Department of Civil Engineering, University of Asia Pacific, Dhaka, Bangladesh.
School of Engineering, Edith Cowan University, Joondalup, WA, 6027, Australia.
Environ Sci Pollut Res Int. 2019 Jan;26(1):586-599. doi: 10.1007/s11356-018-3637-z. Epub 2018 Nov 8.
An experimental study was carried out using in pilot-scale constructed wetland systems, operated in parallel to treat raw sewage. Each system consisted of a vertical flow (VF) unit that was filled with biochar as the main media, followed by a horizontal flow (HF) unit filled with crushed cement mortar. Hydraulic loading (HL) ranged 340-680 mm/day was applied on the VF wetland units, where high total nitrogen (TN) mass removal rate (20-23 g N/m d) was obtained, demonstrating that biochar media had a beneficial effect on the degradation of nitrogenous pollutants. Total phosphorus (TP) removal percentage (concentration based) was ≥ 86% in HF wetlands packed with mortar materials. In one system, the flow direction of the sewage was directed by the deployment of downflow pipes and vertical baffles, aiming to facilitate the formation of aerobic and anaerobic zones in the wetland matrices. The effects of such arrangement were analyzed by comparing pollutant removal efficiencies in the two systems. On average, 99, 96, 93, and 86 percentage removals were obtained for ammonia (NH-N), TN, biochemical oxygen demand (BOD), and TP, respectively, during the experiments. Biochar and crushed mortar proved to be a highly effective combination as media in subsurface flow constructed wetlands for wastewater treatment.
采用中试规模的人工湿地系统进行了一项实验研究，这些系统平行运行以处理原污水。每个系统都由一个垂直流（VF）单元组成，该单元以生物炭作为主要介质填充，然后是一个水平流（HF）单元，填充有碎水泥浆。VF 湿地单元的水力负荷（HL）范围为 340-680 mm/d，其中获得了高总氮（TN）去除率（20-23 g N/m d），表明生物炭介质对含氮污染物的降解有有益的影响。HF 湿地中用砂浆材料填充的总磷（TP）去除率（基于浓度）≥86%。在一个系统中，通过布置下降管和垂直挡板来改变污水的流向，旨在促进湿地基质中好氧和厌氧区的形成。通过比较两个系统的污染物去除效率来分析这种布置的效果。在实验过程中，氨（NH-N）、TN、生化需氧量（BOD）和 TP 的去除率平均分别为 99%、96%、93%和 86%。生物炭和碎砂浆被证明是作为污水地下流人工湿地的高效组合介质。
