Abstract:
The long-term and stable removal of thallium (Tl) from industrial wastewater generated by mining and smelting operations remains challenging. While sand filters are commonly applied for the simultaneous removal of Mn(II) and other heavy metals, they have limited efficacy in treating Tl-contaminated wastewater. To address this gap, we operated a lab-scale Mn sand filter (MF) without added microorganisms to investigate the efficiency and mechanisms of Mn(II) and Tl(I) removal. Trends in effluent Mn(II) and Tl(I) concentrations indicated three operational stages: start-up, developing and maturation. Over time, the removal efficiency of Tl(I) gradually improved, plateauing at approximately 80 % eventually. Throughout operation, Tl(I) was sequestrated via surface complexation and ion exchange. Besides, enrichment of Sphingobium and other typical manganese oxidizing microorganisms (MnOM) during operation facilitated Mn(II) and Tl(I) oxidation and sequestration by generating biogenic manganese oxides (BioMnOx). Additionally, the accurate control of water quality and operating conditions during operation could also enhance removal efficiency. In summary, physicochemical actions of Mn oxides and biochemical actions of microorganisms synergistically contributed to the sequestration of Mn(II) and Tl(I). These findings provided a novel and sustainable method for the long-term and stable treatment of industrial wastewater containing thallium.
摘要:
从采矿和冶炼操作产生的工业废水中长期稳定地去除铊(Tl)仍然具有挑战性。虽然砂滤器通常用于同时去除Mn(II)和其他重金属,它们在处理Tl污染的废水方面具有有限的功效。为了解决这个差距,我们在没有添加微生物的情况下操作了实验室规模的Mn砂过滤器(MF),以研究Mn(II)和Tl(I)去除的效率和机理。流出物Mn(II)和Tl(I)浓度的趋势表明三个操作阶段:启动,发育和成熟。随着时间的推移,Tl(I)的去除效率逐渐提高,最终达到约80%。在整个操作中,Tl(I)经由表面络合和离子交换而被螯合。此外,在操作过程中,狮身人面像和其他典型的锰氧化微生物(MnOM)的富集通过产生生物氧化锰(BioMnOx)促进了Mn(II)和Tl(I)的氧化和螯合。此外,在操作过程中准确控制水质和操作条件也可以提高去除效率。总之,Mn氧化物的物理化学作用和微生物的生化作用协同促进了Mn(II)和Tl(I)的螯合。这些发现为含th工业废水的长期稳定处理提供了一种新颖且可持续的方法。