The Effect On Pre-acidification In High Concentration Aniline Wastewater Treatment By Photosynthetic Bacteria

Currently,the main methods of treating aniline wastewater are physical and chemical methods,but the utilization of these tow kinds of methods to treat aniline wastewater has deficiencies as large covering area of facilities,expensive equipment, high operating costs and difficulty of controling the condition.Therefore,using biological treatment of aniline wastewater is the best choice.Most of the microorganism would die or dissolute due to the high concentration and toxicity of aniline wastewater and the effect of biological treatment was reduced while normal biological method was used to treat aniline wastewater. Thereby, to pursue the microorganism which could accommodate and degrade the aniline in the wastewater has become the technical difficulty to the biological treatment on aniline wastewater. This study used Photosynthetic Bacteria that can resiste high salt concentration and toxicity to treat aniline wastewater and researched the influence of pre-acidification process to PSB treatment on high concentration aniline wastewater.After determining the growth curve of Photosynthetic Bacteria and the optimal aeration time of PSB phase of Photosynthetic Bacteria treatment on aniline wastewater, this study investigated the influence of pre-acidification to PSB retention time and removal rate of CODCr and aniline in PSB and activated sludge phase,and the effect of microorganism in the wastewater was studied during each processing phase while using Photosynthetic Bacteria to treat the aniline wastewater.This type of aniline wastewater contained organic large molecular and substances that PSB couldn't treat directly.By pretreatment of acidogenesis bacteria, the average removal rate of CODcr could be improved.Compared with the wastewater without pre-acidification treatment, the HRT of pretreated wastewater could be reduced to 24h in PSB process,and it was 48h in wastwater without pretreatment.The pre-acidification treatment could reduce the concentration of aniline in high concentration chemical wastewater, improved the treating of aniline by PSB,reduced the inhibiting of microorganism in activated sludge by aniline,and provided a good substrate and environmental condition.Pre-acidification treatment--PSB--activated sludge process could treat this kind of aniline wastewater efficiently,the total CODcr removal rate could reach 90%,the content of aniline could be reduced to 0.71mg/L,the removal rate is 97.5%.Pretreatment of acidogenesis bacteria was good to the adsorption of PSB on biomembrane,it improved the treatment effect of wastewater in PSB process and activated sludge process.