جستجوی مقالات مرتبط با کلیدواژه « حذف رنگزا » در نشریات گروه « مهندسی آب »

Textile industry wastewater in additions toxicity for organisms led to changes as decreased of water transparency and sunlight penetration and increase in chemical oxygen demand. Therefore, this study was carried out with the aim of removal of cationic red 46 dye from aqueous solution. For this purpose, the magnetic polymeric composite of graphite oxide nanoparticles (GO) and magnetic nanoparticles (MNP) in the matrix of polyacrilonitrile fiber (WPAN) at micro size by electroespining method was prepared. The XRD and SEM tests were used to determine the polymeric adsorbent characteristics. Magnetic properties of magnetic nanoparticles and polymeric adsorbent were measured at using vibrating sample magnetometer (VSM) analysis. Batch adsorption tests were optimized using the L16 orthogonal array of Taguchi method. The effects of variables including pH, adsorbent dosage, initial dye concentration and contact time on the dye removal were examined and the most influential factor in the removal of dye was pH. The adsorption isotherm data were well-fitted to Freundlich isothermal model (R^2= 0.99). Furthermor, adsorption kinetics of the dye followed pseudo-second-order model. Basic on these results, the polymeric composites was effective adsorbent for dye removal with efficiency over 96% and with quick separation for dye removal from aquatic solution.

In this study, bimetallic iron–nickel nanoparticles were obtained by chemical co-deposition of iron chloride with sodium boron hydride used as a strong reducing agent. The bimetallic nanoparticles thus obtained were then used to remove acid red 14 in a slurry system. Experiments were conducted to investigate such parameters as initial dye concentration, nano-particle dosage, pH, the time required for the nano-particles to be used after they are formed, the stirring speed, and the temperature required to reach optimum reaction conditions. Control experiments were subsequently performed under the optimum conditions thus determined to identify any other remaining factors involved. The optimum conditions included a temperature of 25±2 ºC, a newly synthesized nano-particle concentration of 0.05 g/L, an initial dye concentration of 200 mg/L, a pH level of 7.5, and a mixing duration of two minutes. The results indicated the high activity of the nanoparticles such that removal efficiencies equal to 79.39, 90.52, and 94.42 percent were achieved after 2, 30, and 240 minutes, respectively. Moreover, a COD removal of 72.61 percent was achieved after 4 hours of reaction.

In this study the effective parameters in removal of two azo dye including Reactive Black 5 (RB5) and Reactive Red 120 (RR120) using photocatalytic method (by TiO2 nanoparticles immobilized on the concrete support) were investigated. The effect of parameters such as photocatalyst amount, initial pH, dye concentration and UV power were determined. The results showed that increase of dye concentration and decrease in pH caused decrease in dye removal rate. In order to compare dyes removal, benzene and phenol rings removal were measured in UV254 and UV310 nm wavelengths, respectively. The results in the optimum conditions showed that RB5 removal rate was more than RR120 as the removal rate was reached to 99 percent after two and half hours.