Assessing Chromium Contamination in Red Soil: Monitoring the Migration of Fractions and the Change of Related Microorganisms

Abstract

The improper stacking of chromium (Cr) slag poses a great threat to the environment and human health. The toxicity of Cr in soil is not only related to its total amount, but also to its fractions. A simulated experiment was conducted in laboratory to assess the environmental risk of Cr fractions migration and distribution in red soil. The results showed the content of acid-soluble and reducible Cr significantly decreased (P < 0.05) in top layer but increased in middle and substratum layers over time. This indicated that acid-soluble and reducible Cr migrated downward with time and the relative mobility of acid-soluble Cr (0.038 mg/kg·d·m) was higher than that of reducible Cr (0.028 mg/kg·d·m). Furthermore, correlation analysis between microbial community and chromium fraction showed the relative abundance of Lysobacter, Flavihumibacter, Flavisolbacter, and Altererythrobacter was significantly (P < 0.05) correlated with acid-soluble and reducible fractions. Thus, these microorganisms might be evaluators to assess the migration of acid-soluble and reducible fractions in red soil. In summary, this study provided a new comprehension on remediation of Cr-contaminated soil by monitoring the migration of acid-soluble and reducible fractions and the changes of related microbial groups.

Insight into functional microorganisms in wet–dry conversion to alleviate the toxicity of chromium fractions in red soil

“…The results indicated that the contents of the four fractions in Cr slag diminished during the 0–90-day LP. In our previous study, F1 and F2 migrated downward in the soil profile ( Zhang et al, 2020c ). It was suggested that the decreases in F3 and F4 may have been due to the shifts of F3 and F4 to the fractions that migrated easily.…”

“…All PMMA columns were wrapped with tinfoil to avoid the effects of sunlight. In our previous study, spraying 205 ml of water per week saturated the soil layer at 90 days, and the acid-soluble and reducible Cr solutions migrated downward ( Zhang et al, 2020c ). To mimic the leaching process (LP), the CK and TG groups were sprinkled with water weekly using a spray kettle and sampled on days 0 and 90.…”

“…The distribution and chemical association of potentially toxic elements in sediment and soil greatly affect their bioavailability and mobility ( Pérez et al, 2008 ; Chen et al, 2017b ; Jiang et al, 2020 ). Furthermore, studies have shown that the potential hazards of Cr under field conditions are dominated by its mobility and ecotoxicological properties in the solid–liquid phase ( Shi et al, 2009 ; Zhang et al, 2020c ). That is, it is not sufficient to focus only on the total amounts of potentially toxic elements; their mobility and bioavailability should also be examined.…”

Identification of a Phosphorus-Solubilizing Tsukamurella Tyrosinosolvens Strain and its Effect on the Bacterial Diversity of the Rhizosphere Soil of Peanuts Growth-Promoting

“…had nitrogen fixation ability (Msaddak et al 2017). There are few research reports on Flavihumibacter sp., but it has been reported that most of the strains of this genus were isolated from forest soil, sediment of a shallow stream, and had bioremediation capabilities (Lee et al 2014;Kim et al 2014;Zhang et al 2020). In addition, as a rare actinomycete, the family Tsukamurellaceae, genus Tsukamurella, and Tsukamurella tyrosinosolvens was detected only in the rhizosphere soil of the inoculation group, while the control group did not have such microorganisms, indirectly indicated that the P9 strain was able to colonize plant rhizosphere soil, which has been confirmed by our subsequent experiments (unpublished data).…”

Influence of Heavy Metals on the Process of Anaerobic Fermentation of Biomass by the Consortia of Anaerobic Microorganisms

“…Cr(III) -важливий мікроелемент, необхідний для метаболізму глюкози, ліпідів й амінокислот, однак у високих концентраціях чинить негативний вплив на клітинні структури. Також іони хрому відіграють регуляторну роль у процесах реплікації та транскрипції в мікроорганізмах [29][30][31][32][33]. При додаванні до середовища хром-метіоніну (ІІІ) в концентрації 0,5-1,5 ммоль/л спостерігається активація анаболічних процесів, целюлозо-й амілолітичної активності, росту клітин мікроорганізмів, унаслідок чого збільшується їх маса [34].…”