Tondera Katharina, Klaer Kassandra, Koch Christoph, Hamza Ibrahim Ahmed, Pinnekamp Johannes
Institute of Environmental Engineering of RWTH Aachen University (ISA), 52056 Aachen, Germany.
Institute of Environmental Engineering of RWTH Aachen University (ISA), 52056 Aachen, Germany.
Int J Hyg Environ Health. 2016 Oct;219(7 Pt B):700-708. doi: 10.1016/j.ijheh.2016.04.009. Epub 2016 Apr 22.
Combined sewer overflows contribute significantly to pathogen loads in surface water. Some chemical disinfectants such as chlorine have proved to reduce the levels of microorganisms even in complex matrices such as wastewater in combined sewer systems; however, some of them release toxic by-products into water bodies and increase costs of plant maintenance and repair. In this study, we determined if performic acid (PFA) disinfection units can be operated at decentralized treatment facilities and reduce bacteria, viruses, and protozoan parasites in combined sewer overflows (CSOs). The PFA dosing unit at the inflow of a CSO storage tank dosed a fixed flow volume into the inflowing stormwater and, thus, concentrations varied between approximately 12-24mgl. The results showed a reduction of most hygienically relevant bacteria with mean removal efficiencies of 1.8log for Aeromonas spp. and 3.1log for E. coli. For viruses, however, reduction was only observed for somatic coliphages with 2.7log. In this setting, PFA does not seem to be suitable to remove e.g. protozoan parasites such as Giardia lamblia. In terms of operation, dosing the substance is uncritical in decentralized facilities, but the PFA needs too much time to react with pathogens after being dosed into the overflow of CSO storage tanks and before dilution with surface water in most facilities.
合流制下水道溢流是地表水中病原体负荷的重要来源。一些化学消毒剂，如氯，已被证明即使在合流制下水道系统中的废水等复杂基质中也能降低微生物水平；然而，其中一些消毒剂会向水体中释放有毒副产物，并增加工厂维护和维修成本。在本研究中，我们确定了过甲酸（PFA）消毒装置是否可以在分散式处理设施中运行，并减少合流制下水道溢流（CSO）中的细菌、病毒和原生动物寄生虫。CSO储水池入口处的PFA投加装置向流入的雨水中投加固定流量，因此浓度在约12 - 24mg/L之间变化。结果表明，大多数与卫生相关的细菌数量减少，嗜水气单胞菌的平均去除效率为1.8个对数，大肠杆菌为3.1个对数。然而，对于病毒，仅观察到体细胞噬菌体减少了2.7个对数。在这种情况下，PFA似乎不适用于去除例如蓝氏贾第鞭毛虫等原生动物寄生虫。在操作方面，在分散式设施中投加该物质并无关键问题，但在大多数设施中，PFA在投加到CSO储水池溢流中后，在与地表水稀释之前，需要太长时间才能与病原体发生反应。
