Optimization of photochemical decomposition acetamiprid pesticide from aqueous solutions and effluent toxicity assessment by Pseudomonas aeruginosa BCRC using response surface methodology

Contamination of water resources by acetamiprid pesticide is considered one of the main environmental problems. The aim of this study was the optimization of acetamiprid removal from aqueous solutions by TiO2/Fe3O4/SiO2 nanocomposite using the response surface methodology (RSM) with toxicity assessment by Pseudomonas aeruginosa BCRC. To obtain the optimum condition for acetamiprid degradation using RSM and central composite design (CCD). The magnetic TiO2/Fe3O4/SiO2 nanocomposite was synthesized using co-precipitation and sol�gel methods. The surface morphology of the nanocomposite and magnetic properties of the as-synthesized Fe3O4 nanoparticles were characterised by scanning electron microscope and vibrating sample magnetometer, respectively. In this study, toxicity assessment tests have been carried out by determining the activity of dehydrogenase enzyme reducing Resazurin (RR) and colony forming unit (CFU) methods. According to CCD, quadratic optimal model with R2 = 0.99 was used. By analysis of variance, the most effective values of each factor were determined in each experiment. According to the results, the most optimal conditions for removal efficiency of acetamiprid (pH = 7.5, contact time = 65 min, and dose of nanoparticle 550 mg/L) was obtained at 76.55. Effect concentration (EC50) for RR and CFU test were 1.950 and 2.050 mg/L, respectively. Based on the results obtained from the model, predicted response values showed high congruence with actual response values. And, the model was suitable for the experiment�s design conditions. © 2017, The Author(s)

Optimization of photochemical decomposition acetamiprid pesticide from aqueous solutions and effluent toxicity assessment by Pseudomonas aeruginosa BCRC using response surface methodology

Contamination of water resources by acetamiprid pesticide is considered one of the main environmental problems. The aim of this study was the optimization of acetamiprid removal from aqueous solutions by TiO2/Fe3O4/SiO2 nanocomposite using the response surface methodology (RSM) with toxicity assessment by Pseudomonas aeruginosa BCRC. To obtain the optimum condition for acetamiprid degradation using RSM and central composite design (CCD). The magnetic TiO2/Fe3O4/SiO2 nanocomposite was synthesized using co-precipitation and sol�gel methods. The surface morphology of the nanocomposite and magnetic properties of the as-synthesized Fe3O4 nanoparticles were characterised by scanning electron microscope and vibrating sample magnetometer, respectively. In this study, toxicity assessment tests have been carried out by determining the activity of dehydrogenase enzyme reducing Resazurin (RR) and colony forming unit (CFU) methods. According to CCD, quadratic optimal model with R2 = 0.99 was used. By analysis of variance, the most effective values of each factor were determined in each experiment. According to the results, the most optimal conditions for removal efficiency of acetamiprid (pH = 7.5, contact time = 65 min, and dose of nanoparticle 550 mg/L) was obtained at 76.55. Effect concentration (EC50) for RR and CFU test were 1.950 and 2.050 mg/L, respectively. Based on the results obtained from the model, predicted response values showed high congruence with actual response values. And, the model was suitable for the experiment�s design conditions. © 2017, The Author(s)

Evaluation of synthesized iron oxide nanoparticles in removal of copper ions from aqueous solution

Abstract Introduction: water source pollutant, result of direct releasing of metal ions to environment, is one of the most important problems in the world. In this study, efficiency of synthesized iron oxide nanoparticles in presence of extract tangerine Peel was investigated for removal of copper ions in the solution. Methods: Iron oxide nanoparticles were prepared by co-perception method using Tangerine Peel extract. The Tangerine Peel extract used to decrease of nanoparticle size and to prevent of particles coagulation. The effect of different parameter includes initial copper concentration, adsorbent dose, contact time and solution pH was investigated on removal of copper. The experimental data were fitted to Langmuir and Freundlich isotherm models. Results: The results showed that the removal efficiency was increased by increasing of pH and decreased from 88% to 81% by increasing of initial copper concentration from 5 mg/l to 10 mg/l. The most removal percent was 92% when copper concentration was 5 mg/l and adsorbent doze was 0.6 g in 100 ml suspension. Conclusion: The results showed the removal efficiency is depended on to pH. The increase of copper concentration decreased the removal efficiency. Adsorption experimental data were in good accordance with Langmuir isotherm model. The synthesized iron oxide nanoparticles with extract Tangerine Peel is a good adsorbent for removing of heavy metals from aqueous solution

