Wang Jun, Wen Xiaocui, Jiang Shaojun, Chen Tao
Fankou Lead-Zinc Mine, Shenzhen Zhongjin Lingnan Non-Ferrous Metal Company Limited, Shaoguan 512000, China.
School of Environment, South China Normal University, University Town, Guangzhou 510006, China.
Polymers (Basel). 2022 Jul 21;14(14):2959. doi: 10.3390/polym14142959.
Inappropriate disposal of leaching residues from the lead-zinc tailings recovery process may result in environmental pollution. Its recycling and reuse remain a prevalent topic in environmental science and technology. It was roasted to prepare leaching residues-based materials (TLRS) in this work, and the TLRS were creatively used as the catalyst to active sodium persulfate (PS) to degrade organic pollutants. Degradation of tetracycline using the TLRS-PS system was evaluated, and the treating parameters were optimized. Roasting resulted in the exposure of active sites on TLRS surface, in which transition metals can donate electrons to PS to form SO. SO can further react with OH to form ·OH. Formation of these radicals was confirmed by both quenching experiments and EPR analysis. Under optimized conditions, 85% of the TC can be degraded in 3.0 h, and ~50% of degraded TC was mineralized to CO and HO. The performance of TLRS barely changed after four reuses, suggesting the chemical stability of TLRS. The presence of dissolved substance in the water matrix could weaken the performance of the TLRS-PS system. A mechanism of TC degradation was proposed based on the experimental results and literature. These preliminary results provide us new insight on the reuse of lead-zinc flotation tailings.
铅锌尾矿回收过程中浸出残渣的不当处置可能导致环境污染。其回收再利用仍是环境科学与技术领域的一个热门话题。在本研究中，通过焙烧制备了基于浸出残渣的材料（TLRS），并创新性地将TLRS用作活化过硫酸钠（PS）降解有机污染物的催化剂。评估了使用TLRS-PS体系降解四环素的效果，并对处理参数进行了优化。焙烧使TLRS表面的活性位点暴露，其中过渡金属可向PS提供电子形成SO。SO可进一步与OH反应形成·OH。淬灭实验和电子顺磁共振分析均证实了这些自由基的形成。在优化条件下，3.0小时内可降解85%的四环素，约50%降解的四环素矿化为CO和HO。TLRS经过四次重复使用后性能几乎没有变化，表明TLRS具有化学稳定性。水基质中溶解物质的存在会削弱TLRS-PS体系的性能。基于实验结果和文献提出了四环素降解的机制。这些初步结果为铅锌浮选尾矿的再利用提供了新的见解。
