Osmotic backwash experiments were conducted and analytical model was developed in attempt to describe the backwash mechanism. A single unit of a spiral wound RO membrane was used in the experiments. The RO membrane was fed by salted water solution. Permeate flux characteristics of the membrane were determined through steadystate RO experiments. Then the system was shiRed immediately to a backwa...

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 effect of backwash frequency (15, 30 and 60 min) and influent flux (3.75, 7.50 and 11.25 L/h/m) on fouling amelioration in an innovative external side-stream dead-end microfiltration anaerobic membrane bioreactor (AnMBR) for the treatment of domestic wastewater at 25EC was investigated. During 6 months of reactor operation, a constant COD removal of 88% and an accumulation of 350 mg TSS/L/d...

Identification of Tsunami deposits has long been a controversial issue among geologists. Although there are many identification criteria based on the sedimentary characteristics of unequivocal Tsunami deposits, the concept still remains ambiguous. Apart from relying on some conventional geological, sedimentological, and geoscientific records, geologists need some alternative "proxies" to identi...

The membrane filtration with inside-out dead-end driven UF-/MF- capillary membranes is an effective process for particle removal in water treatment. Its industrial application increased in the last decade exponentially. To date, the research activities in this field were aimed first of all at the analysis of filtration phenomena disregarding the influence of backwash on the operation parameters...

Anaerobic membrane bioreactor (AnMBR) can produce high-quality effluents through effective solid-liquid separation using microfiltration. During the operation of the membrane bioreactor system, membrane fouling is one of the main problems. Several models have been proposed to understand the mechanisms of fouling of the membrane. Usually, cake formation and pore blocking are found to be the main...

In this study, a full-scale membrane bioreactor (MBR) was monitored over a period exceeding 6 months. Two common chemical cleaning modes, chemically enhanced backwash and clean in place, with sodium hypochlorite were monitored with respect to microorganism log removal value (LRV). Overall, impact to microorganism LRV for virus, bacteria and protozoa due to cleaning was negligible with respect t...

A model was developed and calibrated to experimental data, to formulate a theoretical description of nitrification in bead filters. The model results were consistent with the literature, indicating that the inverse relationship between solids accumulation and nitrification is mediated by an oxygen limitation. This result was central to an explanation of why differing optimal backwash intervals ...

Seawater ultrafi ltration (UF) as a pretreatment of reverse osmosis (RO) process in a thermal power plant was investigated using a 100 kDa hollow fi ber membrane. The choice of the UF physical backwash conditions remains arbitrary or ensuing from a sensibility study. As the optimum must take into account the factors interactions, we led a response surface study to analy...