Integration of treatment technologies with Fenton reagent for laboratory effluent remediation

Abstract This study investigated of the potential value of the integration of the coagulation/flocculation, Advanced Oxidation Processes (AOP) (Fenton reagent) and slow sand filtration technologies, with the aim of treating laboratory wastewater. The treatment system was designed in laboratory scale through coagulation/flocculation. It involved the use of Jar Test equipment with a sequence of two rotational phases: fast mixes to 300 rpm for 20 seconds and slow mixes to 30 rpm for 6 minutes and 10 seconds, with the addition of anionic polymer and sedimentation for 60 minutes at ambient temperature. In the treatment via Fenton reagent, two rotational phases were used: rapid mixing at 300 rpm for 20 seconds with the addition of iron (Fe2+) and slow mixing at 30 rpm for 6 minutes and 10 seconds with the addition of hydrogen peroxide, followed by 60 minutes of sedimentation at ambient temperature. A cylindrical tank of polyvinyl chloride, sands and non-woven synthetic fabrics were used in the slow filtration. The filtration rate adopted was 3 m3 m-2 d-1 with a hydraulic retention time of 264 minutes. The best concentrations of chemical reagents used in the treatments were: 0.80 mg L-1 of polymeric anionic, 200.00 mg L-1 of H2O2 and 13.00 mg L-1 of total soluble iron. The integration of the treatment technologies made it possible to achieve a removal rate of 75.27% of COD and 94.12% of total phenols. Furthermore, the conjugation of the processes allowed the removal of 87.58% of TOC.

摘要 本研究探究了混凝-絮凝、高级氧化工艺（Advanced Oxidation Processes, AOP）（芬顿试剂法）与慢砂过滤技术联用的潜在应用价值，旨在处理实验室废水。本研究设计了实验室规模的联用处理系统：其中混凝-絮凝工序采用烧杯试验装置，包含两段搅拌流程——先以300 rpm快速搅拌20秒，再以30 rpm慢速搅拌6分10秒，期间投加阴离子聚合物，随后在室温下静置沉降60分钟；芬顿试剂处理环节采用两段搅拌流程：先投加亚铁离子（Fe²+）并以300 rpm快速搅拌20秒，再投加过氧化氢并以30 rpm慢速搅拌6分10秒，随后在室温下静置沉降60分钟；慢砂过滤装置采用聚氯乙烯（polyvinyl chloride, PVC）圆柱槽、砂料与非织造合成织物搭建，采用的过滤速率为3 m³·m⁻²·d⁻¹，水力停留时间为264分钟。本研究确定了各处理工序的最优药剂投加浓度：阴离子聚合物0.80 mg·L⁻¹、过氧化氢200.00 mg·L⁻¹、总可溶性铁13.00 mg·L⁻¹。该联用处理技术可实现75.27%的化学需氧量（Chemical Oxygen Demand, COD）去除率与94.12%的总酚去除率，此外该工艺组合还可实现87.58%的总有机碳（Total Organic Carbon, TOC）去除。