Removal of microorganisms through slow sand filtration of chlorinated ...

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Headloss minimization in slow sand filters is one of the most important considerations for its longer, efficient and economic runs, especially when used to treat ...
Removal of microorganisms through slow sand filtration of chlorinated vs. nonchlorinated secondary effluents. Syed Abdul Vakeel. Imran Civil Engineering 1997

Abstract Headloss minimization in slow sand filters is one of the most important considerations for its longer, efficient and economic runs, especially when used to treat nutrient rich secondary effluent. Previous studies on pilot filters have shown complications because of the short filter runs that result due to the uninhibited growth of the schmutzedecke layer. Chlorination of the secondary effluent prior to slow sand filtration was studied as a solution to this problem. A one-year field study was conducted to evaluate the effect of pre-chlorination of secondary effluents prior to slow sand filtration on the microbial removal efficiencies. Percent removal of the six indicators microorganisms by slow sand filters utilizing prechlorinating doses of 0, 5 and 15 mg/l, evaluated in this study, were 87.8, 98.6 and 99.9% for standard plate counts, 83.4, 98.2 and 99.9% for total coliforms, 86.0, 98.1 and 99.9% for fecal coliforms, 82.3, 97.5 and 99.9% for fecal streptococci, 78.0, 89.5 and 99.2% for C1. perfringens and 80.1, 91.3 and 99.5% for coliphages respectively. The corresponding headloss in these filters after 53 days of operation was 59.0, 28.5 and 8.6 inches respectively. Chlorination before slow sand filtration, seems to control the rapid growth of the schmutzedecke layer to an optimum limit that does not hinder microorganism removal and also controls the head loss.

Removal of Microorganisms through Slow Sand Filtration of Chlorinated vs. Non-chlorinated Secondary Effluents by Syed Abdul Vakeel Imran

A Thesis Presented to the FACULTY OF THE COLLEGE OF GRADUATE STUDIES KING FAHD UNIVERSITY OF PETROLEUM & MINERALS DHAHRAN, SAUDI ARABIA

In Partial Fulfillment of the Requirements for the Degree of

MASTER OF SCIENCE In CIVIL ENGINEERING

June, 1997