Household Water Treatment and Safe Storage Factsheet: Source ...
Household Water Treatment and Safe Storage Factsheet: Source ...
Household Water Treatment and Safe Storage Factsheet: Source ...
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<strong>Household</strong> <strong>Water</strong> <strong>Treatment</strong> for Fluoride Removal<br />
<strong>Factsheet</strong>: Activated Alumina Filter<br />
Activated alumina filters can also consist of a<br />
domestic c<strong>and</strong>le water filter with an additional<br />
middle chamber holding a bag of activated<br />
alumina. The filter could also simply be an<br />
bucket, drum or column with a tap <strong>and</strong><br />
drainage pipe that is filled with activated<br />
alumina (see illustration below).<br />
The contact time of the filter is the amount of<br />
time the fluoride contaminated water is in<br />
contact with the activated alumina. Bulusu <strong>and</strong><br />
Nawlakhe (1988) conducted jar test<br />
experiments to determine the effect of contact<br />
time on fluoride removal. It was observed that<br />
the optimum contact time to reduce the fluoride<br />
level from 4.8 mg/L to 1 mg/L is 30 minutes.<br />
This can be used as a recommendation, but as<br />
of yet there is no formal recommendation for<br />
contact time.<br />
When the activated alumina media becomes<br />
saturated, meaning there are no more places<br />
for fluoride to adsorb to the media, the media<br />
can be regenerated using HCl, H 2 SO 4 , alum or<br />
NaOH. The wastewater created from this<br />
process should be disposed of in an<br />
appropriate manner away from water sources<br />
<strong>and</strong> human contact.<br />
Note: When 4% caustic soda (NaOH) is used<br />
for regeneration it needs to be followed by a<br />
neutralization step to remove residual NaOH<br />
from the filter.<br />
Three Common <strong>Household</strong> Units for Sorption Defluoridation<br />
(Credit: WHO, 2006)