Strength and Leaching Characteristics of Magnesium Phosphate Cement-Solidified Zinc- Contaminated Soil under the Effect of Acid Rain. Issue 2 (17th February 2018)

• Record Type: Journal Article
• Authors: Xu, Sifa; Wu, Xuehui; Cai, Yuanqiang; Ding, Yaokun; Wang, Zhe
• Is Part Of: Soil & sediment contamination. Volume 27:Issue 2(2018)
• Page Start: 161
• Page End: 174
• Publication Date: 2018-02-17
• Subjects: Acid rain -- leaching characteristics -- magnesium phosphate cement -- solidification/stabilization -- unconfined compressive strength; Soil pollution -- Periodicals; Soil protection -- Periodicals; 628.5505
• DOI: 10.1080/15320383.2018.1438364
• Languages: English
• ISSNs: 1532-0383

Abstract

ABSTRACT: Long-term static leaching experiments were conducted to investigate characteristics of magnesium phosphate cement (MPC) solidified/stabilized Zn-contaminated soil under impact of acid rain. Effects of initial pH values of acid rain, binder agent types and compositions, as well as curing age on strength and leaching characteristics of the sample were analyzed. Standard sand was used as raw material, with the content of cement at 15%. Our study used two types of MPC with MgO/KH2 PO4 (M/P) ratio of 3:1 and 6:1 (respectively referred to as M3 and M6), and also ordinary Portland cement with content at 15% (referred to as C15) as test control. Experimental results show that acid rain with pH = 2 has the greatest weakening effect on unconfined compressive strength (qu ) of the sample, while with pH = 4 and 7 such weakening effects on qu are similar. Research findings also indicate that M6 is the most effective in immobilizing Zn-spiked soils, M3 is next and C15 is the least. The effect of Zn 2+ on hydration of MPC is much lower than that of C15. Precuring method can improve qu of the MPC-solidified samples and its resistance to acid rain. Compared with non-renewal, replacing acid rain leachant at designated intervals decreases qu of the sample.