Comparison Of Effect Of Backwashing Methods On Overall Performance Of Rapid Sand Filter

IJEP 41(2): 202-206 : Vol. 41 Issue. 2 (February 2021)

Manoj H. Mota1,2 and P. S. Patil1*

1. Rajarambapu Institute of Technology, Department of Civil Engineering, Rajaramnagar, Islampur – 415 414, Maharashtra, India
2. Sharad Institute of Technology, College of Engineering, Department of Civil Engineering, Ichalkaranji – 416 115, Maharashtra, India

Abstract

Almost all water treatment plants in India use sand filter to purify water. Air scouring followed by conventional back-washing of filter media is a common process followed. Recently, a huge amount of research is done across the world in the field of back-washing and its significance on the overall performance on a sand filter. As a part of performance optimization, investigation of the effect of various back-washing techniques on overall filtration cycle is of great significance. The objective of the research explained in this paper is to compare few recently developed backwashing methods, like partial backwashing, filter resting and extended terminal sub-fluidized wash with the conventional method of backwashing. The comparison is based on the parameters, like water requirement for backwashing, the effect on ripening period and succeeding length of filter run. This study was carried out in association with Ichalkaranji Municipal Council by installing a pilot scale model at Ichalkaranji municipal water treatment plant having a total capacity of 108 MLD (millions of litre per day). As it is very difficult to judge one particular method out of these four as every method has certain advantages and certain limitations, one common performance indicator is derived based on various factors of comparison. This performance indicator is quite easy to apply, flexible enough to modify as per need and age of water treatment plant.

Keywords

Partial backwashing, Filter resting, Extended terminal sub-fluidized wash, Ripening period, Filter run length, Performance indicator

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