Removal of cyanide from aquatic solution by using of iron and copper powder: equilibrium and kinetic study

Industrial wastewater included the cyanide is one of the important sources of environmental pollution which founded in Industrial wastewater which are harmful for human health and environment. Therefore, the purpose of this research that was fundamental designed is investigation of Removal of cyanide from aquatic solution by using of iron and copper powder in experimental scale. At first, pilot was designed. Then, acquired pH optimum equal to 2,7 for copper and iron by variation pH= [2,4,6,8,12] and constant other parameters. The effect of initial cyanide concentration [40,60,80 mg/1], initial iron and copper dosage [0.08-1 g/100CC] and contact time [15-12 min] studied at the constant of optimum pH. The result showed removal efficiency Increased from 46.6% to 90.56% and 31% to 93.78% for copper and iron by increasing of contact time from 15 to 120 minute in constant conditions, respectively. Also result showed Removal efficiency decreased and increased by increasing initial cyanide concentration and initial iron and copper dosage. The results showed equilibrium data were explained acceptably by Langmuir isotherms and kinetic parameters were obtained by application of Langmuir and Hinshelwood equation. The results showed that removal of cyanide can be quick and effective done by iron and copper in experimental scale

Removal of divalent nickel from aqueous solutions by adsorption onto modified holly sawdust: equilibrium and kinetics

The removal of divalent nickel from aqueous solutions on modified holly sawdust was studied at varying contact times, pH, initial divalent nickel concentrations and adsorbent dose. Results showed the removal efficiency by increasing of pH increased and decreased with initial nickel divalent concentration. By increasing pH from 2 to 12 [equilibrium time= 240 min, adsorbent dose= 0.6g/100 mL, divalent nickel concentrations= 60 mg/L], the removal efficiency increased from 17.47% to 81.76%. Also removal efficiency was decreased from 98% to 19.3% by increasing of initial divalent nickel concentrations from 20 mg/l to 100 mg/L. Also the results showed the removal efficiency was increased by increasing of adsorbent dose and contact time. By increasing of adsorbent dose from 0.2 g/100CC to 1 g/100CC, the removal efficiency increased from 32.78% to 99.98%. The removal efficiency increased from 34.7% to 83.67% by increasing of contact time from 5 min to 240 min. Experimental equilibrium and kinetics data were fitted by Langmuir and Freundlich isotherms and pseudo-first-order and pseudo-second-order kinetics models, respectively. The results show that the equilibrium data follow Langmuir isotherm and the kinetic data follow pseudo-second-order model. The obtained maximum adsorption capacity was 22.47 mg/g at a pH 7. The results show that the modified holly sawdust can be used for the treatment of aqueous solutions containing nickel as a low cost adsorbent

Removal of reactive black 5 [RB5] dye from aquatic solution by using of adsorption onto synthesized sodium alginate magnetic beads

Industrial wastewater included the dyes one of the important sources of environmental pollution, that founded in loom wastewater which are harmful for human health and environment. Therefore, the purpose of this research was investigated removal of RB5 dye from aquatic solution by using of adsorption onto synthesized magnetic sodium alginate beads. At first, synthesized magnetic sodium alginate beads. Then, acquired beads optimum dosage equal to 18 g/l00CC, with constant other parameters. The effect of pH contact time and initial RB5 dye concentration was studied at the constant of beads [18 g/l00CC]. Results showed that removal efficiency was decreased by increasing of initial RB5 dye concentration. Also the results showed the removal efficiency was increased by increasing of adsorbent dose and contact time. The results showed data were explained acceptably by Langmuir isotherms and pseudo-second-order kinetics models respectively. The results showed that removal of RB5 dye from aqueous solution by using of magnetic sodium alginate beads can be done cheaper and effective

[Mechanism and removal efficiency of C.I. acid blake 1 by pumice stone adsorbent]

Treatment of colored wastewater is one of the important challenges of environmental engineers. Adsorption process is a key option for removal of organic matter from wastewater. The aim of present work was to investigate pumice stone as an adsorbent for removal of Acid Black 1 from aqueous solution. Removal of Acid Black 1 by pumice stone was investigated. Acid Hyrdo Chloric[HCL] 1 N was used to increse adsorbent porosity. Various parameters such as pH, initial dye concentration and contact time were studied. Results showed that removal of Acid Black 1 was increased by increasing of contact time and initial dyeconcentration although it was decreased by increasing of pH. Experimental data was best fitted to Longmuir isotherm model [r2>0.98]. Study of diffusion model revealed that intraparticle diffusion is rate-controlling step in removal of Acid Black 1 by pumice stone. The results indicated that pumice stone was a dominant adsorbent for Acid Black 1 removal

