Abstract:
Expensive conventional water treatment technologies were barrier for rural areas because
they follow series of procedures with daily chemicals to get drinking water from impure
water. The cheap technology called slow sand filtration is a proven and sustainable water
treatment technology in rural communities. The objective of this research was to evaluate
the pollutants removal efficiency of slow sand filter units from the synthetic water. For
the achievement of this objective, four lab-scale filter columns were prepared from 4"
Polyvinyl Chloride pipe with a 90cm bed depth based on the fluctuating sand
characteristics of four setups. Each filter was adjusted to yield 20.75 l/day at a filtration
rate of 0.1m/h and effective size (0.22mm), coefficient of uniformity (2.95), and
coefficient of curvature (1.1) were used. The removal efficiencies of filters were in the
range of turbidity (73.8–91.1%), feacal coliform (98.45–99.91%), total coliform (95.17–
100%), total suspended solids (88.2–99.2%), and total dissolved solids (36.5–41%). The
first three filter's efficiency is affected by the total sand surface area, porosity, and
hydraulic conductivity regarding turbidity and total suspended solids removal. Feacal
coliform and total coliform removals depend mainly on biological activity in the filter
cake that rapidly formed at the top of filter media due to less porosity. Slow sand
filtration is simple to design, and operates. It had a heart full for the elimination of
pollutants in water in a single-stage filtration without using chemicals and could be
constructed by using locally available materials in rural areas. This is hopeful for use as an efficient water treatment system
