Reviews on the Applicability of Construction and Demolition Waste as Low-Cost Adsorbents to Remove-Heavy Metals in Wastewater

Removal of heavy metals from wastewater is of special concern due to the persistence of heavymetals in the environment. The industrial discharge of heavy metals adversely affects soil and water resources,aquatic organisms, and ecosystem integrity. In addition, high concentrations of heavy metals are detected in solidwaste landfill leachate in many developing countries due to non-segregated waste dumping. At present, variouskinds of adsorbents such as activated carbon, biomass resources, geomaterials, and industrial waste products areused to treat heavy metal-contaminated water. However, the use of construction and demolition waste (CDW)and its recycled materials to treat heavy metal-contaminated water has not been fully examined. Because thegeneration of CDW is increasing due to rapid urbanization and a high demand for construction, the wise use ofCDW and its recycled materials is necessary. This paper reviews journal articles published from 2004 to 2016that studied the applicability of low-cost CDW adsorbents to remove heavy metals from wastewater. In particu-lar, it summarizes results on using CDW and recycled materials such as cement, concrete, and brick compared tothose from various other adsorbents such as biosorbents, geomaterials, and their industrial products. The poten-tial applicability of CDW and its recycled materials as heavy-metal adsorbents was examined based on a com-parison table listing material properties, test conditions, and measured adsorption properties.