title: Modeling and monitoring cyclic and linear volatile methylsiloxanes in a wastewater treatment plant using constant water level sequencing batch reactors.
abstract: The fate of cyclic and linear volatile methylsiloxanes (VMSs) was evaluated in a wastewater treatment plant (WWTP) using constant water level sequencing batch reactors from Dalian, China. Influent, effluent, and sewage sludge samples were collected for seven consecutive days. The mean concentrations of cyclic VMSs (cVMSs) in influent and effluent samples are 1.05 μg L(-1) and 0.343 μg L(-1); the total removal efficiency of VMSs is >60%. Linear VMS (lVMS) concentration is under the quantification limitation in aquatic samples but is found in sludge samples with a value of 90 μg kg(-1). High solid-water partition coefficients result in high VMS concentrations in sludge with the mean value of 5030 μg kg(-1). No significant differences of the daily mass flows are found when comparing the concentration during the weekend and during working days. The estimated mass load of total cVMSs is 194 mg d(-1)1000 inhabitants(-1) derived for the population. A mass balance model of the WWTP was developed and derived to simulate the fate of cVMSs. The removal by sorption on sludge increases, and the volatilization decreases with increasing hydrophobicity and decreasing volatility for cVMSs. Sensitivity analysis shows that the total suspended solid concentration in the effluent, mixed liquor suspended solid concentration, the sewage sludge flow rate, and the influent flow rate are the most influential parameters on the mass distribution of cVMSs in this WWTP.
authors: College of Environmental Science and Engineering, Dalian Maritime University, Dalian, PR China. Electronic address: degaowang@dlmu.edu.cn.
authors: De-Gao
authors: DG
authors: Wang
authors: College of Environmental Science and Engineering, Dalian Maritime University, Dalian, PR China.
authors: Juan
authors: J
authors: Du
authors: College of Environmental Science and Engineering, Dalian Maritime University, Dalian, PR China.
authors: Wei
authors: W
authors: Pei
authors: College of Environmental Science and Engineering, Dalian Maritime University, Dalian, PR China.
authors: Yongjun
authors: Y
authors: Liu
authors: College of Environmental Science and Engineering, Dalian Maritime University, Dalian, PR China.
authors: Mingxing
authors: M
authors: Guo
mesh_terms: D002681:China; D004784:Environmental Monitoring; D008956:Models, Chemical; D012833:Siloxanes / Q000032:analysis*; D014865:Waste Disposal, Fluid; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D012833:Siloxanes; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Constant water level sequencing batch reactor; Mass balance model; VMS; Wastewater treatment plant; Weekly use pattern