钢铁涂层液含铬废水处理零排放工艺的应用研究

Application study of zero discharge process in treatment of chromium-containing wastewater from steel coating solution

摘要

实现钢铁涂层行业含铬废水零排放是破解环保瓶颈与资源约束的关键。本文系统研究了集成预处理、深度除铬、高效浓缩与末端固化的零排放工艺链。通过沙钢扬子江冷轧工程实例验证（规模480 m³/d），表明“化学氧化还原沉淀→高级解毒氧化→接触氧化生物降解→纳滤膜分盐→高压反渗透→三效蒸发结晶”组合工艺可实现全流程零排放：出水回用率≥97%，回用水满足工业回用标准，含铬污泥经稳定化后浸出毒性低于国家标准限值。技术经济分析显示吨水处理成本约28.5元，铬资源回收可降低综合成本18%-25%。研究表明，分质资源化与多级屏障控制是实现环境效益与经济效益平衡的核心路径。

Abstract

Achieving zero discharge of chromium containing wastewater in the steel coating industry is the key to solving environmental bottlenecks and resource constraints. This article systematically studies the zero emission process chain that integrates pretreatment, deep chromium removal, efficient concentration, and end solidification. Through the verification of the Yangzijiang Cold Rolling Project at Shagang (with a scale of 480 m³/d), it is shown that the combination process of “chemical oxidation-reduction precipitation → advanced detoxification oxidation → contact oxidation biodegradation → nanofiltration membrane salt separation → high-pressure reverse osmosis → three effect evaporation crystallization” can achieve zero emissions throughout the entire process: the effluent reuse rate is ≥ 97%, the reuse water meets industrial reuse standards, and the leaching toxicity of chromium containing sludge after stabilization is lower than the national standard limit. Technical and economic analysis shows that the cost of treating one ton of water is about 28.5 yuan, and chromium resource recovery can reduce the overall cost by 18%-25%. Research has shown that qualitative resource utilization and multi-level barrier control are the core paths to achieve a balance between environmental and economic benefits.

关键词

含铬废水 / 零排放 / 资源回收 / 分盐结晶 / 蒸发固化

Key words

chromium containing wastewater / Zero emissions / recycling / Salt crystallization / Evaporative solidification

参考文献

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