摘要：

以焦化尾水为处理对象, 用Fe²⁺活化S₂O₈^2- 产生的强氧化性硫酸根自由基对其进行处理, 探讨了初始pH,Fe²⁺和S₂O₈^2- 投加量对焦化尾水脱色率和COD去除率的影响, 并在此基础上进行了正交实验。结果表明:各因素对焦化尾水脱色率和COD去除率影响大小的顺序为n(Fe²⁺)/n(S₂O₈^2-)>pH>c(S₂O₈^2-);相应的优化条件:pH=3.0,c(S₂O₈^2-)=28 mmol/L,n(Fe²⁺)/n(S₂O₈^2-)=0.45.在此优化条件下, 处理COD为145~172 mg/L的焦化尾水, 常温下反应120 min时, 脱色率和COD去除率分别可达89.4%、68.5%.UV-vis分析表明, 尾水中的芳香族化合物、多环芳烃等难降解有机物结构易于被破坏, 但难以进一步矿化。

关键词: 硫酸根自由基, 焦化尾水, 高级氧化

Abstract:

Taking coking biological treated effluent as treated object, it has been treated with strong oxidizing sulfate radicals generated from S₂O₈^2- with Fe²⁺ by activation. The effects of initial pH, dosage of Fe²⁺ and S₂O₈^2- on the decolorization and COD removing rates of coking biological treated effluent are investigated, and an orthogonal experiment is carried out on the basis of the previous studies. The results show that the sequence order of influence degree on the decolorization and COD removing rates is as follows:n(Fe²⁺)/n(S₂O₈^2-)>pH>c(S₂O₈^2-). The correspo- nding optimized conditions of the factors are as follows:pH=3.0, c(S₂O₈^2-)=28 mmol/L and n(Fe²⁺)/n(S₂O₈^2-)=0.45. Under these optimized conditions, the coking biological treated effluent whose COD is 145-172 mg/L should be treated. Its decolorization and COD removing rates can reach 89.4% and 68.5%, respectively, when the temperature is normal and reaction time 120 min. UV-vis analysis shows that the structure of aromatic compounds, polycyclic aromatic hydrocarbons and other refractory organic compounds are prone to be destroyed, but difficult to be further mineralized.

Key words: sulfate radicals, coking biological treated effluent, advanced oxidation

中图分类号: 

• X703.5