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ELECTROCHEMICAL ARSENIC REMEDIATION IN RURAL BANGLADESH
Impact/Purpose:
rb arsenic, due to (i) an increase in the rate of rust production (by factors of 10 to 100 over natural rusting rate of metallic iron), and (ii) the rapid oxidation of As(III) in the water to the more favorable As(V) which binds much more readily to rust. Thus the employment of a small amount of electricity leads to a large advantage in efficiency, lowering the cost and producing far less waste than chemical adsorbents. In addition, the electrodes are self-cleaning if current is alternated, reducing maintenance and eliminating the need for corrosive acids or toxic chemicals for regeneration.
The objective of this project is to combine the attractive properties of ECAR with an economically sustainable model for clean water delivery to help mitigate the arsenic crisis in Bangladesh.
rb arsenic, due to (i) an increase in the rate of rust production (by factors of 10 to 100 over natural rusting rate of metallic iron), and (ii) the rapid oxidation of As(III) in the water to the more favorable As(V) which binds much more readily to rust. Thus the employment of a small amount of electricity leads to a large advantage in efficiency, lowering the cost and producing far less waste than chemical adsorbents. In addition, the electrodes are self-cleaning if current is alternated, reducing maintenance and eliminating the need for corrosive acids or toxic chemicals for regeneration.The objective of this project is to combine the attractive properties of ECAR with an economically sustainable model for clean water delivery to help mitigate the arsenic crisis in Bangladesh.
Arsenic in drinking water is a major public health problem threatening the lives of over 140 million people worldwide. In Bangladesh alone, between 35-77 million people drink arsenic-laden water from shallow wells, leading to what has aptly been called the largest mass poisoning of a population in history. Over one million deaths are expected due to arsenic-related cancer in Bangladesh. Millions more will suffer from arsenic-related medical conditions unless something is done.
The primarily rural population of Bangladesh is too poor to afford arsenic remediation techniques that are cost effective only on large scales. Current technical approaches to low-cost arsenic removal involve the addition of chemical adsorbents, which frequently exhibit one or more of the following environmentally degrading qualities: toxicity, use of strong alkalies or corrosive acids to regenerate, production of large quantities of arsenic-laden toxic waste, a short shelf life, and/or the need for an extensive supply chain with corresponding greenhouse gas emissions. In addition, these technologies are often deployed as point-of-use devices, to be operated and maintained by the user. Point-of-use systems have been plagued by high abandonment rates after a short time due to difficult maintenance or operation, lack of time to devote, and low cultural acceptability. A new model is needed to ensure sustainability of water treatment for future generations.
Electrochemical Arsenic Remediation (ECAR) overcomes many of the obstacles of chemical adsorbents and can be used affordably and on a small-scale, allowing for rapid dissemination into rural Bangladesh. In EC, electricity is used to continuously dissolve an iron anode, forming corrosion products (collectively called ferric (hydr)oxides or rust). Thus the arsenic adsorbent is manufactured at the time of use - eliminating the need for a costly supply chain. In addition, this process greatly enhances the capacity of rust to adso
Description:
In Year 1, we built a bench-scale continuous flow prototype (dubbed “Sushi” for its sushi-like electrode roll) and completed preliminary field trials in Bangladesh. We were also able to leverage additional funding to complete preliminary field trials in arsenic-affected Kandal Province, Cambodia. Across both locations, we were able to reduce arsenic below the WHO limit of 10 ppb in every tested sample (11 well samples total, with initial arsenic concentrations ranging from 80 to 760 ppb).
We have identified a location and partnerships to perform an extended technical trial of a 100 L ECAR prototype device in Armirabad Village, Murshidabad District, West Bengal, India (just across the border from Bangladesh). The site was chosen based on fruitful and positive collaborations we have formed with Jadavpur University, Kolkata, Kandi Raj College in Murshidabad, and an NGO local to Amirabad village known as BAJS. We also have positive relationships with the Arsenic Task Force (Government of India) and the District Magistrate of Murshidabad – all key to running a successful field trial.
In Berkeley, our student team has built and tested a 20 L and 100 L prototype device for the extended field trial. The 20 L device has been used to optimize electrode configuration, study different low-cost coagulants, and choose a low-power agitation method for the 100 L prototype.
Our team worked with a team of 6 graduate students in Haas School of Business to develop marketing tools aimed at finding business partnerships for our Pilot Project and beyond. We created a pamphlet, a business oriented marketing document, an FAQ document, and a 5-minute pitch presentation. University of California’s Tech Transfer Office is currently in discussions with several promising companies interested in licensing the ECAR device for Bangladesh and India.