Gujarat Central Univ finds microscopic solution for colossal e-waste problem

Ahmedabad, May 17, 2012: These tiny creatures love heavy metal. It’s not music we mean, but toxic metals like cadmium, mercury, chromium, lead and zinc: stuff that not only cause cancer but also trigger impairments in humans after they seep into our soil and groundwater.

A five-year research at the Central University of Gujarat (CUG) has zeroed in on a special group of microbes — mainly bacteria, fungi and actinomycetes — that not only munch on these deadly wastes but also turn the land useful by a process of bio-cleansing.

These heavy metals are present in electronic wastes at municipal landfill sites and in toxic industrial sludge. The CUG research has proposed the microbial bio-cleansing as a favorable option compared to dismantling and incinerating of ewaste; the latter two processes are costly and not eco-friendly.

The research team headed by the M H Fulekar, the dean of school of environment and sustainable development at CUG, found microbes from these sites that fed on such metals. These could be bacteria like bacillus, streptococci, salmonella, escherichia coli, pseudomonas, and micrococcus. Then there are fungi like aspergillus, mucor, penicillium rhizopus — microbes that are commonly found around us.

“The bio-cleansing science involves figuring out which microbes are doing what. It’s a difficult task because the bacteria are microscopic and there could be thousands of different kinds working together,” says Fulekar. “In this process we retrieved a special microbial consortium from the contaminated site and found that if bio-activated these microbes in groups can digest metals.” The combination of the microbes was tested on varying concentration of heavy metals, especially e-waste and even industrial sludge in laboratory conditions and it was determined that the microbes were 98.5 to 100 per cent efficient

The process is called bio-remediation and Fulekar says that the method can be applied to remove contaminants from soil, groundwater, surface water and sediments, and the air. The remediation goes a step further. Fulekar and his team — Bhawana Pathak and Pramila Sharma — have showed that the toxic land can be reclaimed by a combination of these microbes and growing ryegrass. The process is called Rhizosphere zone.

“Of course the grass cannot be fed to cattle as it will have absorbed all the microbe-digested heavy metals. But the land will be free of toxicity,” says Fulekar. He adds, “We will have to look towards nature to find a solution to the damage that we have done to our environment. This is a tiny step towards it.”

Hazardous components of E-waste
Mercury— Fluorescent tubes, flat screen monitors, door bells, thermostats
Sulphur—Lead-acid batteries Brominated Flame retardants—present in five different types of plastics used in electronic equipments
Cadmium – light sensitive resistors, corrosion resistant alloys, nickelcadmium batteries
Lead – CRT monitors, lead-acid batteries, some PVC articles
Beryllium oxide – Thermal grease in CPU of computers, ceramic windows, vaccum tubes and lasers