二价铁催化过碳酸钠处理水中乙苯

摘要

Ethylbenzene (EB) degradationperformance in Fe (Ⅱ) activated sodium percarbonate (SPC) system was investigated in this study. The effects of various factors, such as the initial SPC and Fe (Ⅱ) concentrations, anions (Cl-, HCO3-, SO42-, and NO3-) concentration, natural organic matters (NOM), and initial solution pH were evaluated. The results showed that EB (1mmol/L) could be degraded completely in 20min with both SPC and Fe (Ⅱ) dosages of 12mmol/L. Both Cl- and HCO3- anions and NOM had significant inhibitive effect on EB degradation, while the influence of SO42- and NO3- was negligible at the tested ionic strength ranges. The EB removal was still significant at the initial solution pH of 9 even though the degradation of EB decreased with the increasing of initial solution pH (from 3.0 to 11.0), suggesting that Fe(Ⅱ) activated SPC process was an effective technique for EB degradation at a wider pH range. In addition, the results of free radical probe tests and free radical scavenger tests indicated that?OH was the predominant species responsible for EB degradation even though both?OH and O2?- were generated in the SPC-Fe(Ⅱ) system.%采用Fe(Ⅱ)催化过碳酸钠(SPC)体系处理水溶液中的乙苯(EB),考察c(SPC)、c(Fe(Ⅱ))、阴离子浓度、天然有机物(NOM)以及溶液初始pH值对EB降解效果的影响,并确定EB降解过程中起主导作用的自由基.结果表明,对于浓度为1mmol/L的EB溶液,c(SPC)、c(Fe(Ⅱ))均为12mmol/L时,20min内EB可被完全去除;Cl-、HCO3-、NOM的存在均会抑制EB降解,SO42-和NO3-对EB降解无影响;溶液初始pH值(pH3.00~11.00)越高,EB去除率越低,但当pH=9时,降解效果仍很显著,表明该体系能够在较宽pH值范围内高效降解水溶液中EB;自由基探针试验证实体系中存在?OH和O2?-,自由基清扫试验表明?OH对EB降解起主导作用.