Department of Environmental Engineering, Faculty of Engineering, Rajamangala University of Technology Thanyaburi (RMUTT), Klong 6, Pathum Thani 12110, Thailand.
Faculty of Geosciences and Civil Engineering, Institute of Science and Engineering, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.
Sci Total Environ. 2020 Jul 1;724:138275. doi: 10.1016/j.scitotenv.2020.138275. Epub 2020 Mar 27.
This research comparatively investigates the effect of landfill leachate effluent of two biological treatment schemes on germination of Lactuca sativa and Vigna radiata. The treatment schemes are two-stage activated sludge (AS) and two-stage membrane bioreactor (MBR) systems with acclimatized seed sludge. The AS and MBR are operated under two concentrations of landfill leachate influent: moderate (condition 1) and elevated (condition 2). The results show that, under condition 1, the AS and MBR efficiently remove 80-96% of organic compounds and nutrients and 81-100% of harmful micropollutants. Under condition 2 with elevated influent concentration, MBR is more effective in biodegrading micropollutants than the AS system. The germination rate (GR) and germination seed index (GSI) of L. sativa and V. radiata germinated with AS and MBR effluent from condition 1 are 100% and 1.29-1.56. Under condition 2, the GR and GSI with AS effluent are reduced to 80% and 0.65-0.77, while those with MBR effluent are 100% and 1.27-1.38. Quantitative real-time polymerase chain reaction (qPCR) analysis indicates that the bacterial community in the MBR is more abundant than in the AS, especially ammonia oxidizing bacteria, Nitrobacter, and Nitrospira, which aid heterotrophic bacteria in biodegradation of micropollutants and promote the growth of heterotrophs. The bacterial abundance and community composition render the MBR scheme more operationally suitable for elevated landfill-leachate influent concentrations. By comparison, the MBR system is more effective in removal of micropollutants than the AS, as evidenced by higher GR and GSI. The technology also could potentially be applied to water reclamation. A lack of technological and financial resources in many developing countries nevertheless precludes the adoption of MBR despite higher pollutant removal efficiency. An alternative solution is the use of acclimatized seed sludge in AS system to enhance treatment efficiency, especially in influent with low concentrations of micropollutants. In addition, the seed germination results suggest the possibility of water reuse in agriculture.
本研究比较了两种生物处理方案（两段式活性污泥法（AS）和两段式膜生物反应器法（MBR））的垃圾渗滤液对莴苣（Lactuca sativa）和豇豆（Vigna radiata）种子萌发的影响。该处理方案采用驯化后的种泥。AS 和 MBR 均在两种垃圾渗滤液浓度条件下运行：中浓度（条件 1）和高浓度（条件 2）。结果表明，在条件 1 下，AS 和 MBR 可高效去除 80-96%的有机化合物和营养物质以及 81-100%的有害微量污染物。在高浓度渗滤液条件 2 下，MBR 比 AS 系统更有效地生物降解微量污染物。用 AS 和 MBR 条件 1 下的出水培养的莴苣和豇豆种子的发芽率（GR）和发芽种子指数（GSI）均为 100%和 1.29-1.56。在条件 2 下，AS 出水的 GR 和 GSI 降低至 80%和 0.65-0.77，而 MBR 出水的 GR 和 GSI 为 100%和 1.27-1.38。实时荧光定量聚合酶链反应（qPCR）分析表明，MBR 中的细菌群落比 AS 中的更为丰富，特别是氨氧化菌、硝化菌和反硝化菌，它们有助于异养菌对微量污染物的生物降解，并促进异养菌的生长。细菌丰度和群落组成使 MBR 方案更适合高浓度的垃圾渗滤液。相比之下，MBR 系统对微量污染物的去除效果更好，表现为更高的 GR 和 GSI。该技术也有可能应用于水的再利用。然而，许多发展中国家缺乏技术和财政资源，尽管 MBR 具有更高的污染物去除效率，但仍无法采用该技术。一种替代解决方案是在 AS 系统中使用驯化后的种泥来提高处理效率，特别是在微量污染物浓度较低的进水条件下。此外，种子发芽结果表明了农业中废水再利用的可能性。
