Zhang Shi-Yang, Zhang Sheng-Hua, Zhang Xiang-Ling, Wang Guang-Jun
Key Laboratory of Tropical & Subtropical Fishery Resource Application and Cultivation, Ministry of Agriculture, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510380, China.
School of Civil Engineering and Architecture, Wuhan University of Technology, Wuhan 430070, China.
Huan Jing Ke Xue. 2017 Jun 8;38(6):2419-2428. doi: 10.13227/j.hjkx.201611024.
As an effective technology for wastewater treatment, bio-filter has been widely used. Nevertheless, there is still a lack of systematic report on purification efficiency and influencing factors of combined bio-filters. To this end, a novel combined system that consisted of aerated vertical-flow filter (AVF) followed by baffled horizontal-flow filter (BHF) was designed. After setting a series of hydraulic loading rates (131, 94 and 60 mm·d) and diversion ratios (8:2、6:4、4:6), we comprehensively assessed the impact of running condition adjustment on treatment performance by multiple statistical analyses. The results showed that, the average removal rates of organic matter, ammonia nitrogen and dissolved nitrogen in AVF were all above 80%, while the average removal rates of ammonia nitrogen, total nitrogen and dissolved nitrogen in BHF were all below 40%. Different running conditions had a significant (<0.05) impact on treatment performance. Meanwhile, there were significant differences in purification efficiency between the two different kinds of filters. Oxidative degradation was one of the main ways to remove organic matter in the two kinds of filters. There were obvious nitrification and denitrification processes within the two kinds of filters. Nitrification followed by denitrification was the main way to remove total nitrogen since ammonium occupied the most portion of total nitrogen in the synthetic wastewater. Meanwhile, the intensity of nitrification and denitrification in AVF was obviously higher than that in BHF. Phosphorus removal was mainly controlled by hydraulic loading rate, temperature, dissolved oxygen, organic matter, etc. This might indicate that microbial absorption was one of the main ways to remove phosphorus for the two filters. Compared to the sole AVF, the removal of total organic matter and total phosphorus in the combined system was increased by 4.4% and 23.2%, respectively, but the removal of total nitrogen was reduced by 12.1%. Reducing the diversion ratio was helpful to improve the denitrification intensity in BHF. However, due to the introduction of excessive ammonia from the raw wastewater, as well as the limited nitrification capacity in BHF, the removal rate of total nitrogen for the combined system was decreased. Therefore, according to the composition of treated raw wastewater, the control of appropriate diversion ratio, residence time and redox conditions inside the filter bed was the key to enhance the overall performance of the combined system.
作为一种有效的污水处理技术，生物滤池已被广泛应用。然而，关于组合生物滤池的净化效率和影响因素仍缺乏系统的报道。为此，设计了一种新型组合系统，该系统由曝气竖流滤池（AVF）和折流横流滤池（BHF）组成。在设定一系列水力负荷率（131、94和60mm·d）和分流比（8:2、6:4、4:6）后，通过多种统计分析方法综合评估了运行条件调整对处理性能的影响。结果表明，AVF中有机物、氨氮和溶解性氮的平均去除率均在80%以上，而BHF中氨氮、总氮和溶解性氮的平均去除率均在40%以下。不同的运行条件对处理性能有显著（<0.05）影响。同时，两种不同滤池的净化效率存在显著差异。氧化降解是两种滤池中去除有机物的主要方式之一。两种滤池内部均存在明显的硝化和反硝化过程。由于合成废水中铵占总氮的大部分，先硝化后反硝化是去除总氮的主要方式。同时，AVF中硝化和反硝化的强度明显高于BHF。除磷主要受水力负荷率、温度、溶解氧、有机物等控制。这可能表明微生物吸收是两种滤池除磷的主要方式之一。与单一AVF相比，组合系统中总有机物和总磷的去除率分别提高了4.4%和23.2%，但总氮的去除率降低了12.1%。降低分流比有助于提高BHF中的反硝化强度。然而，由于原废水中过量氨的引入，以及BHF中硝化能力有限，组合系统的总氮去除率降低。因此，根据待处理原废水的组成，控制滤床内合适的分流比、停留时间和氧化还原条件是提高组合系统整体性能的关键。
