conventional sand filtration which has become a common wastewater treatment technology to satisfy regulations appointed for effluent reuse, suffers from the disadvantage of high energy for backwashing. the subject of this study is application of downflow floating media prior to coarse sand filtration, which requires less water for backwash. two pilots have been employed in two stages. for the f...

slow sand filtration (s.s.f) is a main process in the water treatment technology and generally considered as most appropriate for application in rural and small urban areas in developing countries. however, performance of the s.s.f is very sensitive to high turbidity levels. therefore, pretreatment is necessary for such waters. horizontal - flow roughing filtration (hfrf) and direct horizontal ...

the continuous filter is a kind of sand filter, which will operate without any interruptions for backwashing and also it accepts high-suspended solid levels in feed stream. fouled sand is continuously removed from the filter bed, washed and recycled back without interruption with filtration process. various samples of water with certain amounts of turbidity enter through a feed pipe and being d...

In this study, the pilot apparatus combined with sand filtration, ozonation and ultrafiltration was established. Wastewater from the secondary treatment effluent in the new-developed community was taken as the sample for looking into the feasibility of domestic wastewater reuse and recycling. The test results by sand filtration, sand filtration/ultrafiltration, sand filtration/ozonation, and sa...

The present study investigates major organic foulants in ultrafiltration (UF) of treated domestic wastewater and their removal in slow sand filtration. Identification and quantification of major foulants was conducted in labscale experiments. Quantified results suggest that biopolymers (large molecular protein-like and polysaccharidelike materials) are major organic foulants in UF. This conclus...

Most of the Tylenchulus semipenetrans larvae applied on the surface of four soils in pots 14.5-cm deep moved no further downward than 6.5 crn, and remained in the upper half of the pot. The percentage of second-stage larvae that developed into adult females on 'Homosassa' sweet orange in the soils were: sandy loam, 6.8% in the same soil with inoculation holes, 8.6%; loamy sand, 5.4%; coarse san...

The use of stormwater for managed aquifer recharge (MAR) has become one the most important ways to deal with water shortages and corresponding environmental geological problems, especially in north China. Fe (III) clogging porous media is a common significant problem that influences effect infiltration rate. This paper focuses on migration characteristics mechanisms iron hydroxides sand columns...

The dispersion of soilborne plant pathogens could be greater in closed soilless growing systems than in open ones. The effect of three soilless growing systems (open, closed and closed with slow sand filtration) on the dispersion of Verticillium dahliae propagules and the severity of the disease in strawberry (Fragaria × ananassa Duch.) has been analysed. V. dahliae dispersion in a closed syste...

A new concept for household and large-scale safe drinking water production is presented. Raw water is successively filtered through a series of sand and iron filters. Sand filters mostly remove suspended particles (media filtration) and iron filters remove anions, cations, micropollutants, natural organic matter, and micro-organisms including pathogens (reactive filtration). Accordingly, treatm...

Of utmost concern in storm water treatment today is the removal of dissolved phosphorus. One method to effectively determine the phosphorus removal capacity of different sand filtration media is controlled, well mixed experiments called batch studies. Batch studies with an initial phosphorus concentration typical of storm water were conducted at the University of Minnesota on C 33 sand, calcare...