2016 R&D 100 Award Winner
APPLICATIONS OF TECHNOLOGY:
- Drinking water treatment
- Fluoride ion removal from industrial-waste effluent streams
- Low cost materials and processing
- Scalable for rural communities
- Effective pH control
- Avoids use of toxic chemicals for media regeneration
- Very high water recovery
Berkeley Lab researchers led by Ashok Gadgil have developed a remediation technology using bauxite material that can treat fluoride-contaminated groundwater to achieve the World Health Organization (WHO) permissible limit for fluoride in drinking water of 1.5 ppm. The technology does not require intensive bauxite processing to yield aluminum-based adsorbents such as activated alumina filters and aluminum electrocoagulation that are unaffordable for low-income populations. Alumina, activated alumina, and aluminum respectively cost 10 times, 50 times, and 100 times more than raw bauxite ore.
Existing defluoridation technologies use membrane-based reverse osmosis, which wastes up to 50% of water in the reject stream, or an activated alumina filtration process, requiring expensive thermal activation or energy intensive chemical digestion to remove fluoride from drinking water as well as toxic materials for media regeneration. While these technologies are effective, they are not sustainable in rural remote areas because they are labor intensive, cost-prohibitive, and unreliable or because materials are difficult to source locally or are culturally inappropriate, as in the case of bone char.
Fluoride contamination affects 200 million people worldwide, causing anemia, poor nutrient absorption, degradation of tooth enamel, and severe bone deformities in children. The primary cause of high fluoride levels is the dissolution of fluoride-rich granitic rocks. Excess geogenic fluoride in groundwater is reported in India, Sri Lanka, China, the East African Rift Valley, the Middle East, northern Mexico, and central Argentina. This Berkeley Lab technology is poised to advance the cause of clean water in developing countries.
FOR MORE INFORMATION:
Cherukumilli, K., Delaire, C., Amrose, S., and Gadgil, A. Factors governing the performance of bauxite for fluoride remediation of groundwater, Environmental Science & Technology, January 20, 2017.
DEVELOPMENT STAGE: Samples of synthetic groundwater with high fluoride content (5 ppm and 10 ppm) reached potable levels (below 1.5 ppm fluoride) after treatment with the Berkeley Lab technology. Groundwater from Nalgonda in the Indian state of Telangana was successfully treated after pH adjustment.
STATUS: Published U. S. Patent Application 15/777,128 (Publication No. 2018/0327280). Available for licensing or collaborative research.
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