Preventive Behavior of Recurrent Kidney Stones and Its Relationship with its Knowledge and Receiving it

Introducatn: Kidney stone is the most common chronic kidney condition after hypertension. kidney stone recurrence is common worldwide and it is estimated that almost 50% of stone formers will have a recurrence within 10 years. Patients' knowledge on kidney stones and its recurrence prevention is an important factor in preventive behaviors of kidney stone recurrence. This study aimed to determinine the preventive behaviors of kidney stone recurrence on it and its relation to knowledge on it and also knowledge on it receiving resources. Methods: This descriptive- analytical study was performed as cross-sectional. The sample size consisted of 210 persons who had referred to 3 care centers in Yazd. Data Collection instrument was a questionnaire that had two parts: the first part was demographic information and the second part was scales for preventive behavior of kidney stones recurrence, knowledge aassessment and cues to action which were completed with interview. Data were analyzed with T-test, ANOVA, χ2 and correlation coefficient test thnough spss 16. Results: Mean score of recurrence preventive behaviors was 38.75 ± 7.85 from 70 the Mean score on knowledge was 9.49±7.85 from 25 and Mean score of cues to action was 2.67±1.78 from 8. The lowest reported recurrence preventive behavior was consulting with a registered dietitian or specialist about consumption of fruits and vegetables. The lowest reported knowledge was about dairy consumption in individuals with a history of kidney stone (21.4%), and the highest reported cues to action was other kidney stone patients (54.3%). Pearson correlation showed a positive correlation between preventive behaviors, knowledge and cues to action (P<0.05). Conclusion: Regarding the low rate of knowledge and performance of the subjects as well as the high age of patients suffering from kidney stones and lack of enough education in this group, health staff can be the most important source of knowledge for these people about preventive behaviors of kidney stones recurrence

The Evaluation of Removal Efficiency of COD Due to Water Contaminated by Gasoline by Granular Active Carbon

Abstract Introduction: Oil pollution has severe effects on the water resources, environment, soil and human health. One of the most important goals of environmental engineers is removing of contaminants from water. Adsorption process is an effective manner for removing of contaminants in aqueous solutions. In this study, the efficiency of adsorption process by activated carbon granular has been investigated to decrease chemical oxygen demand (COD) due to gasoline in water. Methods: This study was an experimental study that was conducted in laboratory scale. The adsorption process was done batch in 100 ml in closed Erlenmeyer and the effective parameters such as the initial concentration of contaminant (1, 2% V/V) and contact time (2, 5, 10, 20, 30 and 60 min) were adapted. In all experiments, pH of 7.85 and the adsorbent mass of 1g/100mL were fixed. The COD values were measured by return reflux method according to D 5220 method presented in Standard Methods book for water and wastewater examinations. Data were analyzed with Freundlich, Langmuir and Temkin isotherm models for determining of adsorption isotherm. The charts were drawn by Excel software. Results: The results of this study showed that the average of gasoline removal percent in 1 and 2% was 93.64±3.17 and 53.7 ± 22.76, respectively that the difference was significant (P-value0.05). Regression coefficients showed that adsorption data followed by Freundlich isotherm model and pseudo-second order kinetic. Conclusion: We can conclude from this study that the activated carbon is an appropriate adsorbent for decreasing of COD due to gasoline contamination in water. The use of this adsorbent can well decrease COD of water contamination due to gasoline at times of 30 min

The Investigation of Electron Beam Catalytical Oxidation Process Efficiency with Potassium Persulfate in Removal Humic Acid from Aqueous Solutions

