A Laboratory Investigation To Remove The Responsible For Clogging In Filtration Process

Abstract

This work was executed to design and construct a scale plant as part of a water treatment process by combining filtration and disinfection in one unit, using the local medium of sand, and a Pulse Electric Field-Low Voltage (PEF-LV). The Existing Rapid Sand Filtration (ERSF) is a purely physical method of drinking water purification. Biofilm formation takes place in the sand medium and comprises three steps i) bacterial cells settle onto the sand medium, ii) cells proliferate and secrete adhesive Extracellular Polymeric Substrates (EPS) and iii) cells detach and spread the biofilm to new locations, forming a soapy substance. In this study, we attempted to modify the ERSF by overcoming the drawbacks, in terms of the quality of the filtered water, EPS removal, as well as ease of operation–maintenance to make it more sustainable. The Disinfectant of Rapid Sand Filter (DRSF) incorporates the Pulse Electric Field-Low Voltage through the electrodes between the media. The experiments were done over the period from December 2019 to July 2020, at 8 hr/day as the running time The effectiveness of the various operational conditions of the DRSF and their findings were also analyzed, together with the observational, experimental and theoretical basis. The results showed that the optimum conditions for better performance of the DRSF include 30V, 3 pulses/second, AC pulse frequency, 50Hz, two pairs of electrodes in the sand medium, 100 L/hr influent flow rate, and parallel connection. Backwashing requirements for the ERSF was necessary every day, but in DRSF it was only once in every 7 days, at the same influent flow rates of 100 L/hr. Therefore, as the DRSF is to be backwashed less frequently, the operation and maintenance difficulties will be greatly minimized. The EPS, which was produced by the bacteria, was responsible for clogging the medium and causing the necessity to backwash every day in the ERSF. This microbial biomass reduced the pore space in the medium and increased the head loss. • Combining of filtration and disinfection in one unit (DF). • PEF-LV is an alternate water disinfection technology designed to avoid the use of chlorine. • Removal the responsible for clogging in the sand media (EPS). • Reduce the frequency of backwashing.