title: Effects of tidal operation on pilot-scale horizontal subsurface flow constructed wetland treating sulfate rich wastewater contaminated by chlorinated hydrocarbons.
abstract: 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-1under continuous flow and 7-day cycle regime, respectively. However, sulfide concentrations decreased to less than 4 mg L-1under 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.
authors: College of Resources and Environment, Huazhong Agricultural University, Shizishan 1, Wuhan, 430070, China. zhongbing.chen@gmail.com.|Department of Applied Ecology, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, 16521, Prague, Czech Republic. zhongbing.chen@gmail.com.
authors: Zhongbing
authors: http://orcid.org/0000-0001-8801-4842
authors: Z
authors: Chen
authors: Department of Applied Ecology, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, 16521, Prague, Czech Republic.
authors: Jan
authors: J
authors: Vymazal
authors: Department of Environmental Biotechnology, Helmholtz Centre for Environmental Research-UFZ, Permoserstrasse 15, 04318, Leipzig, Germany.
authors: Peter
authors: P
authors: Kuschk
mesh_terms: D001673:Biodegradation, Environmental; D005858:Germany; D006843:Hydrocarbons, Chlorinated / Q000032:analysis*; D010865:Pilot Projects; D013431:Sulfates / Q000032:analysis*; D013440:Sulfides / Q000032:analysis; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods*; D053833:Wetlands
chemical_list: D006843:Hydrocarbons, Chlorinated; D013431:Sulfates; D013440:Sulfides; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Chlorobenzene; Constructed wetland; Groundwater; Perchloroethene; Tidal flow