钢渣活化过一硫酸盐氧化法深度处理焦化废水

Advanced treatment of coking wastewater by steel slag activated peroxymonosulfate oxidation process

采用钢渣活化过一硫酸盐(PMS)氧化法深度处理焦化废水生化出水,研究了钢渣加入量、PMS浓度和初始p H对该废水处理效果的影响,考察了钢渣的重复利用性能,分析了钢渣-PMS氧化处理前后废水中有机物和急性毒性的变化。实验结果表明:在钢渣加入量5 g/L、PMS浓度7 mmol/L、初始p H 8.1、反应时间3 h的条件下,废水中色度和COD去除率分别为82.99%和62.89%,出水毒性变小;钢渣重复使用5次后,COD去除率降低至38.73%。钢渣-PMS体系氧化降解有机污染物的途径可能有两种:一种是钢渣中的CaO水解使溶液呈碱性,活化PMS生成了O_(2)^(-)·和^(1)O_(2);另一种是钢渣中的铁氧化物活化PMS生成SO_(4)^(-)·和·OH。三维荧光光谱分析结果表明,钢渣活化PMS所产生的活性物种可以有效破坏废水中的芳香蛋白类物质、腐殖酸类物质和溶解性微生物代谢产物。

The bio-treated coking wastewater was treated by steel slag activated peroxymonosulfate(PMS)oxidation process.The effects of steel slag dosage,PMS concentration and initial pH on the treatment of the wastewater were studied.The reusability of steel slag was investigated.The changes of organic compounds and acute toxicity in the wastewater before and after steel slag-PMS oxidation treatment were analyzed.The experimental results show that:Under the conditions of steel slag amount 5 g/L,PMS concentration 7 mmol/L,initial pH 8.1 and reaction time 3 h,the removal rate of chroma and COD is 82.99%and 62.89%,respectively,and the toxicity of the effluent is weakened;After 5 times of reuse of steel slag,the COD removal rate decreases to 38.73%.There are two possible ways to degrade organic pollutants by oxidation of steel slag-PMS system:One is that CaO in steel slag hydrolyzes to make the solution alkaline,activating PMS to generate O_(2)^(-)·and^(1)O_(2);The other is that iron oxide in steel slag activates PMS to generate SO_(4)^(-)·and·OH.The analysis results of three-dimensional fluorescence spectroscopy showed that the active species produced by steel slag activated PMS can effectively destroy aromatic proteins,humic acids and soluble microbial metabolites in the wastewater.