Water-Holding Properties of Clinoptilolite/Sodium Polyacrylate-Modified Compacted Clay Cover of Tailing Pond

Xin-Po Sun; Ze-Hao Ding; Yu-Zhang Bi; Xin-Yi Wang

doi:10.3390/ijerph192315554

Water-Holding Properties of Clinoptilolite/Sodium Polyacrylate-Modified Compacted Clay Cover of Tailing Pond

Int J Environ Res Public Health. 2022 Nov 23;19(23):15554. doi: 10.3390/ijerph192315554.

Authors

Xin-Po Sun¹, Ze-Hao Ding¹, Yu-Zhang Bi², Xin-Yi Wang³

Affiliations

¹ College of Civil Engineering, Sichuan University of Science & Engineering, Zigong 643000, China.
² Institute of Geotechnical Engineering, Southeast University, Nanjing 210096, China.
³ School of Design, Hong Kong Polytechnic University, Hong Kong 999077, China.

Abstract

Clinoptilolite and sodium polyacrylate (Na-PAA) were used as water-retaining agents to improve the water-holding capacity of compacted clay cover (CCC). The optimum moisture content and Atterberg limits of the CCC modified by clinoptilolite and Na-PAA were studied. The soil-water characteristic curve (SWCC) of the CCC modified by clinoptilolite and Na-PAA was studied. The mesostructure of the CCC was analyzed by polarized light microscopy. The test results show that: (1) the optimum moisture content and liquid limit of the CCC modified by clinoptilolite and Na-PAA increased, while the maximum dry density decreased; (2) the SWCC of the CCC modified by clinoptilolite and Na-PAA shifts to the upper right, and the volume moisture content of modified CCC is higher than that of unmodified CCC under the same matrix suction; (3) compared with the unmodified CCC, the air-entry value (AEV) of the clinoptilolite-modified CCC increased by 65.18% at most, and the AEV of the further modified CCC with Na-PAA in-creased by about two times; and (4) the flocculation structure and porosity of modified CCC decreased, and the porosity was distributed uniformly.

Keywords: clinoptilolite; sodium polyacrylate (Na-PAA); soil–water characteristic curve; tailing pond; water-holding capacity.

Publication types

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

MeSH terms

Clay
Ions
Sodium
Soil
Water*
Zeolites* / chemistry

Substances

carbopol 940
Water
Clay
clinoptilolite
Zeolites
Soil
Sodium
Ions

Grants and funding

This study was financially supported by the Key projects of science and Technology Department of Sichuan Province (2020YJ0360). Sichuan Education and teaching reform project (JG2021-1070), and The opening project of Sichuan Province University Key Laboratory (SC_FQWLY-2020-Z-02), Scientific Research Foundation of Graduate School of Southeast University (Grant No.YBJJ 1844), and Postgraduate Research and Practice Innovation Program of Jiangsu Province (Grant No. KYCX17_0130).