Abstract

There has been an increased concern over the level of heavy metals in the environment because of the serious environmental hazards these metals pose. Mercury is one of these heavy metals present in the environment. Mercury undergoes complex chemical and physical transformation once released to the air, land or rivers. The main sources of mercury are the natural and anthropogenic sources. Mercury may be emitted to the atmosphere as a gas or particulate matter, which may return to the earth’s surface either dry by gravitational settling or wet by precipitation. While it circulates and changes its form, it becomes persistent. It tends to accumulate in sediments of water bodies. Mercury constitutes a considerable hazard to vertebrates including man and it is bioaccumulating in biota. The detoxification of mercury from aqueous solutions has been achieved by conventional methods such as precipitation, coagulation, reverse osmosis, ion exchange and adsorption using activated carbon. Recent advances in mercury remediation include the use of agricultural by-products and microorganisms as adsorbent. The application of biosorbents has proved to be a very good process for mercury remediation from aqueous solutions. This paper reviews the toxicity of mercury and its remediation processes.

Key words: Mercury, detoxification, pollution, environment, heavy metals.