湿法脱硫废水多污染物深度净化及作用机制

李正超; 张燕玲; 詹道平; 赵鹏; 田森林; 刘树根

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中国环境科学 ›› 2025, Vol. 45 ›› Issue (6) : 3073-3083.

水污染与控制

湿法脱硫废水多污染物深度净化及作用机制

李正超¹, 张燕玲², 詹道平³, 赵鹏², 田森林¹, 刘树根¹

作者信息 +

Deep purification for multiple pollutants in wet desulphurization wastewater

LI Zheng-chao¹, ZHANG Yan-ling², ZHAN Dao-ping³, ZHAO Peng², TIAN Sen-lin¹, LIU Shu-gen¹

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文章历史 +

摘要

本研究采用沉淀-吹脱-电解工艺技术处理石灰石湿法脱硫废水,考察了工艺条件对除氯、脱氮、有机污染物去除的影响,并探究多污染物去除机制.基于RSM试验方法优化了复盐沉淀除氯工艺条件,在Ca/Al/Cl比例6.8:1.9:1、操作温度37.5℃条件下,脱硫废水中氯离子去除率为66.9%;碱性条件下空气吹脱处理,氨氮去除率为76.5%;再经电化学氧化处理180min,水体中氨氮和难降解有机物明显下降,出水氨氮和COD浓度分别降低至7mg/L与165mg/L.脱硫废水中投加钙铝复盐后,较高Ca/Al比以及适宜的反应温度促进四面体Al(OH)₄^-向Ca-O-Al八面体骨架转化,Cl^-通过吸附或离子交换这类途径与钙铝双金属层状氢氧化物结合,生成固相物Ca₄Al₂(OH)₁₂Cl₂•10H₂O并从水体沉淀析出;沉淀-吹脱处理后的尾水氯离子含量较高,在电化学作用下激发产生•Cl、•OH、¹O₂,水体中氨氮和难降解有机物通过阳极直接氧化与活性物质间接氧化得以高效净化.

Abstract

This study implemented an integrated precipitation-air stripping-electrochemical oxidation process to treat limestone wet desulfurization wastewater, systematically investigating the effects of operational parameters on chloride removal, nitrogen elimination, and organic pollutant degradation. The removal mechanisms of multiple contaminants were comprehensively elucidated. Through response surface methodology (RSM) optimization, the salt precipitation achieved 66.9% chloride ion removal efficiency under optimal conditions (Ca/Al/Cl molar ratio of 6.8:1.9:1, operational temperature 37.5℃). Air stripping was conducted under alkaline condition, which attained 76.5% ammonia nitrogen removal efficiency. Finally, after 180min electrochemical oxidation, the effluent ammonia nitrogen and COD concentrations were significantly reduced to 7mg/Land 165mg/L, respectively. Mechanistic analysis revealed that the introduction of calcium-aluminum salts facilitated the transformation of tetrahedral Al(OH)₄^- into Ca-O-Al octahedral under high Ca/Al ratios and appropriate thermal conditions. Cl^- were immobilized through adsorption or ion exchange by calcium-aluminum bimetallic layered hydroxide, then the Ca₄Al₂(OH)₁₂Cl₂•10H₂O was formed and precipitated from the water. After precipitation-air stripping process, the residual Cl^- concentration in the effluent was high, enabling its participation in electrochemical activation, and generating reactive species such as •Cl, •OH and ¹O₂, Thus those pollutants such as ammonia nitrogen and organic matters in the effluent was efficiently purified by direct anodic oxidation and indirect oxidation of active substances.

导出引用

李正超, 张燕玲, 詹道平, 赵鹏, 田森林, 刘树根. 湿法脱硫废水多污染物深度净化及作用机制[J]. 中国环境科学. 2025, 45(6): 3073-3083

LI Zheng-chao, ZHANG Yan-ling, ZHAN Dao-ping, ZHAO Peng, TIAN Sen-lin, LIU Shu-gen. Deep purification for multiple pollutants in wet desulphurization wastewater[J]. China Environmental Science. 2025, 45(6): 3073-3083

中图分类号： X703

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