School of Environment and Energy, South China Univ. of Technology, Guangzhou, 510006, PR China.
School of Environment, Jinan Univ., Guangzhou, 510632, PR China.
J Environ Qual. 2020 May;49(3):654-662. doi: 10.1002/jeq2.20018. Epub 2020 Mar 18.
Continuous-flow iron and bio-iron columns were used to evaluate the effects of seepage velocity and concentration on Cr(VI) removal from groundwater. Solid-phase analysis showed that microorganisms accelerated iron corrosion by excreting extracellular polymeric substances and generated highly reactive minerals containing Fe(II), which gave the bio-iron column a longer life span and enhanced capacity for Cr(VI) removal via enhanced adsorption and reduction by reactive minerals. The bio-iron column showed much higher Cr(VI) removal capacity than the iron column with increasing Cr(VI) loading, which was obtained by increasing the seepage velocity or influent Cr(VI) concentration from 95 to 1138 m yr and from 5 to 40 mg L , respectively. When the Cr(VI) loading varied in a range of 0 to 10 mg L h , the bio-iron column had a 60% longer longevity and one- to sixfold higher Cr(VI) elimination capacity than the iron column. This result indicated that, under fluctuating hydraulic conditions [e.g., seepage velocity and Cr(VI) concentration], the presence of microorganisms can significantly boost Cr(VI) removal using Fe -based permeable reactive barriers.
连续流铁和生物铁柱被用于评估渗流速度和浓度对地下水六价铬去除的影响。固相分析表明，微生物通过分泌胞外聚合物加速铁的腐蚀，并生成含有 Fe(II)的高反应性矿物，这使得生物铁柱具有更长的寿命，并通过增强反应性矿物的吸附和还原作用增强了对 Cr(VI)的去除能力。随着 Cr(VI)负荷的增加，生物铁柱的 Cr(VI)去除能力比铁柱高得多，这是通过将渗流速度或进水 Cr(VI)浓度从 95 增加到 1138 m yr 和从 5 增加到 40 mg L 来实现的。当 Cr(VI)负荷在 0 到 10 mg L h 的范围内变化时，生物铁柱的寿命比铁柱长 60%，Cr(VI)去除能力高 1 到 6 倍。这一结果表明，在波动的水力条件下（例如渗流速度和 Cr(VI)浓度），微生物的存在可以显著提高基于铁的渗透性反应屏障对 Cr(VI)的去除效果。
