Premium
Effects of seepage velocity and concentration on chromium(VI) removal in abiotic and biotic iron columns
Author(s) -
Yin Weizhao,
Fang Zhanqiang,
Huang Jingling,
Li Ping,
Zhong Jiawei,
Chiang Penchi,
Wu Jinhua
Publication year - 2020
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.1002/jeq2.20018
Subject(s) - chromium , chemistry , adsorption , environmental chemistry , abiotic component , water column , permeable reactive barrier , environmental remediation , contamination , geology , ecology , biology , paleontology , oceanography , organic chemistry
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 −1 and from 5 to 40 mg L −1 , respectively. When the Cr(VI) loading varied in a range of 0 to 10 mg L −1 h −1 , 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 0 –based permeable reactive barriers.