نشریه کاربرد شیمی در محیط زیست
پیاپی 13 (زمستان 1391)

Background and Drinking water to the various aspects (quality of physical، chemical، bacteriological and radiological) is a desirable quality.. Chemical contaminants in drinking water are greater than the limit recommended in the long term can cause irreversible damage to the human will. Many health problems in developing countries، lack of safe drinking water. The purpose of this study was to evaluate the status of water quality parameters is the city of Mahabad. This study is a cross-sectional descriptive study was conducted and applied. During 1386 in the city of Mahabad in drinking water samples from several different sources (refinery output Dgrmvnd، Zalyvn، Phase 3 treatment Mahabad، and two areas of municipal water supplies) were taken. Physico-chemical parameters (position turbidity، pH، electrical conductivity، etc.) in the city of Mahabad Central Laboratory of Water and Wastewater، and analyzed according to standard methods of statistical analysis were used. The results of the analysis of samples that have been brought to the table and Charts it was estimated that in some cases the amount of color، conductivity، TDS also been Water standard is not cobalt water of the reason for this low efficiency of the treatment plant is. In general it can be concluded that the physicochemical state of Mahabad city drinking water is good condition.

In this study a simple and fast method was used for the synthesis of polydopamine (PD) nanoparticles. PD nanoparticles (44 nm) were synthesized from dopamine solution at alkaline pH (10mM Tris, pH 8/5) during 20h. The obtained dark-brown solution was dried to prepare very light polydopamine nanoparticales. Morphology and properties of nanostructured polydopamine was characterized by XRD, FTIR, SEM and TEM analysis. PD nanoparticles were used as an adsorbent for adsorption of Hg2+ ions from aqueous solutions. The effect of pH, ionic strength, adsorbent dosage, temperature, initial concentration and contact time on adsorption of adsorbents, from aqueous solutions using PD nanoparticles was investigated through batch experiments. The experimental results were analyzed using Langmuir, Freundlich and Temkin adsorption isotherms. The results obtained are well fitted in the linear forms of Freundlich and Temkin adsorption isotherms but Freundlich isotherm is better than Temkin isotherm. The adsorption capacity (qm) were found to be 1/072 mg Hg of the adsorbent. The batch sorption kinetics was studied for pseudo-first-order and pseudo-second-order reaction.

Photo catalytic studies have recently received a great deal of attention from different fields of study. Semi conductive heterogeneous photo catalyses and homogeneous photo catalyses such as Fe (III) salts can perform Redox reactions in the presence of different substrates by absorbing light in ultraviolet or visible area. This photo catalytic characteristic can be used to remove pollutants. With regard to the advantages of Fe (III) over heterogeneous catalysts, its photo catalytic activity was studied in the presence of potassium proxy di sulfate and the use of visible light as the light source. Experiments are carried out to examine the degradation of Methyl Orange dye as an azoic dye which has a wide application in textile industry. The degradation of the above mentioned dye occurred in different conditions and it was realized that light and Fe (III) are necessary for its degradation. Degradation reactions occurred in darkness too. The presence of -2 propanol as radical receptor didn’t have deterrent effect in these reactions. Studies show that Fe (III) and potassium proxy di sulfate solution has the degradation capacity for the above dye in the presence of light and this activity is, in some cases, due to hydroxide radical production.

Presented here is a synthetic strategy for a novel tetradentate Schiff base (H2L) with the formula C18H24O2N2 through a condensation reaction of 1,4-Bis(aminomethyl)benzene and acetylacetone with an approximate yield of 74%. Furthermore, the synthesis and characterization of two Schiff base complexes of Copper [Cu2(L)2] and Cobalt [Co2(L)2(H2O)4] is presented. Characterization of these complexes was performed using UV-VIS spectroscopy; IR spectroscopy; 13C & 1H NMR; and elemental analysis. The results of this analysis revealed that two ligand chains are attached to each metal ion in these complexes. The coordination geometries of the ligands around copper were shown to be squere planar around Cu and octahedral around Co.

Separation techniques, effective use of supercritical gases in the food industry has become so large several large companies already in supercritical separation methods employ purification and food production. The fields of the food industry in Germany has made considerable progress. For example, the extraction of the coffee and herbal tea Kafyny chewing tobacco extract using carbon dioxide under supercritical conditions is performed. In recent years, foods containing cholesterol have created many problems for human health. Cholesterol is easily soluble in supercritical carbon dioxide, and this promise is the separation of cholesterol from foods of animal origin.

In this study, the adsorption of 4-chloro-2-nitro phenol (4C2NP) onto bentonite (B) and modified bentonite by tetra-butyl ammonium iodide (TAI) and cetyltrimethyl ammonium bromide (CTAB) from aqueous solutions by considering the effects of various parameters such as contact time, adsorbent dose, pH, initial concentration of 4C2NP and temperature was studied in a batch system. An optimal condition for uptake C2NP was reached at pH≈ 5.8, 1 g of raw and modified bentonite in 60 and 10 min of equilibrium time, respectively. The results showed that increasing the initial concentration of 4C2NP, leading to a gradual increase in adsorption.

In this research, the efficacy of titanium dioxide nanoparticles in the presence of visible light and induced visible light for the removal of reactive blue 21 from aqueous solutions was investigated. The experiments were studied in a box with visible and fluorescent light bulbs, to study the effect of various parameters such as irradiatioin time, amount of catalyst, pH, initial concentration and temperature. The results showed that the performance of nano-TiO2/induced visible light system is better than nano-TiO2/visible light. Operational parameters showed that in nano-TiO2/induced visible light system at irradiation time of 10 min, the amount of 1 g of the catalyst and an alkaline media (pH =9) dye removal efficiency was over 40%. Also, the results showed that the removal efficiency decreased with increasing the dye concentration. Kinetic studies showed that the removal of reactive blue 21 by nano-TiO2/induced visible light system obeys zero-order model. In other words, the color removal rate is independent of concentration.

In this paper, activated α-Alumina have been used as sorbents for the removal of a cationic dye, malachite green from aqueous solutions. The process of removal has been optimized for different parameters like initial concentration of dye solution, contact time, pH, adsorbent dose, and temperature. Also, pHzpc of the adsorbent was determined. Results showed that equilibrium was achieved in 10 min and removal of malachite green increased by increasing of adsorbent dosage and pH. The experimental results indicate that 0.1g/250 mL g of activated α-Alumina was able to remove 55.05% of dye from an initial concentration of 5 mg L-1 at pH=10. The results show that actived α-alumina can be a better adsorbent for the removal of malachite green from aqueous solutions.