Research on soil improvement for waste rock piles remediation

We used the sludge in domestic sewage treatment plant to improve the soil's properties. Firstly, we analyzed the exploitability of soil, and then added the sludge to the soil. The sludge dose is 0, 10%, 20%, 30% and 40% and 20% sludge dosage is the optimized value for the planting ryegrass.