Characterization of Red Mud-based Curing Agent for Curing High Concentration Copper Contaminated Soil

Hao Liu; Zhongyu Yu; Zeju Wu; Xin Xu

doi:10.54097/v7dsvb78

Authors

Hao Liu
Zhongyu Yu
Zeju Wu
Xin Xu

DOI:

https://doi.org/10.54097/v7dsvb78

Keywords:

Red Mud, Curing, Heavy Metals, Unconfined Compressive Strength, Toxic Leaching Concentration, Resistivity, Microanalysis

Abstract

In order to investigate the characteristics of RCP (red mud: calcium carbide slag: cement = 3:1:1) curing agent for curing soil with high concentration of copper contamination, this paper carried out the unconfined compressive strength test, toxicity leaching test, electrical resistivity test, and scanning electron microscopy test on RCP specimens with different age of maintenance, different curing agent dosages and different initial heavy metal contamination concentrations to investigate and analyze the Unconfined compressive strength characteristics, heavy metal ion leaching concentration characteristics and resistivity characteristics of RCP cured soil under different variables.It was found that the unconfined compressive strength and resistivity of RCP cured soil increased with the increase of maintenance age and curing agent dosing, while the strength and resistivity of cured soil decreased when the initial heavy metal contamination concentration increased. The heavy metal ion leaching concentration of RCP cured soil decreased with the increase of maintenance age and curing agent dosage, while the heavy metal ion solidification rate of cured soil decreased when the initial heavy metal pollution concentration increased.By observing and analyzing the swept electron microscope images of RCP specimens maintained for 28 days, the presence of Calcovanite, hydrated calcium silicate and hydrated calcium silica-aluminate can be observed, and these hydration reaction products enhance the strength of the cured soil, as well as displace and adsorb heavy metal ions in the contaminated soil, which have a better curing effect on the heavy metal ions.

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References

Ministry of Environmental Protection of the People's Republic of China, Ministry of Land and Resources of the People's Republic of China. Report on the national general survey of soil contamination [EB/OL], (2014) [2022]. http://www. gov. cn/ xinwen/ 2014-04/17/content_2661765. Htm.

WANG Ting,CHANG Gaofeng.Present situation and remediation technology research progress for heavy metal contaminated soil[J]. Inner Mongolia Environmental Sciences, 2017, 29(1):33–36.

Yangyang Wang,Fangfang Li,Jian Song,Ruiyang Xiao,Lin Luo,Zhihui Yang, Liyuan Chai.Stabilization of Cd-,Pb-,Cu-and Zn-contaminated calcareous agricultural soil using red mud: A field experiment[J].Environmental Geochemistry and Health,2018,40(5):2143-2153.

LIU Zhaobing,JI Xionghui,WANG Guoxiang,et al. Effects of red–mud on rice growth and cadmium uptake in cadmium polluted soil [J]. Journal of Agri–Environment Science, 2010, 29(4):692–697.

KILINCKALE F,AYHAN S,APAK R. Solidification/ stabilization of heavy metal–loaded red muds and fly ashes[J]. Journal of Chemical Technology and Biotechnology, 1997, 69 (2): 240–246.

SHIN W,KIM Y K. Stabilization of heavy metal contaminated marine sediments with red mud and apatite composite[J]. Journal of Soils and Sediments,2016,16(2):726–735.

CHEN Yonggui, ZHU Shenyi, TAN Banghong, et al. Leaching characteristic of solidification/stabilization for Cu2+ contaminated soils with carbide slag and metakaolin[J]. Journal of Tongji University (Natural Science), 2018, 46(2): 182-187.