Page 15 - WAPTAG TIMES_9th Aug2024.indd

RESEARCHERS DEVELOP SUSTAINABLE METHOD crustaceans—and doped with bimetallic (Fe and Al)
FOR REMOVING HEAVY METAL CONTAMINANTS hydroxide/oxyhydroxide. The adsorbent captures
FROM GROUNDWATER IN INDIA toxic inorganic arsenic through electrostatic forces and
complex formation.
Researchers at the Centre for sustainable Technologies A novel aspect of this technology is the recycling of the
(CsT) at the indian institute of science (iisc) have alkaline wash, used to regenerate the adsorbent bed. in
developed an innovative process for removing heavy the second step, the alkaline wash solution, containing
metal contaminants, such as arsenic, from groundwater. sodium hydroxide and arsenic, is separated using a
This three-step method, currently patent-pending, not membrane system. The sodium hydroxide is reused to
only effectively removes these contaminants but also regenerate the bed, while the arsenic is concentrated
ensures their safe disposal in an environmentally friendly for the next step: bioremediation.
manner, preventing untreated heavy metal-rich sludge
from re-entering the groundwater. in the bioremediation step, microbes found in cow
dung convert toxic inorganic arsenic to low-toxicity
Assistant Professor Yagnaseni Roy, who leads the lab organic arsenic via methylation. This process reduces
at CsT, explains, "in existing technologies, you can arsenic levels to below WHO standards within eight
remove arsenic and provide clean water, but there is days. The resulting cow dung sludge, containing the
often no adequate plan for preventing the re-entry of arsenic in an organic form, can be safely disposed of in
arsenic into the environment. Our process addresses landfills.
this problem comprehensively."
Roy’s team is also exploring the feasibility of using this
Reports indicate that 113 districts in 21 states in india system to remove other heavy metals. The system,
have arsenic levels exceeding 0.01 mg per liter, while which is easy to assemble and operate, has been tested
223 districts in 23 states have fluoride levels above in rural areas like Bhagalpur in Bihar and Chikkaballapur
1.5 mg per liter—both beyond the permissible limits in Karnataka, with promising results.
set by the Bureau of indian standards and the World
Health Organization (WHO). These contaminants pose The system's simplicity allows for community-level
significant health risks, necessitating their efficient implementation, offering an effective solution for
removal and safe disposal. managing groundwater contamination while generating
income for local operators.
The iisc team’s process begins with passing
contaminated water through a bed of biodegradable Source: Sustainable Separation Solutions (S3) Lab, CST,
adsorbent made from chitosan—derived from IISc

of climate change, increasing demand, and seawater
ENERGY RECOVERY ANNOUNCES $15M IN intrusion into diminishing groundwater supplies,
SWRO CONTRACTS IN INDIA
desalination projects have become essential to
Energy Recovery has secured $15 million in contracts supplement freshwater resources.
to supply its PX® Pressure exchanger® energy Rodney Clemente, senior Vice President of Water
recovery devices to seawater reverse osmosis (sWRO) at energy Recovery, highlighted the importance
desalination plants across india. These orders are of desalination in india. He emphasized that
scheduled to be shipped in 2024, marking a significant incorporating the PX device into desalination facilities
milestone in the company's commitment to addressing significantly reduces the energy consumption and
water scarcity in india. operational costs of producing fresh water. The PX
These sWRO plants are set to deliver over 670,000 recaptures wasted pressure energy within the sWRO
cubic meters of clean drinking water daily to various process, improving system performance and reducing
communities in india. This initiative is critical for carbon emissions by as much as 60%. Once installed,
india, which is one of the most water-stressed these projects are expected to prevent over 300,000
countries globally. Despite housing 18% of the world’s metric tons of carbon emissions annually, contributing
population, india has only 4% of the world’s water to a more sustainable future for india's water supply.
resources. As the country grapples with the impacts Source: ERI

AQUA PULse: iNDUsTRY NeWs & iNsiGHTs WAPTAG Times | 15