rate of feces is 50-80%,the amount of nitrogen and phosphorus in the collected manure accounts for 37.08-53.12% and 42.29-46.37% of the total excretion of feces and urine,respectively;The amount of phosphorus accounted for 44.68-61.15% and 53.63-57.71% of the total excretion of feces and urine,respectively.Under the water flushing mode,when the collection rate of feces is 35-55%,the amount of nitrogen and phosphorus in the collected feces accounts for 23.18-33.08% and 23.49-32.52% of the total excretion of feces and urine,respectively.nitrogen and phosphorus in sewage The amount accounts for 60.71-73.83% and 67.48-76.51% of the total excretion of feces and urine,respectively.The content of nitrogen and phosphorus in feces and sewage under different defecation methods is mainly affected by factors such as the degree of manure removal,solid-liquid separation method and time.(3)About 22.85% of phosphorus,18.54% of carbohydrates,and 15.06% of nitrogen-containing substances in the feces of dry decontamination enter the wastewater,and the removal rate of phosphorus,COD and nitrogen in the sedimentation water is about 11.81%,7.99.%,10.50%.About 31.95% of phosphorus,21.91% of carbohydrates,and 8.54% of nitrogen-containing substances in the feces of the water-flushing method entered the wastewater.The removal rates of phosphorus,COD and nitrogen in the sedimentation water were about 19.75%,10.09%,6.00.%.Nitrogen content in wastewater under dry and clean manure is 70.04%,organic nitrogen accounts for 23.39%,nitrate nitrogen accounts for 0.40%,nitrite nitrogen accounts for 0.17%,and nitrogen content in wastewater under wastewater treatment is 67.22%.Nitrogen accounts for 32.19%,nitrate nitrogen accounts for 0.42%,and nitrite nitrogen accounts for 0.17%.(4)In the monitoring of the treatment process of the pig breeding wastewater at each stage,the pig waste water with a manure recovery rate of 60-80% in the drycleaning mode passes through the sedimentation tank-regulating tank-UASB-aerobic pool-storage pool After treatment,the total phosphorus,COD and total nitrogen concentrations in the water were removed to some extent.After treatment,the total total phosphorus,COD and total nitrogen removal in the wastewater were 31.85mg/L,5601.96mg/L and 426.34mg/L,respectively.The average removal amount of total phosphorus,COD and total nitrogen in the sedimentation tank accounted for 9.14%,5.90% and 9.24% of the total removal respectively;the total removal of total phosphorus,COD and total nitrogen in the adjustment tank accounted for 8.80 % of the total removal respectively.5.48%,7.34%;the average removal of total phosphorus,COD and total nitrogen in UASB accounted for 17.49%,75.41% and 14.38% of the total removal respectively;the average removal of total phosphorus,COD and total nitrogen in aerobic tank respectively The total removal amount was 63.14%,12.93%,and 68.84%;the total removal of total phosphorus,COD,and total nitrogen in the storage pool accounted for 1.44%,0.00%,and 0.00% of the total removal,respectively.(5)Through the monitoring of the various stages of the treatment of the pig breeding wastewater,the nitrogen in the wastewater is mainly present in the form of ammonia nitrogen and organic nitrogen and is removed from the water by a series of biochemical reactions under different treatment conditions.The nitrogen content of ammonia nitrogen,nitrate nitrogen,nitrite nitrogen and organic nitrogen in the sedimentation tank were 66.32-81.07%,0.24-0.35%,0.13-0.20% and 18.38-33.31%,respectively.The nitrogen content of ammonia nitrogen,nitrate nitrogen,nitrite nitrogen and organic nitrogen in the water in the regulation tank were 66.82-83.01%,0.25-0.37%,0.14-0.21% and 16.411-32.79%,respectively.The nitrogen content of ammonia nitrogen,nitrate nitrogen,nitrite nitrogen and organic nitrogen in the UASB accounted for 85.73-99.03%,0.30-0.40%,0.15-0.24% and 0.37-13.82%,respectively.The nitrogen content of ammonia nitrogen,nitrate nitrogen,nitrite nitrogen and organic nitrogen in the aerobic pool were 87.79-92.85%,0.19-0.51%,0.19-0.46% and 6.18-11.83%,respectively.The nitrogen content of ammonia nitrogen,nitrate nitrogen,nitrite nitrogen and organic nitrogen in the storage tank were 75.78-92.26%,0.19-0.51%,0.15-0.45%,and 6.78-61.86%,respectively.(6)When the weight of the pig is 20-70 kg and the house is cleaned once a day,when the total nitrogen concentration in the wastewater under the dry decontamination method is 201.54-274.35mg/L,the ammonia emission flux is 61.37-104.35mg/ min;when the total nitrogen concentration in the wastewater is 324.32-403.46mg/L,the ammonia emission flux is 43.58-87.25mg/min(7)Through the monitoring of ammonia emissions during the treatment of pig breeding wastewater,there is a positive correlation between the ammonia flux in the wastewater treatment process and the total nitrogen concentration in the wastewater through the sedimentation tank-regulation tank-aerobic tank-storage tank.The relationship between the ammonia discharge flux and the total nitrogen concentration in the wastewater in the sedimentation tank-regulation tank-aerobic tank-storage tank treatment process is: y=0.1567x-55.045,y=0.1094x-26.256,y= 0.6819x+13.131,y=0.5134x-21.073;the correlation is R2 sedimentation tank = 0.9902,R2 regulation tank = 0.9474,R2 aerobic tank = 0.9209,R2 storage pool = 0.9748. |
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