Full article
Separation Technology,
P. Abbasi; k. Shayesteh; v. vahidfard; M. Hosseini
Abstract
In an Iranian zinc smelter plant, nickel and cadmium are removed from the electrolyte solution at the cold purification stage with the help of zinc powder. This study tries to investigate the optimal conditions for the removal of these impurities through the response surface methodology by examining ...
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In an Iranian zinc smelter plant, nickel and cadmium are removed from the electrolyte solution at the cold purification stage with the help of zinc powder. This study tries to investigate the optimal conditions for the removal of these impurities through the response surface methodology by examining the effects of effective parameters on the process. The results of the experiments showed that cadmium was cemented by zinc powder much more conveniently than nickel. The interplay of parameters showed that increasing the concentration of zinc powder can reduce the time and temperature of the entire reaction. It also neutralized the effect of the changes of pH and mixing speed. The optimum conditions for the simultaneous removal of nickel and cadmium were obtained at 75 °C, the pH of 4.5, the residence time of 45 min, the mixing speed of 500 rpm, and 2 g/l of zinc powder. Under optimal conditions, more than 99 % of nickel and cadmium were removed from the electrolyte solution.
Full article
Polymer Engineering and Technology,
A. Mehralizadeh; F. derakhshanfard; Z. Ghazitabatabaei
Abstract
General Purpose Polystyrene (GPPS) has weak properties and this weakness made the applications of this polymer be limited. Therefore, the use of the mixtures of polymers can improve these properties. Different parameters like the mixing speed can affect the quality of the properties of preparing polymer ...
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General Purpose Polystyrene (GPPS) has weak properties and this weakness made the applications of this polymer be limited. Therefore, the use of the mixtures of polymers can improve these properties. Different parameters like the mixing speed can affect the quality of the properties of preparing polymer from the mixture of several polymers. In this research, the polymer blend of GPPS and Acrylonitrile-Butadiene Styrene (ABS) has been investigated. In order to prepare this polymer mixture, GPPS has been considered as the main phase (base polymer) and ABS has been considered as the scattered phase (additive). Firstly, the blended polymers with different weight percentages (0, 0.04, 0.08 and 0.12) of ABS/GPPS in different mixing speeds (30, 40, 50 and 60 rpm) have been prepared and for each mixture, the Melt Flow Index (C), Vicat Softening Temperature, Tensile at Break and impact test have been measured. The laboratory data collected from different tests, has been simulated by the Multi-Layer Perceptron (MLP) method of Artificial Neural Networks (ANN) and the results of the simulated data covered the laboratory data perfectly. The results declare that the presence of ABS in the mixed polymer improved the Tensile strength and thermal properties. In order to reach the highest quality in carried out tests, it is considered to use ABS in a high percentage (0.12) and the maximum possible mixing speed (60 rpm).
Full article
Process Control and Engineering, Process Safety, HSE
A. Bahramian
Abstract
In this study, the inactivation performance of units against pathogenic and biotoxin threats in a water treatment plant is studied. The assessment of the units and hazards of the water treatment plant against each of threats is studied by the RAMCAP risk analysis. The experiments showed that the Aflatoxin ...
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In this study, the inactivation performance of units against pathogenic and biotoxin threats in a water treatment plant is studied. The assessment of the units and hazards of the water treatment plant against each of threats is studied by the RAMCAP risk analysis. The experiments showed that the Aflatoxin was eliminated only by disinfection units. The reverse osmosis unit had high efficiency in removing Ricin, while the sand filtration had the lowest efficiency in removing biotoxins. The microbial analysis showed the total coliform bacteria, thermotolerant coliform and HPC index were increased slightly by increasing the incoming water's pH and turbidity, while their count were significantly reduced by increasing the free residual chlorine. Changes in the water temperature also had minor effects on microbial indexes. The RAMCAP analysis is used to reduce the vulnerability of units to conventional threats by determining
Full article
Materials synthesize and production
Y. Rabbani,; M. Shariaty-Niassar; S.A Seyyedebrahimi
Abstract
Many industries produce large volumes of effluent which are made of oil and its derivatives; very common pollutants in the environment. The use of hydrophobic magnetic particles due to their low cost, low toxicity, and availability is one of the preferred methods for separating oil from water in oil ...
