Real textile effluent degradation assisted by Fe/PVA and magnetic waste

ABSTRACT Organic compounds present on industrial wastes are mostly resistant to conventional biological and chemical treatments. Textile industry has presented several environmental problems mainly related to the use and management of water resources. It has a high consumption of potable and underground water in its processes. These wastewaters are one of the most polluting of the industrial area. The Advanced Oxidation Process AOPs allow to decompose organic matter in a non-selectively way by the attack of •OH radicals. This work presents the characterization and application of several catalysts for real textile effluent treatment (from an industry dedicated to dyeing and finishing clothes; in Buenos Aires province).Three different iron catalysts are used: 1º) Synthesized in a laboratory, 2º) Waste from metallurgic industry and 3º) commercial steel wool. These are characterized using SEM/EDX. The effluent is characterized before and after treatment, where the degradation is following by measure of % COD, pH and Fe2+ content in solution by condition different of treatment. The effect of catalysts on the applied treatment is studied, which consists of an oxidation of organic matter by action of Fe species and H2O2 in solution, assuming a Fenton process a pH neutral. The results show that the three catalysts are efficient for use in the process of degradation of the real textile effluent. In all cases, the COD final values are suitable for discharge into a sewer system.

摘要：工业废弃物中所含的有机化合物大多难以通过常规生物与化学处理手段实现降解。纺织行业已引发诸多环境问题，其核心矛盾集中于水资源的使用与管理层面。该行业生产过程中消耗大量饮用水与地下水，所产生的废水是工业领域污染最为严重的废水类型之一。高级氧化工艺（Advanced Oxidation Processes, AOPs）可通过羟基自由基（•OH）的氧化攻击，无选择性地分解有机物质。本研究针对布宜诺斯艾利斯省某专注于衣物染色与整理的纺织厂产生的实际纺织废水，开展了多款催化剂的表征与应用研究。本次实验采用三种不同的铁基催化剂：1）实验室合成型催化剂；2）冶金工业废弃物型催化剂；3）商用钢丝棉。采用扫描电子显微镜/能量色散X射线光谱仪（SEM/EDX）对上述三类催化剂进行表征。分别对处理前后的纺织废水开展表征工作，通过设置不同处理条件，以化学需氧量（Chemical Oxygen Demand, COD）去除率、溶液pH值及二价铁离子（Fe²+）浓度为监测指标，追踪有机物质的降解进程。本研究探究了催化剂对该处理工艺的影响：该工艺借助溶液中铁物种与过氧化氢（H₂O₂）的氧化作用实现有机物质降解，近似为中性pH条件下的芬顿（Fenton）反应过程。实验结果表明，三种催化剂均可有效应用于实际纺织废水的降解工艺。所有实验组的最终化学需氧量值均符合市政污水管网的排放要求。