College of Resources and Environment, Huazhong Agricultural University, Shizishan 1, Wuhan, 430070, China.
Department of Applied Ecology, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, 16521, Prague, Czech Republic.
Environ Sci Pollut Res Int. 2017 Jan;24(1):1042-1050. doi: 10.1007/s11356-016-7871-y. Epub 2016 Oct 21.
Three different flow regimes were carried out in a pilot-scale horizontal subsurface flow constructed wetland-treating sulfate rich wastewater contaminated with monochlorobenzene (MCB) and perchloroethene (PCE). The three regimes were continuous flow, 7-day cycle discontinuous flow, and 2.5-day cycle discontinuous flow. The results show that intensifying the tidal regime (2.5-day cycle) significantly enhanced MCB removal before 2 m from the inlet and increasing PCE removal efficiency at 0.5 m. The PCE dechlorination process was promoted with tidal operation, especially under the 2.5-day cycle regime, with significant increases of cis-1,2- dichloroethenes (DCEs), vinyl chloride (VC), and ethene, but trans-1,2-DCE was significantly decreased after tidal operation. Due to the high sulfate concentration in the influent, sulfide was observed in pore water up to 20 and 23 mg L under continuous flow and 7-day cycle regime, respectively. However, sulfide concentrations decreased to less than 4 mg L under intensified tidal operation (2.5-day cycle). The increase of oxygen concentration in pore water through intensified tidal operation resulted in better MCB removal performance and the successful inhibition of sulfate reduction. In conclusion, intensifying tidal operation is an effective approach for the treatment of chlorinated hydrocarbons and inhibiting sulfide accumulation in horizontal subsurface flow constructed wetland.
三种不同的水流模式在一个中试规模的水平潜流人工湿地中进行，该湿地用于处理含有单氯苯（MCB）和全氯乙烯（PCE）的富硫酸盐废水。这三种模式分别是连续流、7 天周期不连续流和 2.5 天周期不连续流。结果表明，强化潮汐模式（2.5 天周期）在进水口前 2 米处显著提高了 MCB 的去除率，并提高了 0.5 米处的 PCE 去除效率。潮汐操作促进了 PCE 的脱氯过程，特别是在 2.5 天周期模式下，顺式-1,2-二氯乙烯（DCEs）、氯乙烯（VC）和乙烯的含量显著增加，但反式-1,2-DCE 在后潮汐操作后显著减少。由于进水硫酸盐浓度较高，在连续流和 7 天周期模式下，分别在 20 和 23mg/L 时观察到孔水中有硫化物。然而，在强化潮汐操作（2.5 天周期）下，硫化物浓度降低到 4mg/L 以下。通过强化潮汐操作增加孔水中的氧浓度，提高了 MCB 的去除性能，并成功抑制了硫酸盐还原。总之，强化潮汐操作是处理氯化烃和抑制水平潜流人工湿地中硫化物积累的有效方法。
