204887 A pilot study to evaluate efficiency of plastic Biosand filtration units in removing coliforms from river water: A model for providing safe drinking water in rural communities in the developing world

Wednesday, November 11, 2009

Erica N. Boswell, BS , Department of Biology, Simmons College, Boston, MA
Elizabeth Scott, PhD , Biology Department, Simmons College, Boston, MA
David Gullette, PhD , Department of English, Simmons College, Boston, MA
BACKGROUND: The UN states that more than 1 billion people have no access to safe drinking water. Biosand filters provide an alternative option for people without access to safe water. This project explores the effectiveness of a plastic unit modeled after the Manz Filter. The objective of this project was to explore the effectiveness for bacterial removal of a plastic trash barrel as an alternative to concrete.

METHODS: This project involved undergraduate students majoring in Biology or Public Health. River water in Boston, MA was tested. Coliform contamination was analyzed before and after filtration. Water was collected three times a week and tested using a multiple tube fermentation test and Most Probable Number count. Presence of fecal coliforms was also evaluated.

RESULTS: Descriptive statistical analysis was performed. Mean and median coliform counts for unfiltered water were 291.25 and 290. Mean and median coliform counts for filtered water were 4 and 3 indicating that the filter produced significant reductions in coliform counts. All unfiltered samples were positive for fecal coliforms. They were absent from 6 out of 8 filtered samples giving a 75% removal efficiency.

CONCLUSION: The plastic Biosand filter proved to be effective in reducing the coliform count. However, CAWST indicates 97% removal efficiency for E. coli for the MANZ concrete system. Although our results do not meet that level of efficiency, we observed a significant trend towards removal of both coliforms and fecal coliforms. Further sampling will be performed to confirm the removal efficiency of the plastic filter unit.

Learning Objectives:
1. Evaluate the effectiveness of a plastic Biosand filter in removing coliform bacteria. 2. Identify the filtering capacity of a plastic Biosand filter in removing coliform bacteria

Keywords: Cost-Effectiveness, Water Quality

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I will be graduating in 2009 with a B.S. in Biology. I am currently writing an Honors Thesis on this project for further testing. Upon attending the APHA conference in 2009 I will have already presented material on this paper. I have experience building and installing Biosand filters in underpriviledged communitites of the surrounding area of Rivas, Nicaragua. My experiences volunteering with Simmons College and the Newton Sister City Project have influenced me to conduct research in the U.S. for a senior thesis project.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.

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