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Many industries produce large volumes of effluent which are made of oil and its derivatives; very common pollutants in the environment. The use of hydrophobic magnetic particles due to their low cost, low toxicity, and availability is one of the preferred methods for separating oil from water in oil spillage issues. This research aims at evaluating the effects of dopamine as a link in the hydrophobicity of carbonyl iron (CI) particles with stearic acid. In this connection, CI @ stearic acid and CI @ dopamine @ stearic acid have been synthesized. The FESEM analysis was used to observe the surface modification and structure of the particles. The magnetic properties of hydrophobic particles were also measured and the magnetic saturation of CI, CI @ stearic acid, and CI @ dopamine @ stearic acid were 200, 169, 131 emu/g respectively. Finally, the contact angle and adsorption capacity of two modified particles were measured. Based on the result, the static contact angles of water drops placed on the beds of the CI, CI @ stearic acid, and CI @ dopamine @ stearic acid were found to be 0°, 162.9°, and 168.24° respectively. The adsorption capacity range for CI@ stearic acid particles was 1.5 to 2.2 and for CI@ dopamine@ stearic acid particles was 1.8 to 3.2. Therefore, the result showed that dopamine had a good effect as a link to the hydrophobicity of carbonyl iron particles.
Full article
Environmental Engineering,
A. Hemmati; M. Raeisi; M. borghei
Abstract
Many communities in the world use groundwater as a source of potable water. The high nitrate concentration is a serious problem in groundwater usage. This study utilizes a biological denitrification method to investigate a moving bed biofilm reactor (MBBR) for the case of Tehran's groundwater. One pilot-scale ...
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Many communities in the world use groundwater as a source of potable water. The high nitrate concentration is a serious problem in groundwater usage. This study utilizes a biological denitrification method to investigate a moving bed biofilm reactor (MBBR) for the case of Tehran's groundwater. One pilot-scale MBBR with a 3 liter volume was designed and used in this research. The denitrification reactor operates under anoxic conditions. Methanol was used as a carbon source in the reactor throughout the study, and fifty percent of the reactor volume was occupied with KMT packing (k1). To determine the optimum nitrate loading rate, the concentration of nitrate changed from 100 to 400 mg N/l. It was concluded that heterotrophic denitrifying bacteria converted nitrate to nitrogen. According to obtained results, the removal efficiency and optimum loading rate were estimated during the experiments in different concentrations and different HRTs for this type of reactor. Sodium nitrate was in the feed source in the anoxic reactor. The maximum removal rate of nitrate was measured to be 2.8 g of NO3-N m-2 carrier d-1. Therefore, it was shown that the optimum loading rate of nitrate and the optimum COD/N were equal to 3.2 g of NO3-N m-2 carrier d-1 and 6 g of COD/g N respectively.
Short Paper
Materials synthesize and production
K. Ashitosh; Manjunath S P; B. Prakash
Abstract
In this work, the phosphate bonded refractory was developed using magnesium potassium phosphate cement. The Cement was prepared from the caustic calcined magnesium oxide with the addition of mono potassium phosphate. The characterization of the cement was done by XRD and SEM to examine the change in ...
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In this work, the phosphate bonded refractory was developed using magnesium potassium phosphate cement. The Cement was prepared from the caustic calcined magnesium oxide with the addition of mono potassium phosphate. The characterization of the cement was done by XRD and SEM to examine the change in phase and morphology which occurs after the hydration of magnesium potassium phosphate cement which is in the struvite phase. To evaluate the physical, mechanical and thermal properties, refractory samples were casted and subsequently dried and fired at temperatures ranged from 1300 °C to 1500 °C. The effect of temperature on the bulk density, apparent porosity and crushing strength were analyzed. It was found that the properties of the chemically bonded refractory were better than the conventionally bonded calcium alumina cement refractory.