Microorganism and Agricultural Based Biosorbents Towards Removal of Cadmium from Waste-Water: An Overview.

Abstract

Non-degradable and persistent nature of Cadmium (Cd) poses high toxicity to human, plants and animals. Several industrial processes generated wastes are the main anthropogenic pathway through which Cd enters into the environment. Although, World Health Organization (WHO) has set the limit of Cd in drinking water is 0.005 mg L-1, the industrial activities release much higher concentrations of metal ions to the water stream than the prescribed limits, which leads to the increasing health hazards and environmental pollution. To address this issue, one of the major applicable solutions is the treatment or purification of contaminated water and effluents. The implantation of wastewater treatment systems aims to minimize environmental impacts, but ultimately generates waste materials, such as sewage sludge, which must be properly recycled. In this review, we focus on the research efforts being made towards the removal of Cd (II) from waste waters using biological means with a special emphasis on the microorganism and agricultural based biosorbents. Mechanistic pathway towards removal of Cd (II) ions from the wastewater, efficiency of the adsorbents and the factors affecting the process have been studied with specific examples. Also the recent patents related to this area have been taken into considerations to understand applicability of microorganism and agricultural based biosorbents. This overview presents various scientific reports towards low-cost microorganism and agricultural based biosorbents for efficient removal of Cd (II) by producing less toxic waste and the future perspective of the process.