MIEX Resin Adsorption-electrolysis Two-step Method To Remove Brominated Flame Retardants In Water

Recently,the product and waste treatment of brominated flame retardants with mutagenesis,carcinogenesis,teratogenesis have caused more and more serious water pollution problems,which great threaten the human's health and life.Therefore,it is very important to develop the efficient,environment friendly treatment technology.In this paper,tetrabromobisphenol A(TBBPA)and 2,4,6-Tribromophenol(TBP),two kinds of typical brominated flame retardants were selected as target pollutants,which researched by magnetic ion exchange resin(MIEX)adsorption and Ti-PbO2 electrode electrolysis.The effects of initial concentration of reactant,coexistence inorganic anions,cations,humic acid concentrations and initial pH in aqueous solution on adsorption rate were discussed,and the adsorption properties of MIEX resin were illuminated.The effects of target pollutants initial concentration,electrolyte type,electrolyte concentration,ampere density and initial pH on degradation rate were stuied.The result shows:(1)Humic acid and anions will inhibit adsorption TBBPA and TBP,and the inhibitory effect will enhanced when the concentration increase.Less than 10 mg/L of Ca2+,Mg2+will promote adsorption of TBBPA,but continue to increase the concentration it will be inhibited;The exist of cations will accelerate adsorption of TBP.(2)The maximum adsorption rate of TBBPA was 74.3% when pH=6.13,and adsorption of TBP was 93.3% when pH=7.80.The desorption rate of TBBPA and TBP is better with 0.1mol/L NaCl.(3)The adsorption kinetics process of TBBPA and TBP are well described by pseudo-second order kinetic model,the adsorption equilibrium process are more suitable described by Langmuir model,the dynamic adsorption process are more suitable described by Thomas model and Yoon-Nelson model;temperature increment will promote adsorption of TBP,but inhibit the adsorption of TBBPA.(4)The degradation process of TBBPA and TBP with Ti-PbO2 electrode conform to first order kinetic model.The degradation rate was negatively correlated with pollutants initial concentration.The degradation rate increases with the ampere density increase,when the current density is 0~15 mA/cm2.The best degradation effect of TBPPA and TBP with 5mmol/L sodium sulfate electrolyte,the relationship between degradation rate andconcentrations are the mountain type.(5)The related factors order impact on degradation TBBPA and TBP: current density>p H>initial concentration>electrolyte concentration,the best degradation efficiency of TBBPA was 97.02% when pH=7.62 and TBP was 97.27% when pH=6.51.