[Photocatalytic removal of hexavalent chromium and divalent nickel from aqueous solution by UV irradiation in the presence of titanium dioxide nanoparticles]

Industrial wastewater included the heavy metal is one of the important sources of environmental pollution. Hexavalent chromium and divalent nickel are founded in plating wastewater which is harmful for human health and environment. Therefore, the purpose of this research is investigation of photocatalytic removal of hexavalent chromium and divalent nickel from aqueous solution using UV/TiO[2] process in a batch system. At first, reactor was designed. Then, optimumdosage of TiO[2] was obtained equal to 1 g/L, with variation TiO[2] dosage at constant pH and initial concentrations of hexavalent chromium and divalent nickel. The effect of pH, contact time and initial concentration of hexavalent chromium was studied at the constant amount of TiO[2] [1gr/L]. The result showed that photocatalytic removal efficiency increased with increasing reaction time and TiO[2] dosage. In addition, it was found that removal efficiency of hexavalent chromium was decreased by increasing initial chromium concentration and pH. But, photocatalytic removal efficiency of nickel ion was increased and decreased by increasing of pH and initial nickel concentration, respectively. The results showed that UV/TiO[2] was an effective method in removal of hexavalent chromium and divalent nickel from aqueous solutions

Two-parameter isotherms of methyl orange sorption by pinecone derived activated carbon

The adsorption of a mono azo dye methyl-orange [MeO] onto granular pinecone derived activated carbon [GPAC], from aqueous solutions, was studied in a batch system. Seven two-parameter isotherm models Langmuir, Freundlich, Dubinin-Radushkevic, Temkin, Halsey, Jovanovic and Hurkins-Jura were used to fit the experimental data. The results revealed that the adsorption isotherm models fitted the data in the order of Jovanovic [X[2]=1.374] > Langmuir > Dubinin-Radushkevic > Temkin > Freundlich > Halsey > Hurkins-Jura isotherms. Adsorption isotherms modeling showed that the interaction of dye with activated carbon surface is localized monolayer adsorption. A comparison of kinetic models was evaluated for the pseudo-second order, Elovich and Lagergren kinetic models. Lagergren first order model was found to agree well with the experimental data [X[2]=9.231]. In order to determine the best-fit isotherm and kinetic models, two error analysis methods of Residual Mean Square Error and Chi-square statistic [X[2]] were used to evaluate the data

Photocatalytic disinfection of Coliform bacteria using UV/TiO[2]

There are great interests in photocatalytic oxidation of contaminants using titanium dioxide in recent years. The main objective of this research was to study photocatalytic disinfection of Coliform bacteria as water microbial pollution index using TiO[2] and a low pressure UV lamp in a batch reactor. The polluted water was prepared by adding a colony of Coliform in raw water and in separate stages was contacted with UV, TiO[2] and combination of them and various parameters such as contact time, pH and amount of TiO[2] were studied in terms of their effect on reaction progress. The results showed that in simultaneous presence of both UV ray and TiO[2], there was the most effective disinfection of Coliform. This study showed that 100% of Coliform was killed by irradiation for 60-75 min. in the presence of 0.8 gr 1[-1] TiO[2] in pH=7.0. Based on the results, UV/TiO[2] process may be effectively applied for disinfection of polluted water and can be suggested as a effective purifying method for water disinfection

[Removal of excess fluoride from water plants by poly aluminum chloride as a new coagulant]

The fluoride ions are commonly found in water resources. These ions should be in optimum levels for prevention of dental caries. However, the excess value can cause such health problems as fluorosis. The aim of the present study was to investigate the removal of excess fluoride ions by using poly aluminum chloride as a new coagulant that is used in water treatment plants. All experiments were conducted in batch system. Several combinations of parameters such as initial fluoride concentration [1.4, 2 and 2.4 mg/L], pH of solution [3, 7, 9], poly aluminum concentration [10, 20, 30, 40 mg/L], and exposure time [30, 60, 90 minute] were investigated. Various concentrations of poly aluminum chloride solution at different pH levels were added into 200 ml of fluoride solution, and samples were taken in predetermined time intervals and the final concentration of fluoride was determined by spectrophotometer at 570 nm. The results showed that, the highest removal was obtained at pH=7. In addition, it was observed that fluoride removal efficiency was higher in pH=5 than in pH=9. Also the results showed that, removal efficacy can be increased by increasing the poly aluminum chloride and the exposure-time. This study denoted that removal of high levels of fluoride ions can effectively be done by using poly aluminum chloride as a new coagulant. Its use is possible in water treatment facilities without any need for modification in water treatment plans