Long term leaching behavior of arsenic from cemented paste backfill made of construction and demolition waste: Experimental and numerical simulation studies

Hengfeng Liu; Jixiong Zhang; Baiyi Li; Nan Zhou; Danqi Li; Luobin Zhang; Xin Xiao

doi:10.1016/j.jhazmat.2021.125813

Long term leaching behavior of arsenic from cemented paste backfill made of construction and demolition waste: Experimental and numerical simulation studies

J Hazard Mater. 2021 Aug 15:416:125813. doi: 10.1016/j.jhazmat.2021.125813. Epub 2021 Apr 7.

Authors

Hengfeng Liu¹, Jixiong Zhang², Baiyi Li³, Nan Zhou⁴, Danqi Li⁵, Luobin Zhang⁴, Xin Xiao⁶

Affiliations

¹ State Key Laboratory of Coal Resources and Safe Mining, School of Mines, China University of Mining and Technology, Xuzhou 221116, China; Key Laboratory of Coal Resources and Mineral Resources, Jiangsu Design Institute of Geology for Mineral Resources, China National Administration of Coal Geology, Xuzhou 221116, China.
² State Key Laboratory of Coal Resources and Safe Mining, School of Mines, China University of Mining and Technology, Xuzhou 221116, China. Electronic address: zjxiong@163.com.
³ State key laboratory for geomechanics & deep underground engineering, China University of Mining and Technology, Xuzhou 221116, China.
⁴ State Key Laboratory of Coal Resources and Safe Mining, School of Mines, China University of Mining and Technology, Xuzhou 221116, China.
⁵ WA School of Mines: Minerals, Energy and Chemical Engineering, Curtin University, Kalgoorlie, WA 6430, Australia. Electronic address: danqi.li@curtin.edu.au.
⁶ School of Environment Science and Spatial Informatics, China University of Mining and Technology, Xuzhou 221116, China.

PMID: 33862486
DOI: 10.1016/j.jhazmat.2021.125813

Abstract

The arsenic long-term leaching behavior of the cemented paste backfill obtained from the construction and demolition waste (CPB-CDW) is captured, which can be utilized in the potential engineering application. Laboratory studies were conducted on samples obtained from a mining site and the test results were imported into a numerical simulation model. It was found that the Elovich equation can describe well the As leaching behavior. Initially, the As concentrations decreased in the roadway in the mine and then increased along the roadway and attained a maximum concentration (8.149 × 10^-3 mg/L) at the lower segment. When the groundwater was in the static mode, the As concentration increased dramatically followed by a gradual increase. Eventually, the concentration decreased gradually. For the dynamic condition, the As tended to move in a cluster form and the associated leaching and mass transfer process of As in the CPB-CDW were similar to those observed when the groundwater was in a static condition. However, the difference in the distribution of the amount of As in the leachate fluctuated continuously and the overall trend was to approach a steady state. As such, the time frame of such a mass transfer in the mobilized water is reduced significantly.

Keywords: Backfilling mining; Construction and demolition waste; Leaching behavior; Numerical simulation; Toxicity migration.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Arsenic* / analysis
Construction Materials
Mining

Substances

Arsenic