The SAR Technology was developed by a consortium of European & Indian scientists led by Dr Bhaskar Sen Gupta, OBE & demonstrated at a location near Kolkata during 2005-06 (www.qub.ac.uk/tipot). The technology was subsequently replicated successfully inarsenic affected areas in West Bengal through World Bank Development Marketplace 2006 programme. The technology involves a very simple and easily adaptable process to remove arsenic and other heavy metals from groundwater using controlled oxidation without production of sludge & not using any chemicals at all.
This technology can transform the way arsenic is removed from groundwater in Ganges, Brahmaputra and Mekong delta region in India, Bangladesh, Cambodia, Nepal, Vietnam and Thailand. Also USA and Mexico are the two areas where this technology can be useful. Further R&D is being carried out by QUB-UK, NML-India & UM-Malaysia. The Arsenic status in USA has been given in the map.
Is there anyprobability of aquifers being clogged because of deposition of the arsenic-iron flocks ?
No. In SAR process aquifer will never get blocked. Precipitation and adsorption are competing processes. We perform a calculated start up process that ensures the aquifer is more of an adsorption bed rather than a precipitation bed. It can be controlled by controlling the redox potential drop across the zone of influence. Also, the iron-arsenic flocks are very minute in size & never aggregates to block soil pores.
A 2007 study found that over 137 million people in more than 70 countries are probably affected by arsenic poisoning of drinking water. (Associated Press - Aug, 2007)
The scientists predict that long-term exposure to present arsenic concentrations around the world will result in approximately 1.2 million cases of hyperpigmentation, 6,00,000 cases of keratosis, 1,25,000 cases of skin cancer & 3,000 fatalities per year from internal cancers. (Massachusetts Institute of Technology, 2002)
Want our help in mitigating the groundwater problem?
Besides Arsenic, SAR is now ready to remediate Iron, Manganese, Nitrate and Sulphate contaminated aquifers.
Word of Caution
Apparently, this technology is very simple to operate. However, the underlying science is extremely complex, as agreed by hydrogeologists, mineralogists, microbiologists and chemists. Uncalculated & unbalanced oxidation of the aquifer, without an expert's advice, can lead to As and Fe precipitation (resulting in As release in later date) rather than adsorption. Also, the abrupt change in redox potential and excess oxidation may destroy the existing bacterial population, making the whole process unstable and ineffective. Although no harm will be caused to the aquifer, but there won't be any benefit either.
Status of Arsenic in USA
Congratulations to Dr. Bhaskar Sen Gupta for being awarded
Officer of the Most Excellent Order of the British Empire (OBE) by her Majesty the Queen in 2012 for his contribution to Higher Education & International Env Research.