title: Dissolved organic matter removal during coal slag additive soil aquifer treatment for secondary effluent recharging: Contribution of aerobic biodegradation.
abstract: Recycling wastewater treatment plant (WWTP) effluent at low cost via the soil aquifer treatment (SAT), which has been considered as a renewable approach in regenerating potable and non-potable water, is welcome in arid and semi-arid regions throughout the world. In this study, the effect of a coal slag additive on the bulk removal of the dissolved organic matter (DOM) in WWTP effluent during SAT operation was explored via the matrix configurations of both coal slag layer and natural soil layer. Azide inhibition and XAD-resins fractionation experiments indicated that the appropriate configuration designing of an upper soil layer (25 cm) and a mixture of soil/coal slag underneath would enhance the removal efficiency of adsorption and anaerobic biodegradation to the same level as that of aerobic biodegradation (31.7% vs 32.2%), while it was only 29.4% compared with the aerobic biodegradation during traditional 50 cm soil column operation. The added coal slag would preferentially adsorb the hydrophobic DOM, and those adsorbed organics could be partially biodegraded by the biomass within the SAT systems. Compared with the relatively lower dissolved organic carbon (DOC), ultraviolet light adsorption at 254 nm (UV-254) and trihalomethane formation potential (THMFP) removal rate of the original soil column (42.0%, 32.9%, and 28.0%, respectively), SSL2 and SSL4 columns would enhance the bulk removal efficiency to more than 60%. Moreover, a coal slag additive in the SAT columns could decline the aromatic components (fulvic-like organics and tryptophan-like proteins) significantly.
authors.affiliation: School of Municipal & Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China; Department of Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA.
authors.forename: Liangliang
authors.initials: L
authors.lastname: Wei
authors.affiliation: School of Municipal & Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China. Electronic address: weill333@163.com.
authors.forename: Siliang
authors.initials: S
authors.lastname: Li
authors.affiliation: Department of Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA.
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Noguera
authors.affiliation: School of Municipal & Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China.
authors.forename: Kena
authors.initials: K
authors.lastname: Qin
authors.affiliation: School of Municipal & Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China.
authors.forename: Junqiu
authors.initials: J
authors.lastname: Jiang
authors.affiliation: School of Municipal & Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China; State Key Laboratory of Urban Water Resources and Environment (SKLUWRE), Harbin Institute of Technology, Harbin 150090, China. Electronic address: zhql1962@163.com.
authors.forename: Qingliang
authors.initials: Q
authors.lastname: Zhao
authors.affiliation: Center of Science & Technology of Construction of the Ministry of Housing and Urban Rural Development, China.
authors.forename: Xiangjuan
authors.initials: X
authors.lastname: Kong
authors.affiliation: School of Municipal & Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China; State Key Laboratory of Urban Water Resources and Environment (SKLUWRE), Harbin Institute of Technology, Harbin 150090, China.
authors.forename: Fuyi
authors.initials: F
authors.lastname: Cui
mesh_terms: D000327:Adsorption; D001673:Biodegradation, Environmental; D003031:Coal; D060587:Groundwater / Q000737:chemistry*; D009930:Organic Chemicals; D059027:Recycling; D012037:Refuse Disposal / Q000379:methods; D012987:Soil / Q000737:chemistry*; D022882:Trihalomethanes; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
chemical_list: D003031:Coal; D009930:Organic Chemicals; D012987:Soil; D022882:Trihalomethanes; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Azide-inhibition; Coal slag; Dissolved organic matter (DOM); Fractionation; Soil aquifer treatment (SAT)