| In recent years, with the development of scale and industrialization for livestock farm, livestock farm developed to the areas such as suburbs or population intensive increasingly. Most large-scale livestock farm mostly built biogas project, which produced lots of biogas slurry, and most of them were taken direct emissions. However, biogas slurry still has a lot of organic pollutants, ammonia nitrogen, phosphorus, and also belongs to high-concentrate organic waste water. If taken direct emissions, it will cause great pressure on the environment and affect the survival and development of livestock farm. Taking a large-scale pig farms in Yunnan province as an example, through analyzing the characteristic of biogas slurry’s quality, this paper improved and optimized practical wastewater treatment technology of this pig farm in order to make treated water meet emissions or used as the water of piggery blunt column.For characteristics such as the high content of suspended solids or colloid, ammonia nitrogen, total phosphorus, difficult treatment and so on, farm anaerobic digestion colloidal suspensions content, high and concentrations, firstly this subject attempt to adopt group technology of Soft and Hard Packing Media Anaerobic Filter(SHAF)- aerobic process to deal with biogas slurry of this farm. The CODcr and suspended solids or colloid of biogas slurry are degraded and dislodged by SHAF, and aerobic ditch are used for subsequent processing which can remove ammonia nitrogen, total phosphorus in anaerobic digestive effluent.Firstly, the startup and running of SHAF were conducted. SHAF reactor was successfully startup through 54d~60d, which was relatively quickly relative to most of anaerobic reactor. After successful startup, CODcr removal rate of SHAF reactor was more than 70%. Water load of the reactor had a certain tolerance.After successful startup, SHAF went into efficiency research in which test SHAF reactor treated different CODcr concentration wastewater. The results showed that optimum influent CODcr concentrations for SHAF reactor are 1000±50mg/L~8000±100mg/L, namely organic volume loading is in 0.22~13.49kgCOD/m3?d1 range. CODcr concentrations of pig farm’s biogas slurry in this study is in 1000 mg/L~8000 mg/L range, so using SHAF reactor to deal with it is completely feasible. And through analysis, OLR has a great influence on efficiency of SHAF reactor. So when the influent water quality and operating conditions is under the same conditions, control of HRT is very important.On this basis, based on consideration of treatment effect of SHAF and economic, operation parameters of SHAF reactor when used to deal with pig farm’s biogas slurry were determined; and the best HRT was 40 h.Then, the startup and running of aerobic ditch were conducted. Using the method of cultivation and domestication two-step to start aerobic ditch, and the start time required was 40d~ 42 d, which was relatively quickly; after start-up of the reactor, removal rate of CODcr, NH3-N and TP can reach 60%. And on this basis, operation parameters of aerobic ditch were determined; and the best HRT was 24 h.Finally, treatment effect of SHAF- aerobic ditch was tested through the stable operation experiment, and the results showed that using the process to deal with a pig farm’s biogas slurry in Yunnan province is feasible;CODcr,SS, NH3-N and TP concentrations of effluent were 80-90 mg/L、0.21 mg/L、60~75 mg/Land 6.17mg/L, the removal rate of them were 94.44%、99.92%、71.16% and 70.02%, pH was in the normal range. Through the processed reached the livestock and poultry breeding wastewater discharge standard. |
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