School of Civil Engineering, Guangzhou University, Guangzhou 510006, China.
Department of Architecture and Civil Engineering, City University of Hong Kong, Hong Kong Special Administrative Region; City University of Hong Kong, Shenzhen Research Institute, Shenzhen 518057, China.
Environ Pollut. 2018 May;236:137-145. doi: 10.1016/j.envpol.2018.01.042.
The occurrence, distribution and removal efficiencies of organophosphorus flame retardants (OPFRs) and metals were examined in a municipal landfill leachate treatment system in Guangzhou, China. Five OPFRs and thirty-five metals were detected in wastewater samples collected at different treatment stages. ∑OPFRs was reduced from 4807.02 ng L to 103.91 ng L through the treatment system, with close to 98% removed from the dissolved phase. Tris(clorisopropyl) phosphates (TCPPs) dominated through the treatment process and accounted for over 80% and 50% of ∑OPFRs at the influent and the effluent, respectively. TCPPs were most efficiently removed (98.6%) followed by tris(2-chloroethyl) phosphate (TCEP) (96.6%) and triphenyl phosphate (TPP) (88.5%). For metals, Fe, Cr, and Rb were dominant in the raw leachate, detected at 7.55, 2.82, and 4.50 mg L, respectively. Thirteen regulated heavy metals - including eight major pollutants (i.e., As. Cd, Cr, Cu, Hg, Ni, Pb, and Zn) - have been detected in all wastewater samples at sub-mg L levels. Over 99.5% removal was achieved for Cr, Ni, and Fe, and close to 95% removal efficiency was observed for Rb. For the eight major heavy metals, over 99% removal was observed; the only exception was Cu, which was removed at 89%. It was found that microfiltration/reverse osmosis was critical for the removal of OPFRs and heavy metals while the core biological treatment played a minor role towards their removal. Remobilization of Co, Cu, Fe, Hg, Mn, Ni, Sb, and Sr from the returned sludge occurred during the second denitrification, indicating the need for additional post-biological process for effective removal of both contaminants. This study highlights the critical need to develop cheap, effective treatment technologies for contaminants-laden leachate generated from open dumps and under-designed landfills.
在中国广州的一个城市垃圾填埋场渗滤液处理系统中，考察了有机磷阻燃剂（OPFRs）和金属的发生、分布和去除效率。在不同处理阶段采集的废水样品中检测到五种 OPFRs 和三十五种金属。∑OPFRs 通过处理系统从 4807.02ng/L 降低到 103.91ng/L，其中近 98%从溶解相中去除。三（氯异丙基）磷酸酯（TCPPs）在处理过程中占主导地位，在进水和出水处分别占∑OPFRs 的 80%和 50%以上。TCPPs 的去除效率最高（98.6%），其次是三（2-氯乙基）磷酸酯（TCEP）（96.6%）和磷酸三苯酯（TPP）（88.5%）。对于金属，Fe、Cr 和 Rb 在原始渗滤液中占主导地位，分别检测到 7.55、2.82 和 4.50mg/L。所有废水样品中均检测到 13 种受管制的重金属，包括八种主要污染物（即 As、Cd、Cr、Cu、Hg、Ni、Pb 和 Zn），含量均在亚毫克/升水平。Cr、Ni 和 Fe 的去除率超过 99.5%，Rb 的去除率接近 95%。对于八种主要重金属，去除率超过 99%；唯一的例外是 Cu，去除率为 89%。研究发现，微滤/反渗透对 OPFRs 和重金属的去除至关重要，而核心生物处理对其去除的作用较小。在第二次反硝化过程中，从回流污泥中重新释放出 Co、Cu、Fe、Hg、Mn、Ni、Sb 和 Sr，表明需要额外的生物后处理工艺来有效去除这两种污染物。本研究强调了开发廉价、有效的处理技术的迫切需要，以处理来自开放式垃圾场和设计不良的垃圾填埋场的富含污染物的渗滤液。
