周期换向电解过程中羟基自由基的产生及测定

羟自由基(·OH)氧化是电解氧化技术的重要机理之一,采用清水实验(0.015 mol/L的Na2SO4溶液)探索了周期换向电解过程中.OH的产生机理,筛选了.OH的检测方法,并研究了.OH产生量的影响因素.结果表明,以二甲亚砜(DMSO)为捕捉剂的比色法其检测效果优于以水杨酸为捕捉剂的比色法,在电压为8 V,换向周期10s的条件下反应90min时,50mL200mmol/L的DMSO可以捕捉羟自由基的量达到最大值.同时得出添加H2O2时羟自由基累积量提高的幅度大于添加H2SO4,表明可以将周期换向电解法与H2O2相结合,更广泛地将周期换向电解法应用到水处理领域.

Generation and Determination of Hydroxyl Radicals from Electrolytic Process with Periodically Reversing

The oxidation of free hydroxyl radicals (·OH) is one of the most important mechanisms for the electrolysis oxidation technology. The generation mechanism of producing ·OH in periodically reversing electrolysis process was investigated in the 0.015 mol/L Na2SO4 solution and the detective methods of ·OH were selected. Furthermore, the influence factors of the generation volume of ·OH were studied. The results showed that colorimetric analysis using dimethyl sulfoxide (DMSO) as the trapping agent was superior to that using salicylic acid as the trapping agent. The maximum amount of free hydroxyl radicals was detected when the volume of DMSO (200 mmol/L) was 50 mL, with the reaction voltage of 8?V, exchange period of 10 s and reaction time of 90 min. The cumulated amount of the free hydroxyl radicals by adding H2O2 increased more than that by adding H2SO4, indicating that the periodic reversing electrolysis method combined with adding H2O2 could be widely used in field of wastewater treatment.