Electrochemical advanced oxidation processes (EAOPs) based on hydroxyl radicals (OH) have some limitations when they are applied to real wastewater treatment, such like strict requirements on pH (acidic electrolyte) and high energy consumption. Compared to OH, Sulfate radicals (SO₄^–) have high redox potential in wider range of pH (2–9). In this study, SO₄^– were efficiently produced by electrochemical activation of SO₄²⁻ at boron doped diamond (BDD) anode. The degradation rate of 2,4-DCP (k = 0.828 ± 0.05 h⁻¹) in the presence of Na₂SO₄ was approximately 4 times than that without Na₂SO₄ (k = 0.219 ± 0.01 h⁻¹), indicating that SO₄^– exhibited higher reactivity than OH at initial pH = 9. Moreover, the amount of O₂ decreased by 65% after 100 min during electro-oxidation of 2,4-DCP and the specific energy consumption per unit TOC (EC_TOC) was reduced by 70% when the concentration of Na₂SO₄ increased from 0.01 to 0.1 M. The impact of sulfate ions in the electrochemical advanced oxidation were investigated. Electron spin resonance (ESR) measurements were conducted to identify the formation of SO₄^–. Electrolysis of 2,4-DCP with specific radical scavengers (ethanol and tert-Butanol) were conducted and the results revealed that SO₄^– were mainly produced by one-electron loss of sulfate at basic condition. Electro-generation persulfate was measured and participation of non-radical activation of persulfate was investigated. O₂ production was quantified and we found electrochemical activation of sulfate could inhibit water dissociation. Taken all findings, a mechanism of electrochemical activation of sulfate at BDD anode was summarized. This technology eliminates the requirement for pH adjustment for wastewater treatment and makes EAOPs more effective and economic as well.

基于羟基自由基（OH）的电化学高级氧化工艺（EAOP）在将其应用于实际废水处理时有一些局限性，例如对pH（酸性电解质）的严格要求和高能耗。相比OH，硫酸盐基团（SO ₄ ^- ）具有在更宽的pH范围（2-9）的高氧化还原电位。在这项研究中，SO ₄ ^–是通过在硼掺杂金刚石（BDD）阳极上通过电化学活化SO ₄ ^2-的方式有效产生的。2,4-DCP的降解速率（K = 0.828±0.05ħ ^-1的Na存在下）₂ SO ₄为约大于4次无钠₂ SO₄（k = 0.219±0.01 h ^-1），表明在初始pH = 9时SO ₄ ^–表现出比OH高的反应性。此外，在2,4的电氧化过程中，100分钟后，O _2的含量降低了65％。当Na ₂ SO ₄的浓度从0.01 M增加到0.1 M时，-DCP和每单位TOC的单位能耗（EC _TOC）降低了70％。研究了硫酸根离子对电化学高级氧化的影响。进行了电子自旋共振（ESR）测量，以确定SO ₄ ^–的形成。。2,4-DCP具有特定的自由基清除剂（乙醇和叔丁醇）的电解中进行，并且该结果显示出SO ₄ ^-主要是由在碱性条件下的硫酸单电子损失产生的。测量了过硫酸盐的发电量，并研究了过硫酸盐的非自由基活化作用。量化了O _2的产生，我们发现硫酸盐的电化学活化可以抑制水的离解。综合所有发现，总结了BDD阳极硫酸盐电化学活化的机理。该技术消除了废水处理中调节pH的要求，并使EAOP更加有效和经济。