Tailings deposits from gold and uranium (U) mining in the Witwatersrand basin often contain elevated levels of radioactive and chemo-toxic heavy metals. Through seepage, dissolved U and other metals migrate from tailings deposits via groundwater into adjacent fluvial systems. The subsequent transport through flowing surface water is one of the most effective pathways of distributing contaminant...

To assess the effect of organic matter on the transport of Cryptosporidium parvum oocysts in a geochemically heterogeneous saturated porous medium, we measured the breakthrough and collision efficiencies of oocysts as a function of dissolved organic matter concentration in a flow-through column containing ferric oxyhydroxide-coated sand. We characterized the surface properties of the oocysts an...

the accurate estimation of reaeration rate coefficient, because of its effects on dissolved oxygen in rivers, is one of the most important initial steps of water quality management. the main goal of this paper is to evaluate the effects of reaeration rate coefficient on the river water dissolved oxygen, case study dinachal river, iran. to achieve these aims, water quality samples were collected...

Degradation of humic substances in water is important due to its adverse effects on the environment and human health. The aim of this study was modeling and investigating the degradation of humic substances in water using immobilized ZnO as a catalyst. ZnO nanoparticles were synthesized through simple coprecipitation (CPT) method and immobilized on glass plates. The immobilized ZnO nanocatalyst...

the effect of compost and humic acid in mobility and concentration of cadmium and chromium in contaminated soil were investigated. experiment was carried out with three levels of soil cadmium and chromium and two organic matters (compost and humic acid). the study was performed in a randomized complete block design with 3 replicates. results indicated that application of organic substances enha...

Concentrations and chemical composition of carbohydrates in dissolved organic carbon (DOC) and in extracellular polymeric substances (EPS) from brines, ice cores, gap layers in sea ice and associated surface waters were determined during 2004 and 2006 in the Weddell Sea, Antarctica. High levels of spatial heterogeneity were a common feature in these habitats, with DOC concentrations ranging fro...

Photocatalysis is a promising method for the disinfection of potable water in developing countries where solar irradiation can be employed, thus reducing the cost of treatment. In addition to microbial contamination, water normally contains suspended solids, dissolved inorganic ions and organic compounds (mainly humic substances) which may affect the efficacy of solar photocatalysis. In this wo...

Nitrogen is a main contaminant of wastewater worldwide. Novel processes for nitrogen removal have been developed over the last several decades. One of these is the partial nitritation process. This process includes the oxidation of ammonium to nitrite without the generation of nitrate. The partial nitritation process has several advantages over traditional nitrification-denitrification processe...

In this work, a validated stability-indicating ultra-high performance liquid chromatographic (UPLC) method has been developed for quantitative determination of related substances in Risperdal Consta. The chromatographic separation was achieved on a Waters BEH C18 column (2.1 × 100 mm, 1.7 μm) in an isocratic elution mode. The limit of quantification is 0.1 μg/mL, and the method is linear over t...