HRT对3DBER-S工艺深度脱氮同步去除PAEs的影响

Effect of HRT on the Enhanced Nitrogen Removal in Synch With the Removal of PAEs by 3DBER-S Technology

为研究三维电极生物膜硫自养耦合脱氮(3DBER-S)工艺同步脱氮去除邻苯二甲酸酯(PAEs)的运行特性,分别针对3个水力停留时间(HRT)梯度(12 h→6 h→3 h),研究了耦合系统内总氮(TN)、PAEs去除及硫酸盐、p H变化情况,并分析了系统脱氮途径及PAEs去除能力.结果表明:在不同HRT下,TN去除率在95%左右,出水TN平均质量浓度均在2 mg/L以下;PAEs的平均去除率均超过80%,其中,邻苯二甲酸二丁酯(DBP)的平均去除率达97%以上,邻苯二甲酸二(2-乙基)己酯(DEHP)的平均去除率在83%以上.系统的最佳水力停留时间为6 h,该时段系统出水TN维持在0.80 mg·L-1左右,符合《地表水环境质量标准》中Ⅳ类水质标准的限值(1.5 mg/L);DBP、DEHP的平均去除负荷分别为594.79、188.13 mg/(m3·d).在3DBER-S系统内,单质硫和阴极产生的H2能够弥补由于HRT缩短、进水NO-3-N负荷增加所导致的反硝化电子供体相对不足问题,维持系统高效稳定的脱氮效率;同时,由于填料吸附、生物降解以及化学氧化等作用协同共存,对PAEs具有较强的去除能力.

In order to study the operation characteristics of 3DBER-S ( three-dimensional biofilm--electrode reactor coupled with sulfur autotrophic denitrification technology) in the aspect of denitrificationand simultaneous removal of PAEs (phthalate esters), the removal of TN (total nitrogen), PAEs,variation of sulfate and pH value as well as the denitrification route and the removal ability of PAEs in thecoupling system was traced and analyzed according to three different HRT (hydraulic retention time)which was 12 h, 6 h and 3 h respectively. The result show that under different HRT, the removalefficiency of TN is about 95%, the average effluent concentration of TN is under 2 mg/ L and the averageremoval rate of PAEs is above 80%. Also, the average removal rate of DBP (dibutyl phthalate) exceedes97%, while the number of DEHP (di-2-ethylhexyl phthalate) is more than 83%. The systems optimalhydraulic retention time is 6 h,the TN mass concentration of effluent maintaines around 0.80 mg/ L at this time interval, which meet the IV TN standard of Surface Water Environment Quality Standard (1.5 mg/L). The average removal loading of DBP and DEHP is 594.79 mg/ (m3·d) and 188.13 mg/ (m3·d)respectively. The elemental sulfur and the hydrogen produced by the cathode can remedy the relativeshortage of denitrification electronic donor resulted from HRT decreasing and NO-3 -N load increasing inthe influent, meanwhile can maintain the high efficiency and stability of the system, the strongelimination capacity of PAEs is due to the synergistic effect of filler absorption, biodegradation andelectrochemical oxidation.