The Federal University of Technology - Paraná (UTFPR), Civil Engineering Graduate Program, Deputado Heitor de Alencar Furtado St., 5000, Ecoville, 81280-340 Curitiba, Paraná, Brazil.
The Federal University of Technology - Paraná (UTFPR), Civil Construction Academic Department, Deputado Heitor de Alencar Furtado St., 5000, Ecoville, 81280-340 Curitiba, Paraná, Brazil.
Sci Total Environ. 2018 Jul 15;630:1365-1373. doi: 10.1016/j.scitotenv.2018.02.342. Epub 2018 Mar 7.
The present study aimed to assess removal potential of chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN), total ammonia nitrogen (TAN), total phosphorus (TP) and acetylsalicylic acid (ASA) in synthetic wastewater simulating low-strength sewage by sequencing-batch mode constructed wetlands (CWs). Six CWs with three substrates (gravel, light expanded clay and clay bricks) and one CW of each substrate was planted with E. crassipes to verify the feasibility of using a floating macrophyte in CWs and verify the best optimized substrate. Results showed that the presence of E. crassipes enhanced the removal of COD for systems with gravel, increasing the removal efficiency from 37% in the unplanted system (CW) to 60% in the planted system (CW). The vegetated CW with clay bricks (CW) presented the best performance for both TKN and TAN removal, with maximum removal efficiencies of 68% and 35%, respectively. Phosphorus was observed to be efficiently removed in systems with clay bricks, both planted (CW) and unplanted (CW), with mean removal efficiencies of 82% and 87%, respectively, probably via adsorption. It was also observed that after 296days of operation, no desorption or increase on phosphorus in effluent samples were observed, thus indicating that the material was not yet saturated and phosphorus probably presents a strong binding to the media. ASA removal efficiency varied from 34% to 92% in CWs, probably due to plant uptake through roots and microbial biodegradation. Plant direct uptake varied from 4 to 74% of the total nitrogen and from 26 to 71% of the total phosphorus removed in CW, CW and CW. E. crassipes was able to uptake up to 4.19g of phosphorus in CW and 11.84g of nitrogen in CW. The findings on this study suggest that E. crassipes could be used in CWs and clay bricks could significantly enhance phosphorus removal capacity in CWs.
本研究旨在评估序批式人工湿地（CWs）对模拟低强度污水的合成废水中化学需氧量（COD）、总凯氏氮（TKN）、总氨氮（TAN）、总磷（TP）和乙酰水杨酸（ASA）的去除潜力。六个 CW 采用三种基质（砾石、轻质膨胀粘土和粘土砖），每个基质一个 CW，并种植水蕹菜以验证 CW 中使用漂浮植物的可行性，并验证最佳优化基质。结果表明，水蕹菜的存在提高了砾石基质系统中 COD 的去除率，使无植物系统（CW）的去除效率从 37%提高到有植物系统（CW）的 60%。植物 CW 中粘土砖（CW）对 TKN 和 TAN 的去除效果最好，去除效率分别达到 68%和 35%。TP 被观察到在粘土砖基质系统中被有效去除，种植（CW）和未种植（CW）的系统去除率分别达到 82%和 87%，可能是通过吸附作用。还观察到，在运行 296 天后，没有观察到出水中磷的解吸或增加，因此表明材料尚未饱和，磷可能与介质有很强的结合力。ASA 的去除效率在 CW 中从 34%到 92%不等，可能是由于植物通过根系吸收和微生物生物降解。植物直接吸收占 CW 、CW 和 CW 总氮去除量的 4%至 74%，占总磷去除量的 26%至 71%。水蕹菜在 CW 中最多可吸收 4.19g 磷，在 CW 中最多可吸收 11.84g 氮。本研究的结果表明，水蕹菜可用于 CWs，粘土砖可显著提高 CWs 的磷去除能力。
