Graphical abstract
Industrial wastes, such as, fly ash, blast furnace slag and sludge, black liquor lignin, red mud, and waste slurry, etc. are currently being investigated as potential adsorbents for the removal of the heavy metals from the wastewater. It was found that the modified industrial wastes showed higher adsorption capacity. The application of low-cost adsorbents obtained from the industrial wastes as a replacement for costly conventional methods of removing heavy metal ions from wastewater has been reviewed. From the review, it is evident that certain industrial waste materials have demonstrated high removal capacities for the heavy metals laden with wastewater. The figure shows the adsorption capacities of Zn(II) on various industrial wastes adsorbents.