Low-cost biomass as adsorbents for the removal of heavy metal from industrial wastewater used for crop irrigation in developing countries

Abstract

Freshwater scarcity has prompted farmers in developing countries to rely on wastewater for agriculture. However, the concentrations of heavy metals in the wastewaters are found to be above the WHO/FAO recommended thresholds. This inherently presents concern particularly as it relates human health. Although, several conventional wastewater treatment technologies exist; their applications are limited by high procurement, operation and maintenance costs. Currently, studies on biomass wastes as low cost adsorbents are gaining momentum. In this study, coco-peat was considered for heavy metals removal. In this context, batch experiments were carried out in triplicates at 3 different contact times and pH. After 2hr of contact time at pH9, the coco-peat was proven to have Cr removal efficiency of 91.6% against 73.2% using an activated bone char; and 95.0% for Pb(II) against 91.2% for the bone char. This suggests that the use of coco-peat can provide cost effective means for metal removal from industrial wastewaters.