8 research outputs found
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 30â—¦C and 40â—¦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 40â—¦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