Fabrication of UV/ TiO2 nanotubes / Pd system by electrochemical anodization for furfural photocatalytic degradation

The aim of this study was to degrade furfural by a new nanotube system. To degrade some organic pollutants as well as to reduce the amount of furfural which is a well-known pollutant in oil industry, the photocatalytic process along with ultraviolet (UV) irradiation may be employed. In this study, the UV/TiO2/Pd system in which the nanoparticles of palladium doped into the titanium dioxide was proposed for degradation of furfural. The rate of furfural decomposition in the proposed system was more than that of the system without TiO2 foils due to the degradable reactions. The experimental results demonstrate that the maximum degradation occurs at a distinct pH and specific temperature under the UV irradiation. After 100-minute UV-irradiation duration, the maximum and minimum degradations were 97.8% (pH 3), and 95.8% (pH 12), respectively. Also, the degradation values were as parabolic function at the pH values. The values of efficiency of decomposition for this irradiation duration at optimum pH 3 were 96.7% and 98.5% at 30◦C and 40◦C, respectively. Also, the minimum degradation under photolysis was 93.52% at 30oC under 20-minute UV-irradiation duration. Furthermore, while the irradiation duration was 70-75 min, the degradation values were independent of pH approximately. The difference between the degradation values at 30 and 40◦C was decreased with increasing the UV-irradiation duration till 60min, and then this difference was increased with increasing the UV-irradiation duration

Optimization Conditions For Determination of Cosmetic Preservatives using Ion-Exclusion Chromatography

An ion chromatography (IC) method for simultaneous determination of benzoic, salicylic and sorbic acids was developed. In this method the samples were purified by solid-phase extraction. The analytes were then eluted with methanol from C18 cartridge. The separation was performed on ion-exclusion column by an isocratic elution with 0.25 mmol /L sulfuric acid solution containing 20% (v/v) acetone as elute. The calibration curves showed good linearity with suppressed conductivity detection. Under this condition, separation of the three components was achieved in less than 23 min. The detection limit calculated as the concentration corresponding to three times the background noise, was 0.1, 0.15 and 0.2 mg/ L for benzoic acid, salicylic acid and sorbic acid respectively. The method was successfully applied to analysis of various cosmetic products

A New Potentiometric Sensor for Determination of Cesium ion in Environmental samples

ABSTRACT: A new cesium ion selective PVC membrane based on parent calix [4] arene was developed for potentiometric determination of cesium in environmental samples. The electrode based on p-5,11,17,23tetra(tertbutyl)25,26,27,28-tetrahydroxy calix[4]arene(THC) as ionophor ,dibutyl phthalate (DBP)as plasticizer ,sodium tetra phenyl borate(NaTPB)and oleic acid as lipophilic salt and additive showed the best performance. The M.It exhibits a good selectivity for cesium in comparison with alkali, alkaline earth, and some transition metal ions. The electrode response and selectivity remained almost unchanged for more than a month. The effect of membrane composition, pH and concentration of internal solution on the potential response of the electrode were also studied. The applicability of the electrode to real samples was also assessed. Key words: Potentiometric determination, Cesium ion-selective electrode, Environmental samples INTRODUCTION Lots of studies have discussed different aspects of water bodies pollution with different kinds of metal

Reduction of environmental pollution through optimization of energy use in cement industries

Industrial development has lead to higher energy consumption, emission of greenhouse gases, as well as air pollutants. Cement factories play an important role in over all greenhouse emissions. This study aims to investigate the role of Iranian cement industries and their contribution of greenhouse gases contribution. The measured emission factors for oil and fuel gas shows that carbon dioxide contribution from fuel oil based cement industries is almost 2.7 times higher than gas based cement factories. The strength, weakness, opportunity and threat technique analysis showed that the best strategy to combat greenhouse gases from Iranian cement factory is to implement energy efficiency measures. Further, strategic position and action evaluation matrix analysis indicates that Iranian cement industries fall within invasive category. Therefore, exploitation of opportunities must carefully be used. One of these opportunities is the utilization of financial assistance provided by clean development mechanism. The results show that replacement of ball mills with vertical roller mill can reduce the electricity consumption from 44.6 to 28 kWh/ton. As a result of such substitution about 720 million kWh/y of electricity would be saved (almost a power plant of 125 MW capacities). Though implementation of new mills may not be economic for the cement industries’ owner, but the overall gain for the government of Iran will be about US$ 304 million. If the duration of such efficiency measure is considered as about 12 y, then the overall CO2 reduction/phase-out would be around 4.3 million tons

The Pre-concentration and determination of Iridium and Palladium in environmental water by imprinted polymer-based method

In this study, the imprinted aniline-formaldehyde was used as an adsorbent for removal of Iridium and Palladium ions from aqueous solutions through batch equilibrium. The sorbent was characterized by fourier transform infrared spectroscopy. The influence of pH, equilibrium time, temperature and initial concentration of metal ions on adsorbed amount of both ions were investigated. The maximum adsorption capacity in initial concentration of 100 mg/L was found to be 12.5 mg/g at pH 7.0 and 14.3 mg/g at pH 8.0 for Iridium and Palladium, respectively. In addition, the best desorption of the metal ions from resin was obtained by 0.5 mol/L nitric acid as eluting agent. The profile of both ions uptake on this sorbent reflects good accessibility of the chelating sites in the imprinted aniline-formaldehyde. Langmuir, Freundlich, Temkin and Redlich-Peterson isotherm models were applied to analyze the experimental data. Moreover, Langmuir linear method was used to obtain the isotherm parameters. However, Langmuir type II achieved the highest coefficient which led to the best fit for the palladium and the best fit for Iridium obtained from linear Redlich-Peterson. However, the thermodynamic parameters (ΔG°, ΔH°, and ΔS°) were also determined using the equilibrium constant values obtained at different temperatures. The results showed that the adsorption for Iridium and Palladium ions was spontaneous nature and endothermic. Moreover, the method was applied for the determination of both ions from tap water samples

New chelating resin for preconcentration and determination of molybdenum by inductive couple plasma atomic emission spectroscopy

A chelating resin is prepared by condensation polymerization of aniline with formaldehyde and characterized by Fourier transform infrared spectrometer, elemental analysis and thermogravimetric analysis and studied for the preconcentration and determination of trace Molybdate ion from environmental water sample using inductive couple plasma atomic emission spectroscopy. The optimum pH value for sorption of the metal ion was 5. The sorption capacity of functionalized resin is 3.1 mg/g. The chelating sorbent can be reused for 20 cycles of sorption-desorption without any significant change in sorption capacity. The best desorption of the metal ions from resin was obtained by 0.5 mol/L nitric acid as eluting agent. The profile of molybdenum uptake on this sorbent reflects good accessibility of the chelating sites in the aniline- formaldehyde. Scatchard analysis revealed that the homogeneous binding sites were formed in the polymers. The equilibrium adsorption data of Molybdate ion modified resin were analyzed by five isotherm models such as Langmuir, Freundlich and Temkin. Langmuir isotherm parameters obtained from the four Langmuir linear equations by using linear method. Based on the Langmuir isotherm analysis, the monolayer adsorption capacity was determined to be 4.03 mg/g at 20 °C. The method was applied for molybdenum ions determination from river water sample