Eco-friendly beads developed by IIT (BHU) can remove heavy metals from wastewaters
Varanasi: While the pollution of Ganga and other rivers or water bodies has been a matter of great concern, the School of Bio Chemical Engineering, IIT (BHU) has come up with an eco-friendly solution particularly the removal of heavy metals from the wastewaters.
Dr. Vishal Mishra of the School of Bio Chemical Engineering, IIT (BHU) has developed a low-cost bead to successfully remove the hazardous heavy metals from contaminated water. He claims that the composite bead made of saw dust, bentonite clay and natural soil is able to remove heavy metals with an efficiency of 99.997% within 30 minutes.
“Heavy metals are placed in the fourth period of the periodic table like Cu (Copper), Ni (Nickel) and Zn (Zinc). Source of toxic pollutants may be natural (volcanoes, earthquakes) or anthropogenic (industrial sources),” said Mishra adding that the removal of these heavy metals becomes essential because of the release of carcinogenic substances in the environment that needs not to be discharged directly into the waterbodies. Heavy metals are a source of concern as these are non-biodegradable, toxic and also persistent in the environment. Being highly soluble in the water the heavy metals are taken up by the fishes and the vegetables, and get accumulated in the body of humans and animals, as they consume it.
He said that it is an eco-friendly and inexpensive method of removing heavy metal contaminants from waste water by using composite bead comprising of saw dust, bentonite clay and natural soil with enhanced adsorption capacity. “Bentonite Clay is a unique clay due to its ability to produce an ‘electrical charge’ when hydrated. Upon contact with fluid, its electrical components change, giving it the ability to absorb toxins due to their higher surface area and Fe/Mn/aluminum oxide content. Bentonite is known for its ability to absorb and remove toxins, heavy metals, impurities, and chemicals“, he said adding that the major advantages of using sawdust in forming composite beads is that it works as pore formers and also possesses low-cost, high efficiency, minimization of chemical and biological sludge, regeneration of bio-sorbent, no additional nutrient requirement and possibility of metal recovery.
According to him, the composite beads are added in wastewater to adsorb heavy metal contaminants. In experiments it was found that it is able to remove 99.99% heavy metals from wastewater within half-an-hour. These beads are very helpful for cleaning water containing contamination of cationic heavy metals like nickel. They are proved to be inexpensive to use in daily life as compared to other available material for treating water.
