利用机械脱水技术对含水率较高的城市生活垃圾进行预处理,可显著降低垃圾渗滤液的产生或提高生活垃圾焚烧的效率。最近引起了极大的关注。然而,产生的有机物和含氮量高的机械脱水废水(MDW)已成为可持续处理MSW的重大挑战之一。在这项研究中,由物理化学预处理组成的中试规模集成系统,厌氧序批式反应器(ASBR),部分硝化SBR(PN-SBR),脱硝SBR(DN-SBR),和UV/O3高级氧化工艺,处理MDW的能力为1.0m3/d,其中化学需氧量(COD)/L有机物污染物超过34000mg/L,NH4-N为850mg/L,开发成功。通过对该集成系统的启动和工艺条件优化的探索,经过长期的系统运行,结果表明,该集成系统可以达到对COD的去除效率,NH4+-N和总氮(TN)的MDW为99.7%,98.2%和96.9%,分别。成功地获得了部分硝化和反硝化对TN的去除,亚硝酸盐积累率超过80%。处理条件参数优化为800mg/L聚氯化铝(PAC)和2mg/L聚丙烯酰胺(PAM),在pH为9的条件下进行预处理,ASBR的水力停留时间(HRT)为36h,PN-SBR为24小时,UV/O3单位为2小时。MDW中的有机源也被发现对于DN-SBR是可行的。因此,最终出水稳定符合排放标准,具有较高的稳定性和可靠性。
The municipal solid waste (MSW) with high water content can be pre-treated by the mechanical dewatering technology to significantly decrease the leachate generation in sequential landfill treatment or to improve the efficiency for solid waste incineration, which has attracted great concerns recently. However, the generated mechanical dewatering wastewater (MDW) containing high organics and nitrogenous content has been one of the big challenges for the sustainable treatment of MSW. In this study, a pilot-scale integrated system composed of physiochemical pretreatment, anaerobic sequencing batch reactor (ASBR), partial nitrification SBR (PN-SBR), denitrification SBR (DN-SBR), and UV/O3 advanced oxidation process, with a capacity of 1.0 m3/d to treat MDW containing over 34000 mg-chemical oxygen demand (COD)/L organics pollutant and 850 mg/L NH4+-N, was successfully developed. By explorations on the start-up of this integrated system and the process conditions optimization, after a long-term system operation, the findings demonstrated that this integrated system could reach the removal efficiency in the COD, NH4+-N and total nitrogen (TN) in the MDW of 99.7%, 98.2% and 96.9%, respectively. Partial nitrification and denitrification were successfully obtained for the TN removal with the nitrite accumulation rate of over 80%. The treatment condition parameters were optimized to be 800 mg/L polyaluminum chloride (PAC) and 2 mg/L polyacrylamide (PAM) under a pH of 9 for pretreatment, 36 h hydraulic retention time (HRT) for ASBR, 24 h for PN-SBR, and 2 h for UV/O3 unit. The organic sources in the MDW were also found to be feasible for the DN-SBR. Consequently, the resulting final effluent was stably in compliance with the discharge standard with high stability and reliability.