Improvement and Remediation of Degraded Soil Based on Solid Waste

Abstract

Aiming at the problem that coal gasification coarse slag is seldom used in soil improvement at present, this study takes the waste dump of Hongshaquan No.1 open-pit mine in Zhundong, Xinjiang, as the research object, uses the local coal gasification coarse slag to prepare coal-based soil improver to improve the soil in the study area, and compares it with the improvement effect based on fly ash and domestic sludge to explore the soil improvement effect of different solid wastes. The improvement experiment results show that, in terms of soil particle size, the addition of fly ash and domestic sludge can increase the soil clay content and reduce the sand content, but the effect of coal gasification coarse slag on soil particle size composition is not obvious. In terms of soil nutrients, fly ash will reduce the content of soil organic matter, available potassium and alkali hydrolyzable nitrogen, but increase the content of available phosphorus. Coal gasification coarse residue will increase the content of soil organic matter and available phosphorus, but it has little effect on the content of available potassium and alkali hydrolyzable nitrogen. Domestic sludge will improve the contents of soil organic matter, available potassium, alkali hydrolyzable nitrogen and available phosphorus. In terms of soil pH, fly ash and coal gasification coarse slag will increase soil alkalinity, and domestic sludge will reduce soil alkalinity. The results of the pot experiment in the field showed that the coal gasification coarse slag had the best improvement effect, followed by domestic sludge and finally fly ash. By clarifying the effect of improved materials, this study can better use coal-based solid waste resources in the field of ecological restoration of degraded soil, so as to provide a scientific basis for the ecological reconstruction and pollution restoration of local arid ecologically fragile saline alkali land.