Laboratory Simulation Study On The Anaerobic Biodegradability Of Natural Gas Purification Wastewater

Because the natural gas industry develops, the natural gas purification wastewater is becoming one of wastewater pollution sources, if this kind of wastewater is not been disposed, will be certain to impact the serious consequence on the natural environment. At present, the natural gas purification wastewater is mainly treated by aerobic biological process and physical chemical process. Because of intensely fluctuation of the quality and quantity of wastewater and containing cyclic nonbiodegradable organic compounds, the utility of these approaches are not very good, it is difficult to let it within emission control regulations .Especially physical chemical process, the operating costs are high, thus the applications of these methods in the treatment of such waste water is shrinking.Anaerobia can use nonbiodegradable organic compounds;during the process, some biochemical reaction which is impossible to occur in aerobic condition can occur, for example, the break of polycyclic aromatic hydrocarbons. So some nonbiodegradable organic compounds in aerobic condition is biodegradable in anaerobic condition. As concerning gas purification wastewater contains COD relatively high concentrations, and contains a lot of complex polycyclic aromatic hydrocarbons nonbiodegradable material characteristics, the thesis, in conjunction with the research results of predecessors, attempts to use anaerobic biological treatment + aerobic biological process to deal with such wastewater. To study the impact factors of natural gas purification wastewater degradability in the anaerobic, the author investigated a natural gas purification plant, and analyzed the quality of natural gas purification wastewater in site.Based on investigating findings and the anaerobic biological treatment theory, a static experiment was done in the laboratory, respectively researched on the impact to anaerobic wastewater biological degradability of the bacteria enrichment, PH, HRT, VSS concentration, influent COD concentration. Experimental results show that sludge enrichment can improve the biological degradability of such wastewater;At following state, PH about 8, VSS concentration in 4200mg/L, hydraulics time (HRT) for 72 hours, influent CODconcentration around 2500mg/L ,can get a better handling results.In conclusion, anaerobic degradability of natural gas purification wastewater is bad, but its biodegradability can be improved by bacteria enrichment and changing some condition and the thesis attained quite well good results.