Santos Ana, Judd Simon
Centre for Water Science, Cranfield University, Bedford, Bedfordshire, UK MK43 0AL.
J Environ Monit. 2010 Jan;12(1):110-8. doi: 10.1039/b918161j. Epub 2009 Nov 24.
The fate of metals in wastewater treatment by the conventional activated sludge process (ASP) and membrane bioreactors (MBRs) is reviewed. The review outlines the environmental and health impacts of metals, but focuses primarily on data reported for removal of toxic metals, and some other high-profile inorganic micropollutants such as aluminium and arsenic, by wastewater treatment processes. Information from pilot and full scale plants is included, with corroboratory reports from bench-scale tests. General trends in removal across different metals are considered, along with the impact of the key process operating determinant of solids retention time. It is concluded that the only consistent trend in metals removal is that it is most effectively achieved through efficient solids separation, and that this represents the primary advantage offered by the MBR. As such, MBRs achieve averaged metals removals which are consistently but not dramatically higher than the ranges reported by the ASP: 64-92% vs. 51-87%, with no more than a 55% decrease on average in effluent concentration. The slightly greater removal attained is attributable to the additional suspended solids retention attained by the membrane process. In either case, further removal of metals would demand a tertiary process for removal of the dissolved material.
本文综述了传统活性污泥法（ASP）和膜生物反应器（MBR）处理废水中金属的去向。该综述概述了金属对环境和健康的影响，但主要关注废水处理过程中去除有毒金属以及一些其他备受关注的无机微污染物（如铝和砷）的相关数据。文中纳入了来自中试和全规模工厂的信息，以及来自实验室规模试验的确证报告。探讨了不同金属去除的总体趋势，以及固体停留时间这一关键工艺操作决定因素的影响。得出的结论是，金属去除方面唯一一致的趋势是通过高效的固液分离能最有效地实现去除，这也是MBR的主要优势所在。因此，MBR实现的金属去除平均率始终高于ASP报告的范围，但增幅并不显著：分别为64 - 92%和51 - 87%，出水浓度平均降幅不超过55%。实现的稍高去除率归因于膜工艺实现的额外悬浮固体保留。在任何一种情况下，进一步去除金属都需要采用三级工艺来去除溶解物质。
