title: Potential contribution of inorganic ions to whole effluent acute toxicity and genotoxicity during sewage tertiary treatment.
abstract: Two acute toxicity tests (luminescent bacteria assay and cladoceran assay) and one genotoxicity test (broad bean assay) were used to evaluate whole effluent toxicity during the standard anion exchange resin-based pilot-scale sewage tertiary treatment that stably achieved significant dissolved organic carbon and inorganic ions reduction. The effect of six representative inorganic ions (i.e., Cl(-), SO4(2-), NO3(-)-N, NO2(-)-N, NH4(+)-N and PO4(3-)-P) on the acute toxicity and genotoxicity was further investigated. Significant whole effluent genotoxicity reduction was observed as an ∼ 57% micronucleated cell frequency reduction and ∼ 46% mitotic index increment during the pilot-scale periods, which should be attributed to significant organic removal since no significant (p ≥ 0.116) increase in genotoxicity was observed with the increase in these ionic concentrations. However, no significant (p ≥ 0.14) reductions were observed for whole effluent acute toxicity using two acute toxicity assays during the pilot-scale periods, and these inorganic ions, especially NH4(+)-N, contributed considerably to the acute toxicity. Based on Pearson correlation coefficients, whole effluent acute toxicity showed significant positive (p < 0.001, r ≥ 0.758) correlations with the NH4(+)-N concentration. Two optimal models were finally developed using step-wise multiple linear regression to predict the whole effluent acute toxicity via NH4(+)-N concentrations.
authors.affiliation: School of Environment, MOE Key Laboratory of Water and Sediment Sciences/State Key Lab of Water Environment Simulation, Beijing Normal University, Beijing 100875, PR China.
authors.forename: Jian
authors.initials: J
authors.lastname: Sun
authors.affiliation: School of Environment, MOE Key Laboratory of Water and Sediment Sciences/State Key Lab of Water Environment Simulation, Beijing Normal University, Beijing 100875, PR China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Quan
authors.affiliation: School of Environment, MOE Key Laboratory of Water and Sediment Sciences/State Key Lab of Water Environment Simulation, Beijing Normal University, Beijing 100875, PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.affiliation: School of Environment, MOE Key Laboratory of Water and Sediment Sciences/State Key Lab of Water Environment Simulation, Beijing Normal University, Beijing 100875, PR China. Electronic address: zsk@bnu.edu.cn.
authors.forename: Shaokui
authors.initials: S
authors.lastname: Zheng
authors.affiliation: College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, PR China. Electronic address: xcliu@ucas.ac.cn.
authors.forename: Xinchun
authors.initials: X
authors.lastname: Liu
mesh_terms: D000818:Animals; D003621:Daphnia; D007477:Ions / Q000633:toxicity*; D009152:Mutagenicity Tests; D012722:Sewage; D018505:Waste Management; D062065:Wastewater / Q000633:toxicity*
chemical_list: D007477:Ions; D012722:Sewage; D062065:Wastewater
keywords: Acute toxicity; Genotoxicity; Inorganic ion; Sewage; Tertiary treatment