background: as fluoride concentration in drinking water is one of the effective parameters in human health, finding the ways to remove excess amount of fluoride is very important in water supply projects. this study aimed to evaluate mendon bauxite mine in the removal of fluoride from drinking water. methods: this experimental study was conducted from may to october 2013 on synthetic and actual...

in this study, the ashes of poplar tree leaves are applied as an efficient, accessible and inexpensive biosorbent for the removal of heavy metals pb2+ and cu+2 in aqueous solutions. in the adsorption processes, the success of the ions removal highly depends on the level of several experimental factors such as ph, contact time, adsorbent dosage and temperature. therefore, a genuine statistical e...

in the present study, the kinetics of biodiesel production through transesterification of brassica carinata oil with methanol in the presence of potassium hydroxide is investigated by kinetic monte carlo simulation. the obtained results from simulation agree qualitatively with the existing experimental data. the kinetics data for each step of suggested mechanism are confirmed by simulation. by ...

background: the efficacy of nh4cl-induced activated carbon (nac) was examined in order to adsorb rr198, an azo reactive model dye, from an aqueous solution. methods: the effects of ph (3 to 10), adsorbent dose (0.1 to 1.2 g/l), dye concentration and contact time on the adsorption efficiency were investigated. results: the results showed that the removal of dye was highest at a solution ph of 7 ...

in this study, a new reaction system for quantitative determination of ascorbic acid was introduced. the developed method is based on inhibitory effect of ascorbic acid on the orange g-bromate system. the change in absorbance was followed spectrophotometrically at 478 nm. the dependence of sensitivity on the reaction variables including reagents concentration, temperature and time was investiga...

in this study metal oxide nano powder namely nio nanopowder was prepared .the producedmetal oxide was characterized and used as potential adsorbent for the removal of pb and zn from aqueoussolution. the rate of uptake of the pb and zn are rapid in the beginning and the time required for equilibrium adsorption is 120 min .the time of equilibrium as well as time required to achieve a definite fra...

a sensitive and selective kinetic-spectrophotometric method was developed for the determination of trace amounts of uric acid. the method is based on the inhibitory effect of uric acid on the oxidation of janus green by bromate in the presence of sulfuric acid. the reaction was followed spectrophotometrically by measuring the absorbance at 518 nm using the fixed-time method. under optimum exper...

biosorption of acidic dyes using the live fern azolla filliculoides was studied in a discontinuous system. dye parameters, dye initial concentration and contact time were studied in temperature range of 25-30 ?c and ph=7. it was shown that increasing the 23initial concentration of dye and its contact time resulted in decreasing the dye taking quantity by the absorbent. also, type of dye has an ...

for large and complex reacting systems, computational efficiency becomes a critical issue in process simulation, optimization and model-based control. mechanism simplification is often a necessity to improve computational speed. we present a novel approach to simplification of reaction networks that formulates the model reduction problem as an optimization problem and solves it using genetic al...

reactions of free radicals and reactive oxygen species (ros) with biological molecules in vivo play an important physiological role in many diseases. 2,2-diphenyl-1-picrylhydrazyl (dpph) is a stable free radical and often used as a routine reagent to evaluate the antioxidant capacity of an antioxidant. this study was undertaken to investigate the free radical-scavenging and antioxidant activiti...