Zuo Wenlu, Yu Yadong, Huang He
College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211800, People's Republic of China; School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210023, People's Republic of China.
College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211800, People's Republic of China.
Water Res. 2021 May 1;195:116984. doi: 10.1016/j.watres.2021.116984. Epub 2021 Feb 27.
Heavy metal contamination has received increasing attention as a growing worldwide environmental problem. Traditional remediation methods are mainly based on adsorption, precipitation and oxidation-reduction, which reduce the availability or toxicity of heavy metal ions. Microbe-photocatalyst hybrids (MPH), which behave as a semi-artificial photosynthetic system, integrate microbial cells with artificial photocatalysts for solar-to-chemical conversion. A few very recent studies indicate that MPH can be applied to treat organic contamination in water. Here, we propose a novel idea that MPH may also have great potential for solving heavy metal pollution. Heavy metals in wastewater could possibly be utilized to synthesize photocatalysts for MPH by microbial mineralization. Photo-induced electrons generated by photocatalysts in MPH can be transferred into microbial cells to promote intracellular enzymatic reductions, which allows heavy metal ions such as Cr and Se to be reduced and detoxified. Moreover, heavy metal ions like As and Sb can be used as sacrificial electron donors to maintain the continuous operation of the MPH, whereby these metal ions are simultaneously oxidized and detoxified. The excellent potential of MPH in the treatment of heavy metal-polluted wastewater is explained and a solution based on MPH is put forward as well as verified experimentally in this work. This solution can realize electron transfer between different metal ions to simultaneously remediate multiple heavy metal ions in wastewater. This finding may bring new hope for treating multiple heavy metal polluted wastewater in the future.
作为一个日益严重的全球性环境问题，重金属污染已受到越来越多的关注。传统的修复方法主要基于吸附、沉淀和氧化还原，这些方法降低了重金属离子的有效性或毒性。微生物-光催化剂杂化体（MPH）作为一种半人工光合系统，将微生物细胞与人工光催化剂结合用于太阳能到化学能的转化。最近的一些研究表明，MPH可用于处理水中的有机污染物。在此，我们提出一个新的观点，即MPH在解决重金属污染方面可能也具有巨大潜力。废水中的重金属有可能通过微生物矿化作用被利用来合成用于MPH的光催化剂。MPH中的光催化剂产生的光致电子可以转移到微生物细胞中，促进细胞内的酶促还原反应，从而使铬和硒等重金属离子被还原并解毒。此外，砷和锑等重金属离子可以用作牺牲电子供体，以维持MPH的持续运行，在此过程中这些金属离子同时被氧化并解毒。本文解释了MPH在处理重金属污染废水方面的优异潜力，并提出了基于MPH的解决方案，同时进行了实验验证。该解决方案可以实现不同金属离子之间的电子转移，从而同时修复废水中的多种重金属离子。这一发现可能为未来处理多种重金属污染废水带来新的希望。
