Abstract:

Coke powder is a low-value by-product of coking/coal industries, and the use of coke powder as a pollution control material is an important field for its high-value application. The morphology and elemental composition of coke powder were characterized. The performance of persulfate activated by coke powder was evaluated by the removal efficiency of aniline. The characterization results showed that the coke powder had a rough surface with a pore structure. The activity test results presented that 5mmol/L persulfate could be efficiently activated by 1g/L coke powder, and more than 99% aniline (20mg/L) was degraded after 120min. The ash in CP did not contribute to aniline degradation. The degradation efficiency of aniline could be improved by increasing coke powder dosage and persulfate concentration. Moreover, coke powder could efficiently activate persulfate to degrade aniline in the range of pH 3—11, and the aniline degradation efficiency could be maintained above 83%. Meanwhile, aniline degradation in the system was maintained above 90% in the presence of Cl^-, HCO{}_{\mathrm{3}}^{-} or SO{}_{\mathrm{4}}^{\mathrm{2}-}, indicating that coke powder had the potential to be used to repair organic pollutants in complex wastewater. Response surface analysis showed that coke powder could efficiently activate persulfate to degrade aniline, and the interaction between coke powder dosage and persulfate concentration was strong, both of which contributed to the degradation efficiency of aniline. Furthermore, free radical quenching tests proved that O{}_{\mathrm{2}}^{·-} and ·OH were the dominant radicals generated in the system of coke powder with persulfate. The findings can provide guidance for the high-value application of low-value coal-based by-products, and provide new opportunities for the further development of environmentally friendly wastewater pollution control and resource utilization technologies.

Key words: coke powder, aniline, pollution control, persulfate activation

摘要：

焦粉作为焦化/煤化企业的低附加值副产物，用作污染控制材料是其高价值应用的一条重要途径。本文对焦粉形貌与成分进行表征分析，通过苯胺降解动力学和影响因素之间的交互作用评估焦粉活化过硫酸盐的催化性能，并初步探讨了相关机理。表征结果显示焦粉表面粗糙，有清晰的孔隙。活性测试结果显示，1g/L焦粉可以高效活化5mmol/L过硫酸盐降解20mg/L苯胺，反应120min后苯胺去除率高于99%，其中灰分对苯胺降解无贡献。增加焦粉剂量和过硫酸盐浓度均可提高苯胺的降解效率。焦粉在pH 3~11范围内均可高效活化过硫酸盐降解苯胺，去除率维持在83%以上。此外，焦粉具有应用于修复复杂水体中有机污染物的潜能，在Cl^-、HCO{}_{\mathrm{3}}^{-}和SO{}_{\mathrm{4}}^{\mathrm{2}-}干扰下，体系中苯胺去除率维持在90%以上。响应曲面分析表明，焦粉可以高效活化过硫酸盐降解苯胺，且焦粉剂量与过硫酸钠浓度的交互作用强，二者决定了苯胺的最终去除率。自由基淬灭实验证明焦粉活化过硫酸盐降解苯胺过程中，主要产生的活性氧物种为O{}_{\mathrm{2}}^{·-}和·OH。本文的研究结果可为低附加值的煤基副产物高价值应用提供指导，并为进一步发展环境友好的水污染控制与资源化技术提供新契机。

关键词: 焦粉, 焦化废水, 污染控制, 活化过硫酸盐