Feasibility of Singapore IBA waste for land reclamation

Abstract

Bottom ash from municipal solid waste incineration plants represents an untapped resource in many countries. This paper examines both heavy metal leaching and undrained shear strength of using Singapore’s local incineration bottom ash (IBA) as land reclamation material. The IBA was mixed in various proportions (0–30%) with Singapore marine clay (MC) and an additive binder. The resultant materials were named MC-IBA matrices and were tested for shear strength and leached with seawater and ethanoic acid in separate tests to simulate possible scenarios in the environment. Shear strength tests showed that higher amounts of IBA resulted in higher strength values. Seawater percolation tests showed that heavy metals were not exchanged and mobile, except for cadmium, and only when the material contained a high proportion of IBA of at least 30%. Toxicity characteristic leaching procedure tests showed that the matrices could be considered non-hazardous material.