Abstract:
Water is one of the most precious natural resource, it is very extensively used by mankind. It is
an important and essential component of this universe and plays a vital role in the proper
functioning of the Earth’s ecosystems. In an era of increasing environmental concerns, water
scarcity admits the draw backs of chemical coagulants and poor sanitary facilities in lowest
income earning countries, the need to further develop natural coagulants as alternative
environmentally favorable water treatment chemicals. Therefore, this study was conducted to
investigate the surface water treatment potentiality of two natural coagulants, cactus(beles) and
Moringa stenopetala (seed of shiferaw). To conduct this study natural coagulants were collected
from local areas and grab or hand sampling technic was used to collect surface water sample
from awetu river. Based on this, coagulation and flocculation treatment process were applied by
using jar test apparatus to simulate the results. Design expert (11.0) was used for statistically
analyzing the experimental data with ANOVA and to evaluate the optimum condition or value of
both process factors with respective responses. So according to the experimentally analyzed
result, the optimum conditions and responses obtained from the numerical optimization system
for pH, coagulant dosage, stirring speed and stirring time were 2.5, 1.17g, 83.19rpm and
42.1min respectively when cactus powder was used as a natural coagulant. Under this optimum
conditions, about 70.22%, 47.10 % and 83.80% for color, COD and turbidity removal efficiency
was obtained respectively. And also in the same manner when Moringa stenopetala used as a
natural coagulant, the optimum conditions and responses obtained from numerical optimization
system for pH, coagulant dosage, stirring speed and stirring time were 10, 0.602g, 30.00rpm and
36.56 minute respectively. Then under this optimum condition, about 99.40%, 56.13%, and
96.56%, for color, COD and turbidity removal efficiency was obtained respectively. The effective
results were found using moringa stenopetala.
