existence of acid humic in water resources is undesirable and causes carcinogenic component in disinfection process due to reaction with chlorine. due to their cost-effectiveness and higher physical resistance than activated carbon, natural zeloites are used for removing various pollutants. . in the present study, iranian natural zeolite modified with cetylpyridinium bromide (cpb) was investiga...

The Box-Behnken Design of the response surface methodology was employed to optimize four most important adsorption parameters (initial arsenic concentration, pH, adsorption temperature and time) and to investigate the interactive effects of these variables on arsenic(V) adsorption capacity of mesoporous alumina (MA). According to analysis of variance (ANOVA) and response surface analyses, the e...

The biosorption of nickel(II) ions by deactivated protonated yeast was investigated with respect to the initial pH and initial metal ion concentration. The kinetics of sorption was also followed based on the amounts of metal sorbed at various time intervals for different yeast doses. The equilibrium data could be fitted by the Langmuir isotherm model. The adsorption capacity was pH dependent wi...

Paper mill effluent (PME) was used as an organic feedstock for production of biohydrogen via dark fermentation using heat-shock pretreated anaerobic sludge under mesophilic conditions. The influence of substrate concentration (5, 10 and 15 g-COD/L) and the initial pH (5 and 7) on the efficiency of dark hydrogen fermentation from PME were investigated. The highest hydrogen yield of 55.4 mL/g-COD...

the research aimed to apply the taguchi method for techno-economical evaluation of cr+6 removal using the electro-coagulation process with the aid of two different coagulants (fecl3 and pac). taguchi orthogonal array l27 (313) was applied for analyzing the effect of four variables including initial ph, reaction time, current density and coagulant types in an attempt to improve the chromium remo...

in this research degradation and mineralization of ortho-toluidine (ot) in the wastewater of petrochemical industries was investigated by uv/tio 2 process in a batch recirculating photo reactor. the influence of different variables such as initial ph, amount of tio 2 and initial concentration of ot on the reaction rate was investigated. in optimum conditions (1.75 g/l of catalyst, ph at 7 and i...

the present work is focused on the degradation of 4-chloro-2-nitrophenol in aqueous solution containing nano titanium dioxide, hydrogen peroxide and the combination of nano-tio2/h2o2. the effect of experimental parameters, such as the amount of nano- tio2 concentration of h2o2, initial concentration of 4-chloro-2-nitrophenol and ph on the reaction was investigated. experimental data obtained un...

the aim of this study is to investigate the nitrate adsorption on granular ferric hydroxide (gfh). the effect of factors such as initial concentration of nitrate, ph, contact time, and adsorbent mass were determined. the study was done in laboratory–scale in which synthetic nitrate solutions in a batch reactor were placed in contact with the adsorbent to model adsorption kinetics. it was found ...

halophilic and halotolerant microorganisms are good candidates for decolorization of azo dyeswhich are routinely used in the dyeing process in textile industries. in this paper, theoptimization of biological decolorization of synthetic dye solutions containing remazol black bby the previously isolated halophilic bacterium halomonas sp. d2 is investigated. in a primaryinvestigation using a one-f...

In 2001 the U.S. Environmental Protection Agency (EPA) lowered the Maximum Contaminant Level for arsenic from 50 μg/L to 10 μg/L. Public water suppliers are required to comply with the lower standard by January of 2006 and several thousand water systems nationally are looking for efficient and inexpensive ways to remove arsenic. Ferric coagulation/filtration and ferric coagulation/microfiltrati...