WASET
	%0 Journal Article
	%A Alaa Hussein Wadi
	%D 2010
	%J International Journal of Environmental and Ecological Engineering
	%B World Academy of Science, Engineering and Technology
	%I Open Science Index 38, 2010
	%T Effect of a Gravel Bed Flocculator on the Efficiency of a Low Cost Water Treatment Plants
	%U https://publications.waset.org/pdf/2790
	%V 38
	%X The principal objective of a water treatment plant is to
produce water that satisfies a set of drinking water quality standards
at a reasonable price to the consumers. The gravel-bed flocculator
provide a simple and inexpensive design for flocculation in small
water treatment plants (less than 5000 m3/day capacity). The packed
bed of gravel provides ideal conditions for the formation of compact
settleable flocs because of continuous recontact provided by the
sinuous flow of water through the interstices formed by the gravel.
The field data which were obtained from the operation of the
water supply treatment unit cover the physical, chemical and
biological water qualities of the raw and settled water as obtained by
the operation of the treatment unit. The experiments were carried out
with the aim of assessing the efficiency of the gravel filter in
removing the turbidity, pathogenic bacteria, from the raw water. The
water treatment plant, which was constructed for the treatment of
river water, was in principle a rapid sand filter.
The results show that the average value of the turbidity level of
the settled water was 4.83 NTU with a standard deviation of turbidity
2.893 NTU. This indicated that the removal efficiency of the
sedimentation tank (gravel filter) was about 67.8 %. for pH values
fluctuated between 7.75 and 8.15, indicating the alkaline nature of
the raw water of the river Shatt Al-Hilla, as expected. Raw water pH
is depressed slightly following alum coagulation. The pH of the
settled water ranged from 7.75 to a maximum of 8.05.
The bacteriological tests which were carried out on the water
samples were: total coliform test, E-coli test, and the plate count test.
In each test the procedure used was as outlined in the Standard
Methods for the Examination of Water and Wastewater (APHA,
AWWA, and WPCF, 1985). The gravel filter exhibit a low
performance in removing bacterial load. The percentage bacterial
removal, which is maximum for total plate count (19%) and
minimum for total coliform (16.82%).
	%P 75 - 80