Formaldehyde (FA) is a very toxic pollutant. FA in indoor air has a negative effect on human health and should be removed by ventilation or by conversion to non-toxic products. The formaldehyde dehydrogenase (FdDH), a NADand glutathione-dependent enzyme from recombinant methylotrophic yeast Hansenula polymorpha, was tested for its ability to oxidize airborne FA. A continuous fluidized bed biore...

A self-design bioreactor system employing a fixed bed operation process with immobilized Bacillus subtilis AYC beads for NH4+-N removal from slightly polluted water was proposed. Polyvinyl alcohol and Na-alginate were used as a gel matrix to entrap Bacillus subtilis AYC to form the immobilized beads. The NH4+-N removal process was studied in a intermittent operation mode to examine the start-up...

Textile effluents are highly polluting and have variable and complex compositions. They can be extremely complex, with high salt concentrations and alkaline pHs. A fixed-bed bioreactor was used in the present study to simulate a textile effluent treatment, where the white-rot fungus, Trametes versicolor, efficiently decolourised the azo dye Reactive Black 5 over 28 days. This occurred under hig...

Introduction: The modeling aims to simulate or optimize a process in physical, chemical or biological environments and the derived model will provide a considerable assistance to generate data and predict unknown condition, in case of sufficient suitability. Unsuitable disposal and elimination of waste tires have polluted the environment and human life areas, it also have caused removal of a hu...

ethyl benzene used increasingly each year is the raw material of producing styrene monomer. this substanceis produced from benzene alkylation with ethylene or ethanol, depending on the availability and cost of rawmaterials. in this study benzene alkylation in the presence of ethanol in a catalytic fixed bed reactor inthree states of isotherm, adiabatic and non-isotherm-non-adiabatic is mathemat...

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 potential of six economically cheap agricultural waste materials, viz. rice husk, betel nutpeels, sugarcane molasses, tea waste, mustard oil cake and saw dust, was investigated for copper and leadremoval from aqueous solutions under batch and continuous conditions. the effect of ph, contact time,sorbent dose and initial metal ion concentration on the uptake of copper and lead was first exam...