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

• Published in: International journal of environmental research and public health 2022-11, Vol.19 (23), p.15554
• Main Authors: Sun, Xin-Po, Ding, Ze-Hao, Bi, Yu-Zhang, Wang, Xin-Yi
• Format: Article
• Language: English
• Subjects: Acrylic resins; Atterberg limits; Clay; Cracks; Density; Dry density; Flocculation; Hydraulics; Ions; Light microscopy; Liquid limits; Mining; Moisture content; Optical microscopy; Particle size; Polarized light; Polyacrylate; Polymers; Porosity; Sodium; Soil; Soil moisture; Soil porosity; Soil water; Water; Water content; Zeolites; Zeolites - chemistry
• ISSN: 1660-4601; 1661-7827; 1660-4601
• DOI: 10.3390/ijerph192315554

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.