摘要：

Cr（Ⅵ）-染料复合污染废水在印染、制革等工业生产活动中普遍存在。基于“以废治废”的理念，利用水体中的Cr（Ⅵ）活化工业废物亚硫酸盐〔Cr（Ⅵ）/S（Ⅳ）体系〕，探究其同步去除罗丹明B（RhB）和Cr（Ⅵ）的可行性，鉴别了反应体系中的活性物种，并考察了Na₂SO₃和Cr（Ⅵ）的初始浓度、反应溶液初始pH以及溶解氧对RhB和Cr（Ⅵ）降解效果的影响。结果表明：在pH_ini=3时，1.00 mmol/L Na₂SO₃和0.15 mmol/L Cr（Ⅵ）在60 min内可去除95.1%的RhB和87.4%的Cr（Ⅵ）。溶解氧参与了反应过程中硫氧自由基的转化，对RhB的降解以及Cr（Ⅵ）的还原发挥着关键作用。猝灭实验和EPR测试结果表明，SO₄ ^·-、SO₅ ^·-、·OH和¹O₂共同参与了Cr（Ⅵ）/S（Ⅳ）体系的反应过程，其中SO₄ ^·-是主要的活性物种，由SO₄ ^·-生成的¹O₂对RhB降解的贡献也不容忽视。通过紫外全波长扫描和GC/MS分析结果推测了RhB可能的降解路径。

关键词: 亚硫酸盐, 高级氧化法, 自由基, 印染废水

Abstract:

The wastewater containing both Cr（Ⅵ） and dyes is frequently produced in the industrial manufacturing processes including printing and dyeing，tanning，etc. Based on the concept of “treating waste with waste”，the feasibility of simultaneous removal of Rhodamine B（RhB） and Cr（Ⅵ） by activating sulfite with Cr（Ⅵ）（Cr（Ⅵ）/S（Ⅳ） system） was investigated. The active species in the reaction system were identified，and the effects of initial concentrations of Na₂SO₃ and Cr（Ⅵ），the initial pHand the amount of dissolved oxygen on the degradation of RhB and Cr（Ⅵ） were investigated. The results showed that，at the initial pH was 3，95.1% of RhB and 87.4% of Cr（Ⅵ） was removed within 60 min by 1.00 mmol/L Na₂SO₃ and 0.15 mmol/L Cr（Ⅵ）. The dissolved oxygen was involved in the conversion of sulfur-oxygen free radicals in the reaction process，and played a key role in the degradation of RhB and the reduction of Cr（Ⅵ）. The finding of EPR detection and quenching experiments demonstrated that，SO₄ ^·-，SO₅ ^·-，·OH and ¹O₂ cooperatively engaged in the reaction process of Cr（Ⅵ）/S（Ⅳ） system，in which SO₄ ^·-is the main active species. Meanwhile，the contribution of ¹O₂ formed from SO₄ ^·-should not be ignored. In addition，the possible degradation pathway of RhB was proposed according to the results of ultraviolet full-wavelength scanning and GC/MS.

Key words: sulfite, advanced oxidation process, radical, printing and dyeing wastewater

中图分类号: 

• X703.1