Experimental design, modeling and mechanism of cationic dyes biosorption on to magnetic chitosan-lutaraldehyde composite

Magnetic separation of toxic dyes has become a potential and effective method in wastewater treatments. In present research, a facile in situ one step co-precipitation synthetic approach is used to develop water-dispersible Fe 3 O 4 /Chitosan/Glutaraldehyde nanocomposites (MCS-GA) as an efficient adsorbent for the removal of Crystal Violet (CV) from aqueous solution. The physicochemical properties of the MCS-GA were investigated using FTIR, SEM, TEM, XRD, BET, and VSM techniques. 5-level and 3-factors central composite design (CCD) combined with the response surface methodology (RSM) was applied to investigate the statistical relationships between independent variables i.e. initial pH, adsorbent dosage, initial dye concentration and adsorption process as response. The optimal values of the parameters for the best efficiency (99.99) were as follows: pH of 11, the initial dye concentration of 60 mg L �1 and MCS-GA dosage of 0.817 g L �1 , respectively. The adsorption equilibrium and kinetic data were fitted with the Langmuir monolayer isotherm model (q max : 105.467 mg g �1 , R 2 : 0.996) and pseudo-second order kinetics (R 2 : 0.960). Thermodynamic parameters (R 2 > 0.941, �H°: 690.609�896.006 kJ mol �1 , �G°: �1.6849 to �13.4872 kJ mol �1 , �S°: 0.168�0.232 kJ mol �1 K �1 ) also indicated CV adsorption is feasible, spontaneous and endothermic in nature. Overall, taking into account the excellent efficiency, good regeneration and acceptable performance in real terms, MCS-GA can be introduced as a promising absorbent for dyes removal from the textile wastewater. © 2019 Elsevier B.V

Dataset for effect comparison of irrigation by wastewater and ground water on amount of heavy metals in soil and vegetables: Accumulation, transfer factor and health risk assessment

The irrigation source plays an important role in the amount of contaminates in soil and cultivated agricultural products. In this study, the concentration and human health risks of heavy metals (Zn, Mn, Cu, Cr, Cd and Pb) were evaluated in soil, water and vegetables collected from two sites (FGW: Farms irrigated with ground water, FWW: Farms irrigated with wastewater) of Bushehr, Iran. The trend of heavy metals concentration in vegetables from either site was in the following order: Mn ˃ Zn ˃ Cu ˃ Pb ˃ Cr ˃ Cd. Except Cd and Pb, the concentration of heavy metals was in the range of European Union (2006) permissible limit. THQ (Target hazard quotient) values were the highest in Mn followed by the Pb, Cd, Cu, Zn and Cr. Mn, Pb and Cd exceeded safe limit of THQ in several cases, while THQ of other heavy metals was in the range of safe limit. Based on the results, it can be concluded that heavy metals contamination in vegetables grown in Bushehr, especially in FWW site, may pose a great health risks to the local inhabitant through consumption of vegetables. Therefore, it is recommended that the discharge of industrial and municipal wastewater into water resources witch used for vegetable irrigation should be the first step in controlling the level of heavy metals in vegetable

Dataset for effect comparison of irrigation by wastewater and ground water on amount of heavy metals in soil and vegetables: Accumulation, transfer factor and health risk assessment

The irrigation source plays an important role in the amount of contaminates in soil and cultivated agricultural products. In this study, the concentration and human health risks of heavy metals (Zn, Mn, Cu, Cr, Cd and Pb) were evaluated in soil, water and vegetables collected from two sites (FGW: Farms irrigated with ground water, FWW: Farms irrigated with wastewater) of Bushehr, Iran. The trend of heavy metals concentration in vegetables from either site was in the following order: Mn ˃ Zn ˃ Cu ˃ Pb ˃ Cr ˃ Cd. Except Cd and Pb, the concentration of heavy metals was in the range of European Union (2006) permissible limit. THQ (Target hazard quotient) values were the highest in Mn followed by the Pb, Cd, Cu, Zn and Cr. Mn, Pb and Cd exceeded safe limit of THQ in several cases, while THQ of other heavy metals was in the range of safe limit. Based on the results, it can be concluded that heavy metals contamination in vegetables grown in Bushehr, especially in FWW site, may pose a great health risks to the local inhabitant through consumption of vegetables. Therefore, it is recommended that the discharge of industrial and municipal wastewater into water resources witch used for vegetable irrigation should be the first step in controlling the level of heavy metals in vegetable