Introduction: The most important affect of natural organic matters in water is their reaction with chlorine and producing of disinfection byproducts that are carcinogenic. Humic acid is most common natural organic materials of surface water. Advanced oxidation processes (AOPs) are methods for the removal of organics from aqueous solutions. Application of electron beam radiation is one of these methods for water treatment. The aim of this study was to evaluate the efficiency of catalytic oxidation process of electron beam radiation with potassium persulfate in removal of humic acid from aqueous solutions. Methods: This experimental study was performed in laboratory scale. In this study, effect of pH (4 -10), initial concentration of potassium persulfate (0.1- 0.5 mmol/100cc), different radiation doses of electron beam (1-15 kGy) and the initial concentration of Humic acid (10-50 mg/l) in removal of humic acid were studied. Electron irradiation performed using an electron accelerator model TT200. Residual concentrations of humic acid in the samples determined by spectrophotometer UV/Vis at a wavelength of 254 nm. Results: Based on the results, changes in pH had little effect on the Humic acid removal efficiency. The average, with increasing of pH from 4 to 10, the removal efficiency of humic acid from 72.59% to 73.36% increased, respectively. The results showed that increasing of the dose from 1 to 15 kGy, humic acid removal efficiency increases. Based on results by increasing of persulfate concentration, the removal efficiency increased so that with increasing of concentration of potassium persulfate from 0.1 to 0.5 mmol/100cc, removal efficiency from 69.43% to 83.82% was increased. Kinetic experiments showed that the decomposition of humic acid by electron beam radiation followed the second-order kinetic. Conclusion: The data from this study showed that the aqueous solution containing acid Humic is decomposed effectively by electron beams irradiation. Addition of potassium persulfate can be have significant improvements in removal efficiency of humic acid in the presence of electron beam

Optimizing the photocatalytic process of removing diazinon pesticide from aqueous solutions and effluent toxicity assessment via a response surface methodology approach

Diazinon is one of the most dangerous environment pollutants. In this study, the optimization of removing diazinon from contaminated aqueous solutions was evaluated by advanced oxidation process along with the evaluation of effluent toxicity by Escherichia coli bacteria. The design of the experiments was based on the response surface methodology. Iron oxide nanoparticles and iron oxide/titanium oxide were produced by co-precipitation and col�gel, respectively. The features of produced nanoparticles were investigated by scanning electron microscope (SEM) and vibrating sample magnetometer (VSM) techniques. In this study, the toxicity tests of effluent were performed by the activity of dehydrogenase enzyme reducing Alamar Blue method. Based on statistical analyzes (R 2 = 0.996), the values of optimal pH, contact time, and nanoparticle concentration were obtained at 6.75, 65 min, and 550 mg/L in the removal of diazinon, respectively. In this case, the efficiency of removing diazinon was 94.15. By analyzing the effluent, eight by-products due to the degradation of diazinon were determined with the probability of correct detection above 50. Based on the Alamar Blue reduction test (ABR), the effective concentrations of 50 (EC 50 ) and the no observed effect concentration (NOEC) for E. coli were obtained 2340 and 18 mg/L, respectively. Based on the results, it was found that the photochemical process TiO 2 /Fe 3 O 4 has high efficiency on the removal of diazinon and there is a significant relation (p value &lt; 0.05) between dehydrogenase activity of E. coli bacteria and reduction of Alamar Blue. © 2018, Accademia Nazionale dei Lincei

Modeling photocatalytic degradation of diazinon from aqueous solutions and effluent toxicity risk assessment using Escherichia coli LMG 15862

In this study, modeling and degradation of diazinon from contaminated water by advanced oxidation process together with a new test for effluent bioassay using E. coli were investigated. The experiments were designed based on response surface methodology. Nanoparticles (NPs) were synthesized using the sol�gel method. The shape characteristics and specifications of elements in the nanoparticles were characterized using scanning electron microscope and energy dispersive X-ray, respectively. Diazinon was measured using high performance liquid chromatography device and by-products due to its decomposition were identified by gas chromatography-mass (GC�MS). In the present study, effluent bioassay tests were conducted by defining the rate of dehydrogenase enzyme reducing alamar blue method. According to statistical analyses (R2 = 0.986), the optimized values for pH, dose of NPs, and contact time were found to be 6.75, 775 mg/L, and 65 min, respectively. At these conditions, 96.06 of the diazinon was removed. Four main by-products, diazoxon, 7-methyl-3-octyne, 2-isopropyl-6-methyl-4pyrimidinol and diethyl phosphonate were detected. According to the alamar blue reducing (ABR) test, 50 effective concentration, no observed effect concentration, and 100 effective concentration (EC100) for the mortality rate of E. coli were obtained as 2.275, 0.839, and 4.430 mg/L, respectively. Based on the results obtained, it was found that mentioned process was high efficiency in removing diazinon, and also a significant relationship between toxicity assessment tests were obtained (P &lt; 0.05). © 2018, The Author(s)