Potential release of soil colloids into groundwater has attracted considerable attention because of their association with heavy metals. Much effort has been focused on using colloid-depositionbased parameters (batch experiment) to predict colloid release in soils (column experiment), though they are two separate processes. In this paper, relative colloid stability ratio was estimated and used ...

Over 1.1 billion people in the world lack access to improved drinking water. Diarrhoeal and other waterborne diseases cause an estimated 1.87 million deaths per year. The Safe Water System (SWS) is a household water treatment intervention that reduces diarrhoeal disease incidence among users in developing countries. Turbid waters pose a particular challenge to implementation of SWS programmes; ...

A flocculating yeast Saccharomyces cerevisiae ura3 was transformed by the method based on treatment of intact cells with lithium acetate plus single-stranded carrier DNA using the shuttle vector pYAC4. The transformation efficiency was above 10(3) transformants per microgram of plasmid DNA which is similar to other described yeast transformation systems. Under selective pressure, the transforme...

Concentrating algal cells by flocculation as a prelude to centrifugation could significantly reduce the energy and cost of harvesting the algae. However, how variation in phenotypic traits such as cell surface features, cell size and motility alter the efficiency of metal cation and pH-induced flocculation is not well understood. Our results demonstrate that both wild-type and cell wall-deficie...

Flocculation onset, the time during the fermentative cycle at which the strains of Saccharomyces cerevisiae become flocculent, is an important factor in the brewing industry. The flocculation ability of Flo 1 phenotype (strain NCYC 869) remained practically unchanged throughout the growth and seems to be insensitive to the presence of nutrients of the culture medium. On the contrary, the floccu...

Two methods, centrifugation and flocculation, were evaluated to determine their efficiencies of recovery of Toxoplasma gondii oocysts from contaminated water samples. Demineralized and tap water replicates were inoculated with high numbers of sporulated or unsporulated T. gondii oocysts (1 x 10(5) and 1 x 10(4) oocysts). The strain, age, and concentration of the seeded oocysts were recorded. Oo...

Flocculation is a key unit operation in domestic and industrial water treatment, beneficiation of minerals, dewatering of sludges and in many industrial solid-liquid separation processes. Coagulants and flocculants are commonly employed as additives to induce aggregation and improve subsequent filtration or dewatering operations. The characteristics of these additives have a strong influence on...

The progressive reduction of velocitygradient to keep the flocculation rate as high as possible without breakage of flocsis called 'tapered flocculation'. In the present work, an attempt has been made to compare the performance of continuous tapered flocculationin conicaland cylindricaltanks. The efficiencyof conical flocculator was found to be higher than that of cylindrical flocculator, espec...

estuaries are considered as highly dynamic ecosystem that include the mixing or transition zone between river freshwater and saline water from oceans and seas. estuaries are very important aquatic systems by preserving the coastal biota. flocculation of metals during mixing of freshwater with saline water can be considered as the most important estuarine processes. due to flocculation process, ...

Many systems contain populations of individuals. Often, they are regarded as a lumped phase, which might, for some applications, lead to inadequate model predictive power. An alternative framework, Population Balance Models, has been used here to describe such a system, activated sludge flocculation in which particle size is the property one wants to model. An important problem to solve in popu...