Division of Biology, Faculty of Science and Technology, Rajamangala University of Technology Thanyaburi (RMUTT), Klong 6, Pathum Thani 12110, Thailand.
Excellent Center of Waste Utilization and Management (ECoWaste), King Mongkut's University of Technology Thonburi (KMUTT), Bangkhuntien, Bangkok 10150, Thailand.
Sci Total Environ. 2017 Aug 15;592:252-261. doi: 10.1016/j.scitotenv.2017.03.078. Epub 2017 Mar 17.
This research has assessed the removal efficiencies of toxic compounds in the high strength wastewater (the leachate and agriculture wastewater mixture) using the activated sludge (AS) and membrane bioreactor (MBR) technologies under two carbon to nitrogen (C/N) ratios (C/N 14 and 6) and two toxic compounds concentrations (8-396μg/L and 1000μg/L). In addition, the toxicity evaluations of the AS and MBR effluents to the aquatic environment were undertaken at five effluent dilution ratios (10, 20, 30, 50 and 70% v/v). The findings indicate that the AS treatment performance could be enhanced by the elevation of the nitrogen concentration. Specifically, the C/N 6 environment helps promote the bacterial growth, particularly heterotrophic nitrifying bacteria (HNB) and nitrifying bacteria (NB), which produce the enzymes crucial to the toxic compounds degradation. The improved biodegradation makes the effluents less toxic to the aquatic environment, as evidenced by the lower mortality rates of both experimental fish species raised in the nitrogen-elevated diluted AS effluents. On the other hand, the elevated nitrogen concentration minimally enhances the MBR treatment performance, given the fact that the MBR technology is in itself a biological treatment scheme with very high compounds removal capability. Despite its lower toxic compounds removal efficiency, the AS technology is simple, inexpensive and operationally-friendly, rendering the system more applicable to the treatment operation constrained by the financial, manpower and technological considerations.
本研究评估了在两种碳氮比（C/N 14 和 6）和两种有毒化合物浓度（8-396μg/L 和 1000μg/L）下，活性污泥（AS）和膜生物反应器（MBR）技术对高强度废水（渗滤液和农业废水混合物）中有毒化合物的去除效率。此外，还在五个出水稀释比（10%、20%、30%、50%和 70%v/v）下对 AS 和 MBR 出水对水生环境的毒性进行了评价。研究结果表明，提高氮浓度可以提高 AS 的处理性能。具体来说，C/N 6 环境有助于促进细菌生长，特别是异养硝化菌（HNB）和硝化菌（NB），它们产生的酶对有毒化合物的降解至关重要。由于在氮升高的稀释 AS 废水中饲养的实验鱼类的死亡率较低，因此提高了生物降解能力，使出水对水生环境的毒性降低。另一方面，由于 MBR 技术本身就是一种具有很高化合物去除能力的生物处理方案，因此提高氮浓度对 MBR 的处理性能的提升作用不大。尽管 AS 技术的有毒化合物去除效率较低，但它简单、廉价且易于操作，使系统更适用于受财务、人力和技术考虑因素限制的处理操作。
