印染废水NPEOs生物降解过程中内分泌干扰毒性生物强化削减研究
Study on bioaugmentation for endocrine disrupting toxicity control during NPEOs biodegradation in textile wastewater
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摘要: 印染废水中的壬基酚聚氧乙烯醚(NPEOs)在生物处理过程中会产生雌激素活性更强的壬基酚(NP)等中间产物,易引起处理后印染废水内分泌干扰毒性升高。为探究高效降解菌群对印染废水内分泌干扰毒性生物强化削减的效果,分别以NP10EO和NP为唯一碳源驯化富集印染活性污泥获得相应降解菌群NPEB和NPB,结果显示,生物量为5 mg/L的NPEB和NPB对10 mg/L NP10EO和NP的48 h降解率均高于98%;单独或组合投加5 mg/L NPEB和NPB至500 mg/L活性污泥体系均能显著提升活性污泥对不同浓度(10 mg/L和1 mg/L)NP10EO的降解性能,大幅缩短NP10EO降解过程雌激素活性变化周期,并使体系的雌激素活性维持在较低水平;相比之下,当体系中加入1000 mg/L葡萄糖作为额外碳源时,NPB的强化性能被完全抑制,而NPEB在降解性能受抑的情况下仍能增强活性污泥的NP10EO降解速率并缩短毒性控制时间。16S rRNA群落结构分析结果表明,NPEB和NPB中的优势菌属分别为Pseudomonas和Sphingobium,占比均超过50%,可能是参与NP10EO/NP降解和毒性控制的关键功能菌。Abstract: Nonylphenol ethoxylates (NPEOs) in textile wastewater can be biodegraded into more estrogenic potent intermediates such as NP during biological treatment, resulting in increased estrogenicity of secondary effluent when compared to the influent wastewater. In order to explore the bioaugmentation effect of bacterial consortium on controlling endocrine disrupting toxicity during textile wastewater treatment, NP10EO and NP were used as the sole carbon source to acclimate textile activated sludge to obtain the corresponding bacterial consortium NPEB and NPB, respectively. Experimental results showed that the 48 h degradation rates of 10 mg/L NP10EO and NP were higher than 98% when degraded with 5 mg/L NPEB and NPB, respectively. Single or combined addition of 5 mg/L NPEB and NPB to 500 mg/L activated sludge significantly improved its degradation performance towards NP10EO at different concentrations (10 mg/L and 1 mg/L), and markedly shortened the time for estrogenicity changing to complete during NP10EO degradation; also, the estrogenicity of the water matrix was maintained at relatively low levels. In contrast, when 1000 mg/L glucose was added into the biodegradation system as an additional carbon source, the bioaugmentation effect of NPB was completely inhibited, whereas NPEB could still improve of performance of activated sludge in degrading NP10EO as well as shorten the time needed for toxicity control even when its degradation ability was inhibited. Analysis of bacterial community structure through 16S rRNA gene showed that the dominant bacteria in NPEB and NPB were Pseudomonas and Sphingobium, accounting for more than 50% of the microbiome, which may be the key functional bacteria involved in NP10EO/NP degradation and toxicity control.
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Key words:
- Nonylphenol ethoxylates /
- textile wastewater /
- bioaugmentation /
- estrogenicity
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