Prechlorination is used as an initial step in water purification for public supply. One of the drawbacks of the prechlorination is the reaction between natural organic matters with chlorine forming trihalmethanes. This study aims at evaluating the performance of granular activated carbon (GAC) with sand as a dual filtering media with different depths on removal of trihalomethanes (THMs) for imp...

background: increased impervious surfaces in urban areas not only increase runoff volume and peak flow, but also worsen urban storm water pollution. the polluted runoff has many adverse impacts on human life and environment. the purpose of this study was to investigate and compare the efficiency of sand columns coated with nanoparticles of iron oxide in the presence and absence of a magnetic fi...

The removal of contaminants in slow sand filters occurs mainly in the colmation layer or schmutzdecke a biologically active layer consisting of algae, bacteria, diatoms and zooplankton. A ripening period of 6 8 weeks is required for this layer to form, during which time filter performance is sub-optimal. In the current study, an environmental scanning electron microscope was used to visualise t...

Viral contamination of public waters is a leading health concern around the world, including in Minnesota where cold climate, abundant onsite systems on poor or thin soils, and abundant surface water resources present a significant risk of wastewater pathogens reaching sensitive water sources. Three alternative onsite treatment systems, a sand filter, peat filter and subsurface-flow constructed...

Biological rapid sand filters are often used to remove ammonium from groundwater for drinking water supply. They often operate under dynamic substrate and hydraulic loading conditions, which can lead to increased levels of ammonium and nitrite in the effluent. To determine the maximum nitrification rates and safe operating windows of rapid sand filters, a pilot scale rapid sand filter was used ...

ground water is the major source of drinking water in rural and semi-urban areas of assam. it contains an excessive amount of iron (1 to 10 mg/l). people living in rural and semi-urban areas of assam uses indigenous household iron filter units – developed using community prepared wooden charcoal (cpwc) and river sand (rs) as filter media. cpwc and rs processed and respectively termed as process...

This study describes the new design and function of a modified version of a traditional slow sand filter. The Submerged Pond Sand Filter is built inside a pond and has a vertical as well as a horizontal flow of water through a sloped filter opening. The filter provides treated drinking water to a rural Indian village. The filter has functioned with minimal maintenance for five years without bei...

Escherichia Coli is the ubiquitous microorganism contaminating the drinking water. This study is using granular bed filtration as a vigorous, simple and economical method to prevent the penetration of bacterial contamination, by discovering an alternative filter media from local source namely the burnt oil palm shell (BOPS). The result indicated that dual media BOPS/sand were higher reduction a...

The decimal elimination capacity (DEC) of slow sand filters (SSF) for viruses, bacteria and oocysts of Cryptosporidium has been assessed from full-scale data and pilot plant and laboratory experiments. DEC for viruses calculated from experimental data with MS2-bacteriophages in the pilot plant filters was 1.5–2 log10. E. coli and thermotolerant coliforms (Coli44) were removed at full-scale and ...