10 research outputs found
Cadmium removal from aqueous solution by green synthesis iron oxide nanoparticles with tangerine peel extract
Study of Co(II) adsorption from aqueous solution using protein granules produced from chicken feather
Background: Co(II) constitutes a part of vitamin B12, hence, it is necessary for human health. However, at concentrations higher than the permissible limits, humans and animals suffer adverse chronic effects. It is necessary to reduce the concentration to a permissible level. In the present study, pre-purification and thermal modification of chicken’s feather increased their porosity and they were used to adsorb Co(II) ions from aqueous solutions.
Methods: Chicken feather was procured from a slaughter house, washed with detergent and dried at laboratory temperature. To increase the porosity and remove the organic pollutants attached to the feather, feathers were heated in the oven for 1 hour at 165°C. Some batch experiments were conducted to optimize the parameters affecting the adsorption process, such as solution pH, initial concentration of Co(II) and contact time, at a constant agitating speed and temperature.
Results: The pHzpc of chicken’s feather granules obtained was 5.3. The results showed that a time of 60 minutes, pH value of 9 and initial concentration of 10 mg/l were the optimum conditions for Co(II) removal by the adsorption process. Increasing the initial concentration of Co(II) from 10 to 50 decreased the removal efficiency from 52% to 26%. The pseudo-first order kinetic model provided the best correlation (R2 = 0.998) for adsorption of Co(II) on chicken’s feather granules.
Conclusion: The increase in electrostatic repulsion forces between positive charges of Co(II) ions decreased the removal efficiency at higher concentrations of Co(II) ions. The maximum efficiency of Co(II) adsorption was obtained at pH= 9, which is higher than the pHzpc of the adsorbent.
Keywords: Adsorption, Chicken feather, Co(II), Protein
Investigating the Concentration of Heavy Metals in Bottled Water and Comparing with its Standard: Case Study
Introduction: Today, bottled waters have attracted the assurance of consumers as one of the important drinking water supply resources, such that in some regions, the use of bottled waters has replaced the drinking water distribution system. The present study was carried out with the aim of measuring and determining the heavy metals in bottled water across a number of brands produced in Iran and comparing it with the drinking water standard.
Materials and Methods: In this descriptive-cross-sectional study, two different brands of bottled water were randomly sampled from the supermarket. To measure the heavy metals of interest, the samples were concentrated and then the concentration of some heavy metals such as copper, zinc, nickel, iron, aluminum, lead, and cadmium ions were measured by atomic absorption spectrophotometer. The mean concentration of ions was calculated in each brand and then compared with amount of standards.
Results: Brand No. 1, the concentration of zinc ion was larger in Brand 2 while in Brand No. 2 had larger copper, nickel, and aluminum ions. The results indicated that the concentration of the measured metal ions were below the allowable limit of drinking water standard across all of the studied samples.
Conclusion: Based on the obtained results from the investigated parameters, it can be concluded that the bottled water of both brands poses no health issue and is drinkable. Considering the changes in the concentration of ions and the increasing trend of consumption of bottled waters, their monitoring and qualitative control of pollutants are very crucial in terms of public health
Copper and Nickel Determination in Grape Extract Cultured around Marvast City,Yazd
Background: One of the most critical problems in the field of water and food pollution is the heavy metal pollution. Agricultural products are exposed to this type of contamination through wastewater; industrial activity and population pollutions are also in its area. Since the plant in the affected areas can directly enter heavy metals into the food chain, so, it is important to check their level of contamination. The purpose of this study was to monitor distribution of copper and nickel in the grape cultured in the farms around Marvast in Yazd province. Methods: All chemicals were of analytical grade. In order to determine the level of copper and nickel in grape extracts produced from the most important areas in grape production, 7 samples of grape were taken from these geographic regions. After grinding and homogenizing of samples, the concentration of nickel and copper, heavy metals were measured by atomic absorption spectrometer. The obtained results were analyzed through SPSS software based on statistical methods. Results: The mean value of copper and nickel were 26.4 ± 3.1 and 12.3 ± 1.5 μg/kg, respectively. According to the obtained results and their comparison with standards, different amounts of copper and nickel were observed in all samples, however, the highest amount of these metals was observed in one sample. Conclusions: Concentrations of heavy metals in samples from different regions were lower than the maximum allowable concentration of copper and nickel. Although, the amount of these metals in one sample, known as pollution indicator, suggested that this area can be exposed to both
Knowledge, attitude and performance of wood painter about harmful effects of solvents and dyes on human health
Background: Solvents, which are widely used in industry, are able to dissolve another substance for creating a solution. Solvents have various effects on human health based on their type and chemical composition.
