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Virus Removal in Biosand Filters for Rural Mayan CommunitiesEPA Grant Number: SU834754
Title: Virus Removal in Biosand Filters for Rural Mayan Communities
Investigators: Nguyen, Thanh (Helen) H.
Institution: University of Illinois at Urbana-Champaign
EPA Project Officer: Nolt-Helms, Cynthia
Project Period: August 15, 2010 through August 14, 2012
Project Amount: $75,000
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet - Phase 2 (2010) Recipients Lists
Research Category: Pollution Prevention/Sustainable Development , P3 Challenge Area - Materials & Chemicals , P3 Challenge Area - Pollution Prevention , P3 Challenge Area - Water , P3 Awards , Sustainability
The Mayan community of Socorro, Guatemala embodies the plight of the 884 million people who lack access to safe water supplies worldwide. The 450 residents are plagued with water- and soil-borne pathogens that cause problems such as scabies, diarrhea, dysentery, hepatitis A, giardiasis, shigellosis, amoebiasis, and soil transmitted helminthes infections, all of which prevent sustainable development of the infrastructure and local economy. In winter 2010, five students from the University of Illinois at Urbana-Champaign traveled to Socorro, Guatemala to initiate the implementation of 150 biosand filters, a popular point of use water treatment system used by approximately 3 million people across the world. Although biosand filters effectively remove bacteria, protozoa, and helminthes, they only demonstrate 0.5-2 log removal of viruses, insufficient per US EPA standards. At the University of Illinois, a team of approximately 20 interdisciplinary undergraduate students investigate the enhanced removal of viruses by biosand filtration utilizing sand media amended with zero-valent iron.
Earlier studies show that iron oxides create positively charged surfaces to which negatively charged viruses adsorb and possibly become inactivated due to electrostatic interactions. The research utilizes both small sand column studies and full-scale concrete biosand filters to investigate the virus removing capabilities of iron-amended biosand filters. Initial studies performed using four glass columns and aquifer water seeded with MS-2 bacteriophage found that, after 71 days, each column containing a sand/iron mix achieved approximately 6-log10 removal, compared to 0.5-log10 removal by the fourth column containing no iron. Concrete filters utilizing sand media amended with commercially available iron shavings displayed an average of ~6-log10 removal of MS-2 phage and, in addition, concrete filters utilizing sand media amended with steel wool, a widely commercially available source, demonstrated comparable removal efficacy. Future research will take place in the community of Socorro with the establishment of an on-site laboratory for the analysis of microbial reductions by iron amended biosand filters charged daily with the community’s tap water seeded with pathogen surrogates.
It is expected that daily water quality variations from a water source will not significantly impact the virus removal efficacy of the iron amended biosand filter with proper operation and maintenance. The wide availability of a safe iron source material and the success of past biosand filter entrepreneurial businesses suggest that iron-amended biosand filters will become a feasible commercial enterprise. Lastly, the minor and inexpensive modification to the biosand media for the over 350,000 biosand filters already existing will positively impact the approximately 3 million current users and millions more in future generations.
Supplemental Keywords:waterborne pathogens, virus, iron oxide, biosand filter, filtration,
Relevant Websites:Phase 1 Abstract
Phase 1 Final Report