紫外/过硫酸盐工艺降解水中氯贝酸的研究

Kinetics of clofibric acid degradation by UV/persulfate system in aqueous solution

采用紫外/过硫酸盐(UV/PS)工艺去除水中典型PPCPs类物质氯贝酸(CA).考察了氯贝酸初始浓度?PS投加量?溶液初始p H值?碳酸氢根离子浓度、氯离子浓度和腐殖酸(HA)投加量共计6种因素对UV/PS工艺去除氯贝酸的影响.结果表明:UV/PS工艺降解氯贝酸与准一级动力学模型相符(R2>0.95),准一级反应速率常数随氯贝酸初始浓度增加而减小.在一定的范围内,随着PS投加量的增加,氯贝酸的降解速率快速增加.不同的p H值环境对氯贝酸的降解有一定影响,溶液p H值从酸性到碱性再到强碱性的过程中,UV/PS工艺对氯贝酸的降解速率呈先加快后减慢的趋势.溶液中的碳酸氢根离子和氯离子都会对UV/PS工艺降解氯贝酸产生抑制作用,且两者对该反应的抑制作用大小关系为HCO3->Cl-.HA的存在对UV/PS工艺去除氯贝酸有抑制作用.

UV/PS process was employed to remove clofibric acid （CA）, one of the typical pharmaceuticals and personal care products. The effect of six kinds of factors （initial concentration of CA, persulfate dosage, initial pH, concentration of bicarbonate, chloride and humic acid） on the kinetics of CA removal by UV/PS process was investigated. CA degradation fitted well with the pseudo-first-order kinetics （R2〉0.95）. The pseudo-first-order-constant was decreased with the increase of the initial CA concentration. Meanwhile, the degradation rate of CA was increased with the increase of the PS dosage in a certain range. Different pH environment had certain effect on the degradation of CA. When the pH was changed from acidic to alkaline and then to strong alkaline, the degradation rate of CA had a tendency to elevate and drop. Bicarbonate or chloride inhibited the degradation of CA, and the inhibition extent was in the order of HCO3？〉Cl？. The presence of humic acid also retarded the removal of CA to a certain extent.