Reclaimed water is an important supplementary source for fresh water. Purification is necessary prior to utilization in order to minimize the pollution and human-health risk. A three-year experiment was carried out to study the removal of nitrogen and organics through a simulated soil aquifer treatment (SAT) system under continuous wetting and wetting/drying conditions. The removal performance ...

An unstructured finite volume numerical model is presented here for simulating shallow-water flows with wetting and drying fronts. The model is based on the Green’s theorem in combination with Chorin’s projection method. A 2-order upwind scheme coupled with a Least Square technique is used to handle convection terms. An Wetting and drying treatment is used in the present model to ensures the to...

expansive soils are considered a worldwide problem as they cause extensive damage tocivil engineering structures. an important characteristic of expansive soils is theirsusceptibility to volume change due to the phenomenon of wetting and drying. this paperpresets the effect of pore water quality on the swelling and shrinkage behavior of anexpansive soil during wetting and drying cycles. thirty ...

Unsaturated soils are commonly widespread around the world, especially at shallow depths from the surface. The mechanical behavior of this near surface soil is influenced by the seasonal variations such as rainfall or drought, which in turn may have a detrimental effect on many structures (e.g. retaining walls, shallow foundations, mechanically stabilized earth walls, soil slopes, and pavements...

Soil drying and re-wetting (DRW) occurs at varying frequencies and intensities during crop production, and is deliberately used in water-saving irrigation techniques that aim to enhance crop water use efficiency. Soil drying not only limits root water uptake which can (but not always) perturb shoot water status, but also alters root synthesis of phytohormones and their transport to shoots to re...

A test procedure to simulate and measure the actual behavior of solid and engineered wood products subjected to realistic cyclic moisture loading conditions was carried out at the Institute for Research in Construction (IRC), National Research Council Canada (NRC). The wetting and drying experiments on oriented strand board (OSB), showed that the rate of moisture absorption and the rate of dryi...

Cytokinins may reflect soil water status and regulate rice (Oryza sativa L.) grain filling. This study investigated the changes in cytokinin levels in rice plants and their relations with grain filling under alternate wetting and drying irrigation. Two 'super' rice cultivars were field grown. Three irrigation regimes, alternate wetting and moderate soil drying (WMD), alternate wetting and sever...

Expansive soils can be found in many parts of the world particularly in arid and semi-arid regions. These soilspose a significant hazard to civil engineering structures due to its high swelling and shrinkage potential. This paperpresents the results of an experimental program developed to investigate the effect of cyclic drying and wetting on theswelling potential of expansive soils with variou...

Global warming is expected to increase the frequency and intensity of droughts in the twenty-first century, but the relative contributions from changes in moisture supply (precipitation) versus evaporative demand (potential evapotranspiration; PET) have not been comprehensively assessed. Using output from a suite of general circulation model (GCM) simulations from phase 5 of the Coupled Model I...