Methods: This was a cross-sectional study to investigate the harmful effects of solvents on wood painters in Yazd city. To achieve information, a census questionnaire was prepared and distributed among wood painters. The studied parameters include the mean score of knowledge, attitude, and practice of wood painters about harmful effects of dyes and solvents on body according to age, work experience, education, hours worked per day, and smoking. The data of survey were analyzed by Chi-square test and T-test in SPSS.
Results: The average age and work experience of wood painters were 29 and 7.5 years, and the age of 25 years and work experience of 5 years had the highest frequency among them. Analysis of data indicated that 71.8% of people had middle school and lower education level, 68.3% was married, 31.7% was single, and 37.5% was smoking. Average working hours were 8 hours in day.
Conclusion: Results show that attitudes had significant correlation with education level and different age groups. None of the studied parameters were not significant correlation with performance. Also, there was significant correlation between knowledge with experience
Bisacodyl removal from contaminated solution by synthesized mesoporous silica using experimental design method
Abstract Most of the medicinal compounds are entered no change into municipal wastewater and more than 90% of it remains in the wastewater. Mesoporous silica is known as thermally stable materials with controllable porosity and morphology. It is specified that these materials possess external and internal surfaces that can be selectively adsorbed the various compounds. In the present study, the synthesized mesoporous silica was studied to remove bisacodyl from polluted solutions. Mesoporous silica was synthesized by simple chemical method from tetraethylorthosilicate, ethanol (C2H5OH) and deionized water at 70 °C temperature. Characteristic of synthesized mesoporous silica was investigated by scanning electron microscopy. The effective parameters such as contact time, pH, adsorbate dose, and initial bisacodyl concentration were optimized for bisacodyl removal using 27 batch adsorption experiments according to design of experiment. The residual bisacodyl concentration was measured by UV–Vis spectrometer at the maximum wavelength of 580 nm. The statistical test and linear regression model were used by MINITAB 16 software for investigation of the main and interaction effects of each factor in the adsorption process. The ANOVA result showed 84% of bisacodyl was removed by synthesized mesoporous silica at optimum condition. The result of regression (R2 > 0.99) indicated that the adsorption process followed the Langmuir isotherm and second order kinetic at optimum conditions. The mesoporous silica is an efficient adsorbent for removing of bisacodyl from the polluted solutions so that it can be used for refining wastewaters containing medical compounds such as bisacodyl
Modification of pomegranate waste with iron ions a green composite for removal of Pb from aqueous solution: equilibrium, thermodynamic and kinetic studies
Abstract Pomegranate waste modified with Fe2+ and Fe3+ ions followed with carbonization were used as an adsorbent to remove the Pb2+ ions from aqueous solution. To optimum the highest adsorption efficiency, adsorption experiments were conducted on iron modified carbons by batch technique. The characteristic of composite was studied by scanning electron microscope (SEM) and Fourier transform infrared spectrometer (FT-IR). The best pH for control of chemical adsorption was selected within pH of 6.0–6.5. It was observed that the contact time of 90 min, initial concentration 50.0 ppm, and adsorbent dose, 1.0 g/100 ml solution was found to be optimum conditions. On this condition, the maximum adsorption capacity was obtained 27.5 and 22.5 mg/g for Fe2+ and Fe3+ impregnated pomegranate peel carbons (PPC), respectively. The value of Cid, 1.584 for Fe2+-PPC and 0.552 for Fe3+-PPC, indicates that the effect of the boundary layer is more important in adsorption of Pb2+ by Fe2+-PPC and the pore diffusion is the rate limiting mechanism after 30 min. Thermodynamic parameters of Gibbs free energy, enthalpy, and entropy of Pb2+ adsorption on iron-modified carbons suggest that the adsorption process is favorable and spontaneous under the optimum condition
Application of magnetic iron oxide nanoparticles in stabilization process of biological molecules
Introduction: Because of their unique properties, magnetic nanoparticles have attracted the attention of many researchers in various fields. The stabilization enzyme on functionalized magnetic nanoparticles, with the maintenance of free protein activity and optimal stability, have been developed by various surface modification techniques. This review focused on the methods for modification of iron magnetic nanoparticles and their application to stabilize protein.
