Viral transport in deep-bed sand filters was studied by a new method that enables rapid and simple quantitation of labeled viruses. The residence time distribution (RTD) of viruses in the bed was compared to the RTD of a fluorescein dye under conditions that simulate a filter run. The characteristics of the RTD curves for the free dye and the labeled bacteriophages followed very different trend...

If you’ve ever found yourself struggling under a heavy pile of suitcases at the end of a holiday, spare a thought for the porters in some of the planet’s most remote locations. ‘When you start looking around, professional porters all around the world carry loads supported by their heads’, says Norman Heglund, from the Université catholique de Louvain, Belgium, who is fascinated by the technique...

This laboratory study examined the use of various wood materials as a carbon source in horizontal flow filters to denitrify nitrate-nitrogen (NO3-N) from a synthetic wastewater. The filter materials were: sawdust (Pinus radiata), sawdust and soil, sawdust and sand, and medium-chip wood chippings and sand. Two influent concentrations of NO3-N, 200 mg L(-1) and 60 mg L(-1), loaded at 2.9 to 19.4 ...

The cement industry is the major source of cement dust which contains heavy metals like nickel, cobalt, lead, chromium, arsenic and hazardous substances like dioxins and furans. Exposure to these substances can cause health problems to human, animals and vegetation. A continuous pilot scale quartz sand filter was constructed and uses to study the effect of important design parameters (temperatu...

The removal of microplastic from wastewater collected a plastic recycling facility was investigated, using laboratory scale sand-filter. Wastewater samples were before and after the onsite sand-filter, for characterization different polymer types, sizes, shapes. A considerable difference in characteristics concentrations microplastics observed sand-filtration, demonstrating differences source a...

Two species of earthworms, Lumbricus terrestris and Eisenia fetida, were used to de-clog sand filters purifying domestic sewage. The experimental set-up consisted of 6 filtration columns (4 research filters and 2 control filters) filled with fine sand (d60=0.2 mm, d10=0.1 mm). The sewage parameters at inflow to the filters were typical of the septic tank effluent. The filters were fed about 5.5...

Here we discuss the application of an edge detection filter, the Sobel filter of GIMP, to the recently discovered motion of some sand dunes on Mars. The filter allows a good comparison of an image HiRISE of 2007 and an image of 1999 recorded by the Mars Global Surveyor of the dunes in the Nili Patera caldera, measuring therefore the motion of the dunes on a longer period of time than that previ...

A three-pitcher (locally known as ‘3-Kolshi’) water filtration system made from locally available materials was tested for its efficacy in removing arsenic, other trace metals and anions from the groundwater of Bangladesh and the disposal of the filtering materials after the breakthrough was studied. In this filter, the first Kolshi has cast iron turnings, and sand, the second Kolshi has wood c...