光电催化降解印染废水的羟基自由基机理研究

STUDIES ON HYDROXYL RADICAL MECHANISM OF DYEING WASTEWATER DEGRADATION BY PHOTO-ELECTRO CATALYSIS

光电协同催化的主要作用原理为羟基自由基机理,但羟基自由基的分析较为困难。以水杨酸为分子探针,以分光光度法对光电协同催化处理印染废水过程中的羟基自由基进行测定,通过改变光照时间、光照强度、外加电压和pH进行试验。结果表明,光电催化降解酸性紫红比单独的光催化和电催化效果好;.OH是酸性紫红降解的主要因素。水杨酸分子探针浓度升高时,酸性紫红的脱色率相应减少;一定的光照时间内.OH生成量与时间成正比关系;光照强度增大,羟基自由基产生量也相应增加;外加电压10 V,pH为6～8时.OH有较高的生成量。

The influences of high-voltage electrostatic field on the scale inhibition performance of polyepoxysuccininc acid （PESA） and the crystal forms of scale were investigated. The results of the static scale inhibition experiments show that synergistic scale inhibition effect is obviously exist at the electrostatic field and PESA. When the electrostatic field is 5 000 V and the dosage of PESA is 6 mg/L, the rate of static scale inhibition is 95.4%, which is 22.3% higher than that in the non-electrostatically treated water sample. The results of SEM and XRD show that the content of aragonite in the deposited sample is increased, which indicate the electrostatic field is advantageous to the aragonite generation.