ROASTED CHINA CLAY AS A POTENTIAL ADSORBENT FOR THE REMOVAL OF HEAVY METALS FROM WATER AND WASTE WATER

Abstract

Environmental contamination of water due to toxic heavy metal ions is becoming a serious threat to the
environment and human health in particular due to their detrimental accumulation in living tissues, soil and water
bodies. Utilization of one waste material to control pollution caused by another is of high significance in the remediation
of environmental problems. Clays are abundantly available natural material which has remarkable ability to adsorb
heavy metals either in their natural form or after treating with some suitable chemicals. Many types of clays have been
employed in removing heavy metals from industrial effluent. Researchers have studied the extent of uptake of different
metals with the tested clays under different conditions such as pH, time of clay residence in solution with different
concentration of metal and clay’s mass. Langmuir, Freundlich adsorption isotherms are commonly used for fitting
experimental data. Conventional technologies for the removal of heavy metals from wastewater are proving expensive
due to non-regenerable materials used and high costs. Adsorption is an emerging technique offering the use of
economical alternative materials as adsorbents for the removal of heavy metals from waste water. Roasted china clay is
a waste of ceramic industry which is available free of cost in bulk. It has great potential to remove heavy metals ions
from wastewaters. This paper is a review for the use of various clays to exhibit different affinities towards different
metals and hence its importance to be employed as an effective adsorbent. For commercial use of roasted china clay to
remove metal ions from wastewater, emphasis should be given to the selection of metal to get high sorption capacity.
Adequate understanding of sorption mechanism and development of low cost methods facilitate better prediction of metal
sorption.