紫外光催化H_2O_2降解SCN^-的研究

Degradation of Tiocyanate by UV/H_2O_2 Process

研究不同条件下紫外光催化H_2O_2降解SCN-的效果。结果表明,在光照强度9. 94 m W/cm^2,pH值为7,H_2O_2浓度2. 25 mmol/L,温度30℃,反应时间120 min的条件下,100 mg/L SCN^-基本得到降解,SCN^-去除率为96. 88%,出水中残余的SCN^-,TOC和CN^-质量浓度分别为3. 12 mg/L,3. 856 mg/L和0. 936mg/L。H_2O_25 mmol/L,出水中CN^-质量浓度为0. 134 mg/L,能满足新的炼焦化学工业污染物排放标准(GB16171—2012)。紫外光催化H_2O_2降解SCN^-过程中氮元素很少转化为NO_3^-和NO_2,主要转化为CN^-和NH_4^+-N;硫经降解生成SO_4^(2-)。

The degradation effect of SCN^-is investigated by using UV irradiation after the addition of hydrogen peroxide(H2O2)in different condition.It is found that the removal rate of SCN^-is 96.88%under SCN^-initial concentration of 100 mg/L,light intensity of 9.94 mW/cm^2,initial pH of 7,H2O2 concentration of 2.25 mmol/L,reaction temperature of 30℃,reaction time of 120 min,and the concentration of SCN^-,TOC and CN^-of effluent is 3.12 mg/L,3.856 mg/L and 0.936 mg/L respectively.The concentration of CN^-is 0.134 mg/L under H2O2 5 mmol/L meeting the emission standard of pollutants for coking chemical industry(GB 16171-2012).Additionally,the nitrogen element is rarely converted to NO3^-and NO2^-,but converted to other forms of nitrogen,and sulfur element is converted to SO4^2-.