| In recent years,with the increasing demand for meat products,livestock and poultry breeding industry has ushered in the rapid development of the opportunity,but followed by aquaculture wastewater pollution to the environment,Aquaculture wastewater not only has a large amount of water,but also has a high concentration of pollutants such as organic matter and ammonia nitrogen,the conventional biological treatments are difficult,effluent instability,It is still necessary to explore new treatment techniques to cope with the development trend of domestic aquaculture industry.In this study,the MAP-sacrificial iron anode activated PS oxidation technology was used for the combined pretreatment of high concentration of organic matter,ammonia nitrogen,total phosphorus and other pollutants in swine wastewater,aiming to reduce the effluent concentration of each pollutant and reduce the influent load for subsequent biological treatment.Combined process to explore the influence of COD,ammonia nitrogen,total phosphorus and other pollutants in swine wastewater removal effect,through the MAP precipitation recovery of swine wastewater ammonia nitrogen and phosphorus,reaction time,reaction p H value,Mg,N molar ratio and P,N molar ratio of ammonia nitrogen recovery effect;The COD and total phosphorus in swine wastewater were treated by activated PS oxidation technology with sacrificial iron anode.The effects of p H value,current density,reaction time and PS/COD on COD removal were investigated,and the optimal reaction conditions were selected.The main conclusions are as follows:（1）The MAP was used to recover ammonia nitrogen and total phosphorus from swine wastewater.The results showed that under the conditions of stirring reaction for 10 min,reaction p H value 9.5,Mg,N,P molar ratio 1:1:1,the removal rate of ammonia nitrogen and total phosphorus in swine wastewater was 90.7%and 89.1%,respectively.The effluent ammonia nitrogen and total phosphorus were lower than 50 mg/L and 10 mg/L,respectively.Through several ammonia nitrogen recovery experiments have verified that MAP has a stable ammonia nitrogen recovery effect on swine wastewater,and the ammonia nitrogen recovery rate is maintained between 86.8%and 93.9%.The environmental temperature has little influence on the recovery of ammonia nitrogen,and the precipitation drying temperature has a great influence on the purity of MAP.When the drying temperature is 40℃,the purity of MAP is the highest,and the purity of MAP in the obtained precipitate is 79.7%.（2）The supernatant of swine wastewater treated by MAP was treated by electrochemical oxidation.The results showed that under the conditions of p H 6,current density 5 m A/cm~2,PS/COD 1.5 and electrolytic reaction 40 min,the COD removal rate reaches 72.7%and the total phosphorus removal rate reaches 95%.After many experiments,the removal effect of COD is maintained between 64.1%and 74.4%,and that of TP is maintained between 92.9%and 99.7%.Adjust the p H of the electrolyte to neutral,precipitate the iron mud in the electrolytic system,the final effluent suspended matter concentration is 48 mg/L,suspended matter removal rate is 96.8%.（3）In this study,the combined pretreatment of swine wastewater by MAP-sacrifice iron anode activated PS oxidation technology greatly reduced the COD,ammonia nitrogen,total phosphorus and suspended solids in swine wastewater,and the pretreatment removal rates of each pollutant are 72.7%,90.7%,99.4%and 96.8%,respectively.The effluent concentrations are 870.3 mg/L,47.2 mg/L,0.5 mg/L and 48 mg/L,respectively.The economic value of MAP to recover ammonia nitrogen and phosphorus from swine wastewater is 18.77 yuan,and the energy consumption required by electrochemical oxidation technology is 6.68 yuan/kg COD. |
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