Study on the environmental durability of heavy metal contaminated soil remediated by enzyme induced carbonate precipitation

Authors

Han-liang BIAN, School of Civil Engineering and Architecture, Henan University, Kaifeng, Henan 475004, China; Kaifeng Technology Research Center of Engineering on Soil Modification and Restoration, Henan University, Kaifeng, Henan 475004, ChinaFollow
Pei-rui JI, School of Civil Engineering and Architecture, Henan University, Kaifeng, Henan 475004, China
Jun-ling WANG, Scivic Engineering Corporation, Luoyang, Henan 471003, China
Xu-gang ZHANG, The Second Construction Limited Company of China Construction Eighth Engineering Division, Jinan, Shandong 250014, China
Xiang-chun XU, School of Civil Engineering and Architecture, Henan University, Kaifeng, Henan 475004, China; Kaifeng Technology Research Center of Engineering on Soil Modification and Restoration, Henan University, Kaifeng, Henan 475004, ChinaFollow

Abstract

To explore the environmental durability of heavy metal contaminated soil remediated by enzyme induced carbonate precipitation (EICP) technology, acid soaking, freeze-thaw tests, and rainfall tests were carried out on the zinc and lead contaminated soil after EICP remediation, respectively. The durability and influence of the zinc and lead contaminated soil remediated by EICP technique under different environmental conditions and the corresponding influence regularity were discussed in this paper. The results showed that under different concentrations and types of acid solutions, the leaching amount of heavy metal ions in exchangeable and carbonate bound forms in the zinc and lead contaminated soil after EICP remediation decreased with pH value, with the content of ions in carbonate bound forms decreasing and the content of ions in exchangeable forms gradually increasing. It was also found that the stability in sulfuric acid solution was greater than that in nitric acid solution. As the number of freeze-thaw cycles increased, the leaching amount of exchangeable ions in the zinc and lead contaminated soil remediated by EICP technique increased, while the content of ions in the carbonate bound form reduced. Under the condition of heavy rain, Zn2+ and Pb2+ were mainly released within the first 20 minutes and migrated from top to bottom. All the results demonstrate that the heavy metal contaminated soil remediated by EICP technology has a good durability under acid soaking, freeze-thaw cycles, and heavy rain.

Recommended Citation

BIAN, Han-liang; JI, Pei-rui; WANG, Jun-ling; ZHANG, Xu-gang; and XU, Xiang-chun (2023) "Study on the environmental durability of heavy metal contaminated soil remediated by enzyme induced carbonate precipitation," Rock and Soil Mechanics: Vol. 44: Iss. 10, Article 1.
DOI: 10.16285/j.rsm.2023.5992
Available at: https://rocksoilmech.researchcommons.org/journal/vol44/iss10/1