水洗碳氢溶剂废气的废水生物降解效能及影响因素研究

Study on biodegradation efficiency and influencing factors of wastewater of washing exhaust from hydrocarbon solvent

采用厌氧折流板反应器(ABR)/连续搅拌反应器(CSTR)组合工艺,通过构建共基质体系对水洗碳氢溶剂废气的废水(简称水洗废水)进行处理研究,探讨了共基质体系可行性,考察了水力停留时间(HRT)、硝化液回流比(R,%)、COD和氨氮质量比(C/N)、pH等对水洗废水处理效率的影响。结果表明:(1)共基质体系对去除水洗废水中难降解有机物效果显著。水洗废水占总废水的体积分数≤60%时共代谢效果最佳,COD平均去除率高于84%,氮污染物的去除受该体系影响小。(2)HRT=12 h时碳污染物去除效果最佳,COD平均去除率为89.40%。较长的HRT利于脱氮,HRT=24 h时氨氮平均去除率达98%,平均出水氨氮为0.87 mg/L。R=300%(体积分数)时碳氮污染物去除效果最优。(3)C/N=10时组合装置对废水的脱氮除碳性能最好,COD、总有机碳(TOC)、氨氮和TN平均去除率分别为87.93%、93.11%、95.94%和77.29%。除碳最适pH为6.7,脱氮偏好碱性环境(pH=8.6)。

The anaerobic baffled reactor-continuous stirred tank reactor(ABR/CSTR)combined process was used to treat the wastewater of washing exhaust from hydrocarbon solvent(referred to as washing wastewater)by building the co-substrate system.Feasibility of co-substrate system was discussed.And the effects of hydraulic retention time(HRT),nitrated liquid reflux ratio(R,%),mass ratio of COD and ammonia nitrogen(C/N)and pH on the treatment effects of washing wastewater were investigated.The results showed:(1)the removal effect of refractory organics in washing wastewater was significant by co-substrate system.And the effect of co-metabolism was the best when the volume fraction of washing wastewater in total wastewater≤60%,the average removal rate of COD was more than 84%.The removal of nitrogen contaminants was less affected by the system.(2)When HRT=12 h,the removal effect of the carbon contaminants was best,average removal rate of COD was 89.40%.Longer HRT was better for nitrogen removal,the average removal rate of ammonia nitrogen was 98%and average effluent ammonia nitrogen was 0.87 mg/L when HRT=24 h.The contaminants removal effects of carbon and nitrogen were optimal when R=300%.(3)The combined reactor had the best denitrification and carbon removal performance for wastewater when C/N=10,the average removal rate of COD,TOC,ammonia nitrogen and TN were 87.93%,93.11%,95.94%and 77.29%,respectively.The best pH for carbon removal was 6.7,denitrification preferred alkaline environment(pH=8.6).