Removal of Cd(II) from water sources using low-cost materials, modified low-cost adsorbents: A review

In emerging countries, Cd(II) contamination is becoming a growing issue. Toxic to living things, cadmium(II) is an extremely dangerous metal. It is classified as a carcinogen by the International Agency for Research on Cancer (IARC) by the US Environmental Protection Agency (EPA), and strict limitations have been set for its presence in industrial effluent (which is released into cadmium-containing water bodies) and drinking water. The need for a cost-effective and efficient method to remove cadmium from water is urgent in underdeveloped countries. Waterways in developing nations have been increasingly contaminated with Cd(II) due to poor water and wastewater treatment and growing industrial activities. Water purification methods including membrane filtration, ion exchange, electrocoagulation, nanotechnology and activated carbon are ineffective in these countries due to the economic issues. Thus, substantial study has been done on inexpensive adsorbents to test their efficiency to remove cadmium from the environment. We focused on cost-effective adsorbents that can be used in the undeveloped countries, this review paper examines the current status of Cd(II) removal research. Two major kinds of adsorbents are examined in this review: different kinds of low-cost materials, and modified low-cost materials. This study also focused on the effects of various water-quality conditions on Cd(II) and these adsorbents, as well as their application in the removal of Cd(II).