the effect of hydraulic retention time in a range from 1.0-5.5 days was evaluated in a laboratoryscaleanaerobic fixed bed reactor packed with a hybrid material composed of tire rubber and zeolite. underthese conditions, cod removal efficiencies varied from 28.3% to 82.1%, respectively. over the more than 6months of operation, no clogging was observed. the results obtained demonstrated that this...

the effect of hydraulic retention time in a range from 1.0-5.5 days was evaluated in a laboratoryscaleanaerobic fixed bed reactor packed with a hybrid material composed of tire rubber and zeolite. underthese conditions, cod removal efficiencies varied from 28.3% to 82.1%, respectively. over the more than 6months of operation, no clogging was observed. the results obtained demonstrated that this...

a down-flow hanging sponge (dhs) reactor has been developed for sewage treatment, mainly in developing countries. this novel reactor employs polyurethane sponge material as a support medium, which promises a proliferation of a large amount of biomass, offering excellent pollutant removal capability. three types of sponge medium were evaluated with respect to water distribution and oxygen mass t...

introduction wetlands are classified into four kinds of flows as subsurface, surface, vertical, and hybrid flows. usually, wetlands are planted with common reed (phragmites australis), a rhizomatose plant of the graminae which produces a good yield in green biomass and whose roots can reach a considerable depth and plays a significant role in the wetland self-purification. the treatment efficie...

Removal efficiency of COD, NH4-N and PO4-P and NO3-N in five step SBR processes is widely influenced by hydraulic retention time of Anaerobic/Anoxic/Aerobic/Anoxic/Aerobic step of this system where the hydraulic retention time in each step is influence directly on removal efficiency of this system therefore the operator of this system cannot control on this system without experience or a contro...

The current research was focused mainly on the designing and construction of efficient laboratory scale hybrid constructed wetland (HCW) for the treatment of domestic wastewater. Parameters like COD, BOD5, PO4, SO4, NO3, NO2, and pathogenic indicator microbes were monitored after hydraulic retention time (HRT) of 4, 8, 12, 16, and 20 days. Treatment efficiency of HCW kept on increasing with the...

abstract pedotransfer functions (ptfs) are useful means of prediction many properties of the soil, and especially the hydraulic characteristics of this porous media. the main advantages of this functions, as compare to conventional methods used to directly estimate soil hydraulic properties, is that they are not time-cost consuming. different approaches such as classic linear and non linear reg...

Two biofilm reactors operated with hydraulic retention times of 0.8 and 5.0 h were used to study the links between population dynamics and reactor operation performance during a shift in process operation from pure nitrification to combined nitrification and organic carbon removal. The ammonium and the organic carbon loads were identical for both reactors. The composition and dynamics of the mi...