title: Mechanism and Parameter Optimization of Fenton's Reagent Integrated with Surfactant Pretreatment to Improve Sludge Dewaterability.
abstract: Sludge dewatering can effectively reduce the volume and mass of sludge for subsequent treatment and disposal. The work validated the potential of Fenton's reagent combined with dodecyl dimethyl benzyl ammonium chloride (DDBAC) in improving sludge dewaterability and proposed the mechanism of joint conditioning. The composite conditioner dosage was optimized using response surface methodology. Results indicated the good conditioning capability of the composite conditioners. The optimum dosages for H2O2, Fe2+, and DDBAC were 44.6, 39.6, and 71.0 mg/g, respectively, at which a sludge cake water content of 59.67% could be achieved. Moreover, a second-order polynomial equation was developed to describe the behavior of joint conditioning. Analysis of the reaction mechanism showed that Fenton oxidation effectively decomposed extracellular polymeric substance (EPS), including loosely bound EPS (LB-EPS) and tightly bound EPS (TB-EPS), into dissolved organics, such as proteins and polysaccharides. The process facilitated the conversion of the bound water into free water. Furthermore, DDBAC further released the bound water through solubilization of TB-EPS and LB-EPS after the Fenton reaction. The bound water content of the sludge conditioned with Fenton's reagent decreased from 3.15 to 1.36 g/g and further decreased to 1.08 g/g with the addition of DDBAC. High-performance liquid chromatography analysis verified that the composite conditioning could oxidize and hydrolyze EPS into low-molecular-mass organics (e.g., formic and acetic acid), thereby facilitating the release of bound water.
authors.affiliation: Department of Environmental Engineering, University of Science and Technology Beijing, Beijing, China.|Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Xing
authors.affiliation: Department of Environmental Engineering, University of Science and Technology Beijing, Beijing, China.|Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing, China.
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Department of Environmental Engineering, University of Science and Technology Beijing, Beijing, China.|Reasearch Center for Eco-Environmental Sciences, Chinese Academy of Science, Beijing, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Hong
authors.affiliation: Department of Environmental Engineering, University of Science and Technology Beijing, Beijing, China.|Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Yang
authors.affiliation: Department of Environmental Engineering, University of Science and Technology Beijing, Beijing, China.|Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing, China.
authors.forename: Lihui
authors.initials: L
authors.lastname: Feng
authors.affiliation: Department of Environmental Engineering, University of Science and Technology Beijing, Beijing, China.|Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing, China.
authors.forename: Mengmeng
authors.initials: M
authors.lastname: Jia
authors.affiliation: Department of Environmental Engineering, University of Science and Technology Beijing, Beijing, China.|Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing, China.
authors.forename: Yifei
authors.initials: Y
authors.lastname: Li
mesh_terms: D001548:Benzalkonium Compounds / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D012722:Sewage / Q000737:chemistry*; D013501:Surface-Active Agents / Q000737:chemistry*; D018508:Water Purification
chemical_list: D001548:Benzalkonium Compounds; C045076:Fenton's reagent; D012722:Sewage; D013501:Surface-Active Agents; D006861:Hydrogen Peroxide; D007501:Iron