Remediation of chromium-contaminated soil in semi-arid areas by combined chemical reduction and stabilization

ABSTRACT

The indoor simulation remediation of chromium-contaminated soil in semi-arid areas with chemical reduction-stabilization method was conducted to study the effects of remediation agent types and dosage, water (mL)-soil (g) ratio and remediation time on reduction and stabilization efficiency of the chromium-contaminated soil. The results showed that FeSO4 was the most effective reduction agent for reduction of Cr(VI) in soil. The optimally combined chemical reduction-stabilization remediation conditions were 2.5 times theoretical reaction dosage FeSO4 and 8% of modified corn stover biochar (KBC), 50% of water-soil ratio, and 7 days remediation time. The total Cr and Cr(VI) leaching concentrations and Cr(VI) content in soil were reduced from 65.65 mg L-1, 61.98 mg L-1 and 1000.00 mg kg-1 without treatment to 0.114 mg L-1, 0.125 mg L-1 and 18.909 mg kg-1 after treatment, respectively. They were according with comprehensive wastewater discharge standards and construction land soil contamination risk control standards, respectively.

Graphical abstract

KEYWORDS:

• Semi-arid area
• chromium contaminated soil
• chemical reduction
• stabilization
• soil remediation

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research was supported by the Fundamental Research Funds for the Central Universities (Grant number: 31920190014), the National Natural Science Foundation of China (Grant number: 21966028) and 2021 Key Talent Project of Gansu, 2021 Science and Technology Project of Gansu (Grant number: 21YF5GA062).