The use of local materials to remove heavy metals for household-scale drinking water treatment: A review

Providing access to safe and clean drinking water requires that materials and technologies for treating polluted water are affordable, operated without much difficulty and produced locally. To this effect, agricultural wastes, natural soils and materials as well as treatment technologies that are easily put together were investigated. Experimental results indicate that the use of these locally available materials and technologies are viable in removing heavy metals such as lead, zinc, arsenic, copper, cadmium and chromium. The use of banana peels, cassava peels, coconut shells and husks and rice husks were found to have high removal efficiencies in relation to the heavy metals being removed. Natural soils such clay and zeolites were found to be potent in removing heavy metals such as chromium, arsenic and cadmium with significant removal efficiencies. Treatment technologies such as modified ceramic water filters with cerium oxide and iron oxide observed significant heavy metal removal. This literature review of experimental results shows that environmental factors such as pH, metal ion concentration, and adsorbent concentration influenced removal of heavy metals from solutions and this could be a challenge in achieving efficient removal of heavy metals. It is therefore important to improve upon technologies and materials for the efficient removal of heavy metals.