Methods: Among the published valid articles, 51 articles were selected from various scientific databases between the (2000-2016) years. The papers were evaluated for biological, physical and chemical synthesis methods, advantages and limitations of synthesis methods, application of surface modification and enzyme fixation on iron oxide nanoparticles. Precisely analyzing of papers, the most suitable method was investigated for the synthesis of nanoparticles and the use of nanoparticles was summarized in the biomolecules fixation process.
Conclusion: Co-precipitation method is an easy way to prepare magnetic nanoparticles of iron with a large surface and small particle size, which increases the ability of these particles to act as a suitable carrier for enzyme stabilization. Adequate modification of the surface of these nanoparticles enhances their ability to bind to biological molecules. The immobilized protein or enzyme on magnetic nanoparticles are more stable against structural changes, temperature and pH in comparison with un-stabilized structures, and it is widely used in various sciences, including protein isolation and purification, pharmaceutical science, and food analysis. Stabilization based on the covalent bonds and physical absorption is nonspecific, which greatly limits their functionality. The process of stabilization through bio-mediums provide a new method to overcome the selectivity problem
Study of Co(II) adsorption from aqueous solution using protein granules produced from chicken feather
Background: Co(II) constitutes a part of vitamin B12, hence, it is necessary for human health. However, at concentrations higher than the permissible limits, humans and animals suffer adverse chronic effects. It is necessary to reduce the concentration to a permissible level. In the present study, pre-purification and thermal modification of chicken’s feather increased their porosity and they were used to adsorb Co(II) ions from aqueous solutions.
Methods: Chicken feather was procured from a slaughter house, washed with detergent and dried at laboratory temperature. To increase the porosity and remove the organic pollutants attached to the feather, feathers were heated in the oven for 1 hour at 165°C. Some batch experiments were conducted to optimize the parameters affecting the adsorption process, such as solution pH, initial concentration of Co(II) and contact time, at a constant agitating speed and temperature.
Results: The pHzpc of chicken’s feather granules obtained was 5.3. The results showed that a time of 60 minutes, pH value of 9 and initial concentration of 10 mg/l were the optimum conditions for Co(II) removal by the adsorption process. Increasing the initial concentration of Co(II) from 10 to 50 decreased the removal efficiency from 52% to 26%. The pseudo-first order kinetic model provided the best correlation (R2 = 0.998) for adsorption of Co(II) on chicken’s feather granules.
Conclusion: The increase in electrostatic repulsion forces between positive charges of Co(II) ions decreased the removal efficiency at higher concentrations of Co(II) ions. The maximum efficiency of Co(II) adsorption was obtained at pH= 9, which is higher than the pHzpc of the adsorbent
Monitoring of Zinc level in Milk of Breastfeeding Mothers at First Month of Delivery
Introduction: Zinc plays a vital role in various biological functions and physical growth. More than 300 enzymes in body need zinc for proper function. In this study, the concentration of the zinc micronutrient in breast milk was evaluated and analyzed at the first month of breastfeeding.
Materials and Methods: This was a descriptive study of 150 breastfeeding mothers in the 2014 who had given birth in Yazd and were sampled in a simple way. Sampling was done exclusively in the health and treatment centers in the city, in the spring of 2014. 10- 20 ml samples of breast milk were taken manually in the morning and before infants' feeding, in 3 times of 5, 15 and 30 days after delivery, to measure the micronutrient of zinc. The concentration of zinc was measured by atomic absorption spectroscopy.Data obtained by questionnaires and atomic absorption was analyzed by ANOVA test.
Results: The average age of mothers was 27.40 ± 4.67 years. The average level of zinc in breast milk was 2.60 ± 0.35 mg/l. The zinc concentration of breast milk was at the bottom of the standard range of zinc in breast milk.There was no significant relationship between zinc averages in milk with education, age, BMI and mothers' job. But, there was a direct relationship between zinc levels of breast milk with mothers' BMI.
Conclusion: According to the results of this study, it seems that addition of zinc to the diet of breastfeeding mothers helps to prevent zinc deficiency in mothers' blood serum as well as children's nutrition