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...

Engineering enhancement of slow sand filtration has been an enigma in large part because the mechanisms responsible for particle removal have not been well characterized. The presumed role of biological processes in the filter ripening process nearly precluded the possibility of enhancing filter performance since interventions to enhance biological activity would have required decreasing the qu...

A submerged biofilter (SBF) with 0.1 m of filter medium was maintained without backwash at four different water temperatures (14°C, 18°C, 22°C and 26°C) in four different recirculating systems stocked with green tiger shrimp (Penaeus semisulcatus). The ammonia removal profile and nitrification performance of the SBF was evaluated at feed loading rates of 2.65 g day at 14°C, 5.52 g day at 18°C, ...

During operation of most water treatment plants, spent filter backwash water (SFBW) is generated, which accounts about 2-10% of the total plant production. By increasing world population and water shortage in many countries, SFBW can be used as a permanent water source until the water treatment plant is working. This data article reports the practical method being used for water reuse from SFBW...

Little is known about the forces that determine the assembly of diverse bacterial communities inhabiting drinking water treatment filters and how this affects drinking water quality. Two contrasting ecological theories can help to understand how natural microbial communities assemble; niche theory and neutral theory, where environmental deterministic factors or stochastic factors predominate re...

A mechanistic model was derived for direct flow microfiltration (MF), one which lends more insight into the factors that control MF performance compared to a statistical curve-fitting procedure that is often used to estimate chemical cleaning intervals at pilot-scale. This theoretical approach to MF fouling was based on fundamental feed water, membrane, and cake characteristics and was shown to...

The removal of turbidity, particles, phytoplankton and zooplankton in water by crumb rubber filtration was investigated. A substantial reduction was achieved. Of the three variables, filter depth, media size and filtration rate, media size had the most significant influence. Smaller media size favored higher removal efficiency of all targeted matter. There was no apparent relationship between r...

Bryozoans are common biofoulers of underdrain filter nozzles in rapid gravity filters in water treatment works. A potential method for controlling bryozoan biofouling is the use of chlorine in backwash water. Repeatedly exposing bryozoan colonies with chlorine for 20 min every 24 h in an experimental setting, to replicate what would occur if the backwash was chlorinated, caused significant redu...