TY - JOUR
T1 - Hydraulic loading rate effect on removal rates in a BioSand filter
T2 - A pilot study of three conditions
AU - Kennedy, T. J.
AU - Hernandez, E. A.
AU - Morse, A. N.
AU - Anderson, T. A.
N1 - Copyright:
Copyright 2013 Elsevier B.V., All rights reserved.
PY - 2012/9
Y1 - 2012/9
N2 - Safe drinking water is a luxury to approximately 800 million people worldwide. The number of people without access to clean water has been reduced, thanks to technologies like the biosand filter (BSF), an intermittently operated household scale slow sand filter. The BSF outlet (control diameter 0.5″) was modified in this study by reducing the outlet diameter (0.37″ and 0.25″) to determine the effects of hydraulic retention time on removal rates. Filters were dosed with 20 L of spiked lake water daily and observed for pH, dissolved oxygen (DO), fecal coliforms (FC), turbidity, nitrate, nitrite, sulfate, and ammonia until initial flow rates dropped below 0.2 L/min. Consistent with previous studies, the average turbidity was reduced to below 1 NTU; the average DO was reduced by 45 %. No significant difference was observed between the modified BSFs and the control BSF. Removal efficiency of FC was not significantly different between the modified BSFs (93.3 % and 91.9 %) and the control BSF (89.6 %). Mean FC reduction during the startup period (17 days) was significantly greater in the modified 0.25″ BSF when compared with the control during the same time period. After the first 17 days of the experiment, the average reduction efficiency of all filters was >97 %. While source water was below guideline values for nitrate, nitrite, ammonia, and sulfate during the course of the experiment, total nitrogen reduction was observed. The reduction indicates that the plastic BSF is capable of accomplishing limited denitrification during the filtering process.
AB - Safe drinking water is a luxury to approximately 800 million people worldwide. The number of people without access to clean water has been reduced, thanks to technologies like the biosand filter (BSF), an intermittently operated household scale slow sand filter. The BSF outlet (control diameter 0.5″) was modified in this study by reducing the outlet diameter (0.37″ and 0.25″) to determine the effects of hydraulic retention time on removal rates. Filters were dosed with 20 L of spiked lake water daily and observed for pH, dissolved oxygen (DO), fecal coliforms (FC), turbidity, nitrate, nitrite, sulfate, and ammonia until initial flow rates dropped below 0.2 L/min. Consistent with previous studies, the average turbidity was reduced to below 1 NTU; the average DO was reduced by 45 %. No significant difference was observed between the modified BSFs and the control BSF. Removal efficiency of FC was not significantly different between the modified BSFs (93.3 % and 91.9 %) and the control BSF (89.6 %). Mean FC reduction during the startup period (17 days) was significantly greater in the modified 0.25″ BSF when compared with the control during the same time period. After the first 17 days of the experiment, the average reduction efficiency of all filters was >97 %. While source water was below guideline values for nitrate, nitrite, ammonia, and sulfate during the course of the experiment, total nitrogen reduction was observed. The reduction indicates that the plastic BSF is capable of accomplishing limited denitrification during the filtering process.
KW - Biosand filter
KW - Denitrification
KW - Developing world
KW - Point of use
KW - Water treatment
UR - http://www.scopus.com/inward/record.url?scp=84865478976&partnerID=8YFLogxK
U2 - 10.1007/s11270-012-1215-4
DO - 10.1007/s11270-012-1215-4
M3 - Article
AN - SCOPUS:84865478976
VL - 223
SP - 4527
EP - 4537
JO - Water, Air, and Soil Pollution
JF - Water, Air, and Soil Pollution
SN - 0049-6979
IS - 7
ER -