Background and Objective: Textile wastewaters are known as an important environmental pollutant. The main characteristic of textile wastewater is its colorness, which contains various organic and inorganic pollutants. Therefore it is necessary to treat such effluent effectively before discharging into the environment.Methods: In a fundamental-applicable study, removal efficiency of Acid red 18 and Acid red 14 using zero valent iron powder has been investigated. Parameters studied include pH (3-11), contact time (15-120 min), and initial concentration of iron powder (0.5-2 g/L).Results: Batch experiments show that dye removal was increased with increasing mass of iron powder and contact time, while decreased with increasing of pH. The high removal efficiency was observed in pH=3, contact time=120 min and iron powder concentration of 2 g/L. The result of kinetic studies shows that removal of Acid red 18 and Acid red 14 was best described by pseudo-second order kinetic model.Conclusion: the overall results of present work shows efficient removal of Acid red 18 and acid 14 by zero valent iron powder.

Wastewater from the textile industry, especially that containing azo compounds, often contains toxic materials that persist in the environment. Therefore, it is necessary to evaluate the performance of various methods for their removal. Acid red 37 combinations represent a single structure in the azo dyes which have already been widely used in the textile industry. The purpose this study is the optimization of effective factors and investigation performance of the electrofenton and electrocoagulation methods in synthetic wastewater for Acid Red 37 dye removal from aqueous solutions. In this study, synthetic wastewater was formed from Acid Red 37 dye and pilot Scale and the concentration, pH, electrical density and temperature parameters were investigated. Ultimately the optimum conditions were determined as well as the amount of energy consumption at 90 percent efficiency. To investigate the pollutant degradation GC-Mass was used and the results show that both methods had the ability to remove Acid Red 37. Electrocoagulation was found to be more efficient than the electrofenton method; respectively, the optimum conditions for removal by the electrofenton and electrocoagulation methods were pH=3, time=120 min, density- 30 mA.cm2, concentration=50 mg/L, consumption energy 142.8 KWh/Kg Dye and pH=7 time=120 min, density- 30 mA.cm2, concentration=150 mg/L, consumption energy 130.2 KWh/Kg Dye. These results show that the electrocoagulation method was better than electrofenton with its high ability for removal Acid Red 37.

Introduction: In order to improve caries detection, invasive methods should not be used and caries detector is useful, and antibacterial solutions can be used as well as a biological method for caries detection. Aim of the present study was to differentiate sound dentin from infectious dentin by two coloring solutions: acid red and povidone iodine.Methods: In this experimental investigation, 140 carious molar teeth were collected. Teeth were kept in normal saline solution in room temperature and were divided into two groups, A and B (70 samples in each group). Teeth in group A were painted by acid red 1% solution and in group B by povidone iodine 10% and the painted points were recorded. After omission of the painted points, all samples of group A were painted by povidone iodine (group C) and all samples of group B by acid red (group D) and the painted points were recorded again. Data was analyzed using chi-square and Mc-Nemar tests.Results: Diagnostic accuracy of acid red for detection of dental caries was more than povidone iodine and the difference was statistically significant (P<0.05).Conclusion: It was concluded that the coloring power and accuracy of acid red is more than povidone iodine.

Doping of TiO2 nanoparticles have been accomplished by Au with 2% wt and using chemical reduction method. Their Photocatalytic efficiencies were evaluated by studying photo degradation of Acid Red 88 as a model contaminant from textile industries in aqueous solutions in the presence of visible light. In these work, Titanium tetra isopropoxide has been used as an organic source. Chemical reduction of Au particles has been done by using NaBH4. Furthermore, synthesizing of nanoparticles in different calcination temperatures (400, 450, 500, 550, 600oC) have been accomplished for achieving the best calcination temperature. The synthesized photocatalysts have been investigated by using various techniques such as X-ray and TEM. However; all of the doped photocatalysts have shown a remarkable photo degradation efficiencies (approximately increase 8% and 25% dye degradation in the presence of UV and Visible irradiation) compared to synthesized TiO2 in the presence of both UV and visible light sources.

Background & Objectives: Textile wastewater is known as environmental pollutant. The main characteristic of textile wastewater is presence of non-used color and various organic or inorganic pollutants. Therefore it is necessary to be treated before discharging to the environment using effective methods.Methods: Pumice was obtained from Tikmeh Dash Region of East Azerbaijan and was treated by HCL for improvement of its adsorption capacity before using as an adsorbent. The morphology of the medium used was investigated by XRF and SEM technology. Removal of Acid Red 14 and Acid Red 18 was investigated as a function of initial dye solution and contact time. In addition, equilibrium data was fitted onto Langmuir and Freundlich isotherm model. Furthermore, experimental data was fitted onto three kinetic models.Results: Removal of both dyes was increased by increasing of contact time and initial dye solution. The results of linear regression analysis show that removal of Acid Red 14 and Acid Red 18 follow the Freundlich (r2>0.99) and Langmuir (r2>0.99) model, respectively. Adsorption capacity was 29.7 and 3.125 mg/g for Acid Red 18 and Acid Red 14, respectively. The fitting of experimental data onto kinetic models shows the best fitting of obtained data onto pseudo-second order for Acid Red 14 and Acid Red 18.Conclusion: The result of present work shows that the effective removal of two azo dyes occurs in pumice stone modified by HCL.

Background: Organic dyes, with a complex structure, often toxic, carcinogenic, mutagenic, non-biodegradation and stable in the environment are and if without treatment enter the environment can endanger the environment and human health. The aim of this study was to nanoparticles zero valent iron synthesis and evaluate the performance of H2O2 and H2O2/Fe0 for the removal of dye Acid Red 18 from aqueous environments.Materials and Methods: This study was conducted at the laboratory scale. Nanoparticles were synthesized by reduction of ferric chloride using sodium borohydride and then removal efficiency of Acid Red 18 from a synthetic solution by H2O2 and H2O2/Fe0 was investigated. As well as effect of solution pH, dye concentration, concentration of nano zero valent iron, H2O2 and time contact in decolorization efficiency was investigated.Results: Results show that in the pH=3, contact time of 80 minutes, dye concentration of 75 mg/L and Concentration of nano zero valent iron, 2 g/L and H2O2, 200Mmol, about 90% day removal was observed.Conclusions: According to the results of experiments, the use to be of H2O2/Fe0 the efficiency in dye removal of Acid Red 18.