The University of Queensland, Advanced Water Management Centre (AWMC), Brisbane, Qld 4072, Australia.
The University of Queensland, Advanced Water Management Centre (AWMC), Brisbane, Qld 4072, Australia.
Water Res. 2014 May 1;54:89-99. doi: 10.1016/j.watres.2014.01.030. Epub 2014 Feb 6.
The objective of this study was to determine the extent to which a suite of organic micropollutants (MPs) can be removed by biological filtration and the role of bioavailability and ammonia oxidizing microorganisms (AOMs) in the biodegradation process. During approximately one year, laboratory-scale columns with 8 min empty bed contact time (EBCT) and packed with anthracite as filter media were used for treating a tertiary effluent spiked with a broad range of MPs at a target concentration of 2 μg L(-1). In parallel columns, aerobic biomass growth was inhibited by using either the biocide sodium azide (500 mg L(-1) NaN3) or allylthiourea (5 mg L(-1) ATU), specifically inhibiting nitrifying bacteria. Once the biomass had colonized the media, around 15% of the dissolved organic carbon (DOC) contained in the untreated tertiary effluent was removed by non-inhibited columns. The removal of several MPs increased over time indicating the relevance of biological activity for the removal of MPs, while the negative control, the NaN3 inhibited column, showed no significant removal. Out of 33 MPs, 19 were recalcitrant (<25%) to biodegradation under aerobic conditions with the others exhibiting a diverse range of removal efficiency up to 95%. Through inhibition by ATU it was shown that nitrifying bacteria were clearly having a role in the degradation of several MPs, whereas the removal of other MPs was not affected by the presence of the nitrification inhibitor. A relationship between the qualitative assessment of sorption of MPs on granular activated carbon (GAC) and their removal efficiency by biodegradation on anthracite was observed. This result suggested that the affinity of the MPs for GAC media could be a useful indicator of the bioavailability of compounds during biofiltration on anthracite.
本研究旨在确定一系列有机微污染物（MPs）在多大程度上可以通过生物过滤去除，以及生物可利用性和氨氧化微生物（AOMs）在生物降解过程中的作用。在大约一年的时间里，使用 8 分钟空床接触时间（EBCT）并填充无烟煤作为过滤介质的实验室规模柱用于处理经过广泛范围 MPs 污染的三级出水，目标浓度为 2μg/L(-1)。在平行柱中，通过使用杀菌剂叠氮化钠（500mg/L(-1)NaN3）或烯丙基硫脲（5mg/L(-1)ATU）抑制好氧生物量生长，专门抑制硝化细菌。一旦生物量殖民了介质，未受抑制的柱子就会去除未经处理的三级出水中约 15%的溶解有机碳（DOC）。随着时间的推移，几种 MPs 的去除率增加，表明生物活性对于 MPs 的去除很重要，而作为阴性对照的 NaN3 抑制柱则没有显示出明显的去除效果。在 33 种 MPs 中，有 19 种在好氧条件下不易生物降解（<25%），其余的去除效率则从 25%到 95%不等。通过 ATU 抑制实验表明，硝化细菌显然在几种 MPs 的降解中发挥了作用，而其他 MPs 的去除则不受硝化抑制剂的影响。观察到 MPs 在颗粒活性炭（GAC）上的吸附定性评估与在无烟煤上的生物降解去除效率之间存在关系。这一结果表明，MPs 对 GAC 介质的亲和力可能是生物过滤过程中化合物生物可利用性的有用指标。
