Sustainable Resource Utilization of Pisha Sandstone in China: A Review from Erosion Control to Preparation of Low-Carbon Geopolymer Cementitious Materials and Amelioration of Degraded Soils

Pisha sandstone (PS) is a weakly cemented soft rock widely distributed in the middle reaches of the Yellow River, China. PS disintegrates rapidly upon contact with water and has poor erosion resistance, making it a major source of coarse sediment in the Yellow River. However, PS is rich in aluminosilicate minerals and clay fractions, offering great potential as a sustainable precursor for geopolymer cementitious materials and as an amendment for degraded soils. The sustainable resource utilization of PS provides a new pathway for coordinated ecological and economic development in the PS areas. This paper first reviews the mineralogical and chemical characteristics of PS, clarifying that low diagenetic degree and high montmorillonite content cause poor erosion resistance, and that compound erosion from freeze–thaw, water, wind, and gravity erosion creates a superimposed amplification effect, which is the primary driver of severe soil erosion. Subsequently, three major control measures for soil erosion in the PS areas are summarized, namely biological measures using sea-buckthorn (Hippophae rhamnoides), chemical solidification, and microbially induced calcium carbonate precipitation (MICP), with analyses of their mechanisms, efficiency, and limitations. Furthermore, the research progress on the sustainable resource utilization of PS in the preparation of geopolymer cementitious materials and the amelioration of degraded soils is elaborated. Finally, future research directions are discussed to support the control of soil erosion and the green, sustainable resource utilization of PS.