植物-SBR复合系统中碳氮磷去除途径与影响因素研究

发布时间：2018-08-22 16:57

【摘要】：景观生态活性污泥复合系统是将除污植物和传统活性污泥法(如序批式反应器,SBR)耦合的新型环境友好型污水处理系统。在植物和活性污泥的共同作用下,复合系统不仅具有稳定达标的出水水质,同时还兼具良好的景观性。但是,复合系统中除污单元对污染物去除贡献率仍不明确。本课题采用稳定同位素示踪技术研究复合系统中不同除污功能单元中碳氮磷的迁移转化与降解途径,考察不同温度与水中共存的纳米颗粒对各功能单元除污能力的影响,为深入理解复合系统的综合效能与指导其实际应用提供理论依据。利用稳定同位素示踪技术考察复合系统中碳氮磷的去除途径,并对各除污单元中污染物的去除贡献率综合分析。结果表明,进入复合系统的碳元素有54.6%以微生物代谢形式被去除,18.3%被活性污泥同化,约4%被除污植物去除。复合系统中的氮元素约48.6%通过被微生物通过硝化反硝化途径代谢后以氮气形式排入大气,约18.3%被活性污泥同化,约6.0%被植物综合作用去除,其中根系微生物的贡献作用最显著。进入复合系统的磷元素中,约62.0%存在于污泥中,8.2%被植物根部吸收,3.7%被植物茎部吸收,3.9%被植物叶部吸收。综合分析复合系统各除污单元的污染物去除贡献率表明,复合系统中活性污泥是去除污染物的主要途径,约占被去除污染物总量的70%,在除污植物种植密度为125株/m2条件下,耦合植物的综合作用对总碳、总氮和总磷的去除贡献率分别为4%、6%、14%。研究温度对复合系统污染物去除途径的影响行为,分析各除污单元的除污效能变化。结果表明,温度对各除污单元中总碳去除途径与贡献的影响不明显;当温度在15℃~30℃之间变化时,微生物硝化反硝化作用去除总氮的贡献率从46.5%增加至65.5%,活性污泥对总氮的同化作用贡献率从12.1%提高到24.1%,植物的综合作用贡献率从5%提高至8%。温度的升高对于总磷去除途径的影响也较大,会同时增加微生物同化、植物吸收与根系微生物同化等作用能力。考察了水体中共存的纳米颗粒对复合系统除污途径与各功能单元除污作用的影响,结果表明,当Ag NPs的浓度增至10 mg/L时,活性污泥对总碳、总氮的同化能力分别下降3%、0%,而根际微生物对总碳和总氮的去除贡献率分别下降1.4%、1.8%。共存的Zn O NPs浓度增加至100 mg/L才开始显著影响复合系统除污作用,导致活性污泥对总碳和总氮的同化作用降低3.3%和1.5%,根际微生物的对总碳和总磷的同化作用分别减低1.4%与2.5%,且出水中磷含量增加6%。
[Abstract]:Landscape ecological activated sludge complex system is a new environment-friendly sewage treatment system, which combines the decontamination plants with the traditional activated sludge process (such as sequencing batch reactor / SBR). Under the joint action of plant and activated sludge, the composite system not only has stable effluent quality, but also has good landscape. However, the contribution of decontamination units to pollutant removal in the composite system is still unclear. In this paper, the stable isotope tracer technique was used to study the migration, transformation and degradation of carbon, nitrogen and phosphorus in different decontamination function units in the composite system, and the effects of different temperature and water coexistence nanoparticles on the decontamination ability of each functional unit were investigated. It provides a theoretical basis for understanding the comprehensive efficiency of the composite system and guiding its practical application. The stable isotope tracer technique was used to investigate the removal of carbon, nitrogen and phosphorus in the composite system, and the contribution rate of pollutants removal in each decontamination unit was comprehensively analyzed. The results showed that 54.6% of the carbon elements entering the composite system were removed by microbial metabolism and 18.3% by activated sludge, and about 4% by decontamination plants. About 48.6% of the nitrogen elements in the composite system were metabolized by nitrification and denitrification, 18. 3% were assimilated by activated sludge, and 6. 0% were removed by the comprehensive action of plants. The contribution of root microbes was the most significant. About 62.0% of the phosphorus elements entering the complex system were absorbed by the roots of the plant and 3.7% by the stems, and 3.9% by the leaves of the plants. The comprehensive analysis of the pollutant removal contribution rate of each decontamination unit in the composite system shows that activated sludge is the main way to remove pollutants in the composite system, accounting for about 70% of the total amount of pollutants removed. Under the condition of 125 plants / m2 plant density, The total carbon, total nitrogen and total phosphorus removal contribution rate of the combined action of coupled plants was 4% and 6% respectively. The effect of temperature on the removal of pollutants in the composite system was studied, and the change of decontamination efficiency of each decontamination unit was analyzed. The results show that the effect of temperature on the total carbon removal pathway and contribution is not obvious, and when the temperature varies from 15 鈩，

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