Feasibility of re-using soil-like material obtained from mining of old MSW dumps as an earth-fill and as compost

The present study examines the feasibility of using the soil-like material (SLM), less than 4.75 mm size, recovered by the mining of old waste from four municipal solid waste dumps of India as an earth-fill for embankments, low-lying areas, deep pits and as compost for horticulture, agricultural applications. This material constitutes 60-70% of the total excavated waste. The contamination levels of SLM for re-use as earth-fills were analyzed on the basis of heavy metals, organic content, soluble salts, and release of dark-colored leachate. The reuse feasibility of SLM as compost was assessed on the basis of nutrients levels (total organic carbon, nitrogen, phosphorous, and potassium), heavy metals, and physicochemical characteristics. All the obtained results were compared with the values reported in the literature, national and international regulatory guidelines as well as with the background soils. The presence of high levels of organic matter, heavy metals, and soluble salts indicate that the SLM requires treatment before off-site re-use or that specific design measures are must before placing it as earth-fill in embankments, low-lying areas, and deep pits. The study also reveals that the re-use of mined SLM as compost should be restricted to non-agricultural applications due to excess heavy metals after supplementing the total organic carbon. (C) 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

Automated summary

This study examines the feasibility of recycled soil-like material for earth-fill and compost, highlighting the need for treatment or specific design measures before reuse.