Speciation of As()/As(V) and Total Inorganic Arsenic in Biological Fluids Using New Mode of Liquid-Phase Microextraction and Electrothermal Atomic Absorption Spectrometry

In this paper, a new extraction method based on countercurrent liquid–liquid microextraction (CLLME) has been developed for the extraction and preconcentration of inorganic arsenic (iAs) in plasma and urine samples prior to their analysis by electrothermal atomic absorption spectrometry (ETAAS). In this method, firstly, 5 ml of water is added to the extraction vessel. Then 30.0 μl of the extracting solvent is added to it in order for the extracting solvent to be placed in the narrow-necked vessel. In total, 10 ml of a standard solution or a pretreated real sample is added to the sample container and it is connected to the extraction vessel via a connector. While opening the embedded valve at the bottom of the sample container and the one in the extraction vessel, the sample solution flows into the extracting solvent with the same flow rate, leading to the successful extraction of metal ligand into the extracting organic solvent. Under the optimum conditions, calibration curves are linear in the range of 0.1–50 μg l−1, and limit of detections (LODs) are in the range of 0.03–0.05 μg l−1. The enhancement factor and enrichment factor were in the range of 220–240 and 198–212, respectively. Repeatability (intra-day) and reproducibility (inter-day) of method based on seven replicate measurements of 5.0 μg l−1 of arsenic were in the range of 2.3–3.5% and 4.0–5.7%, respectively. The applicability of the proposed CLLME and ETAAS methods was demonstrated by analyzing the iAs in spiked urine and plasma samples. The obtained recoveries of the arsenic in the range of 92–107% indicated the excellent capability of the developed method for speciation of arsenic from plasma and urine sample

Extraction and determination of heavy metals in soil and vegetables irrigated with treated municipal wastewater using new mode of dispersive liquid�liquid microextraction based on the solidified deep eutectic solvent followed by GFAAS

BACKGROUND: In this research, a new extraction method based on dispersive liquid�liquid microextraction and the solidification of deep eutectic solvent has been developed for the determination of heavy metals in soil and vegetables prior to their analysis by graphite furnace atomic absorption spectrometry (GFAAS). In this method, a green solvent consisting of 1-decyl-3-methylimidazolium chloride and 1-undecanol was used as an extraction solvent, yielding the advantages of material stability, low density and a suitable freezing point near room temperature. RESULTS: Under optimal conditions, enrichment factors are in the range of 114�172. The calibration graphs are linear in the range of 0.02�200 µg kg�1 and limits of detection are in the range of 0.01�0.03 µg kg�1. Repeatability and reproducibility of the method based on seven replicate measurements of 0.80 µg kg�1 of Hg and 0.20 µg kg�1 of Pb and Cd in analyzed samples were in the range of 2.3�4.1 and 3.7�6.6, respectively. CONCLUSION: A new deep eutectic solvent consists of two parts: 1-decyl-3-methylimidazolium chloride and 1-undecanol in a molar ratio of 1:2. The accuracy of the proposed procedure was also assessed by determining the concentration of the studied metal ions in a polluted farmland soil standard reference material. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industr

Epidemiological characteristics of patients with COVID-19 in Southwest of Iran from February 19 to June 20, 2020

Background:COVID-19 spread rapidly throughout the world and affected many people. The purpose of this study was to investigate the epidemiological characteristics of patients with COVID-19 in southwest of Iran from February 19 to June 20, 2020. Methods: In this retrospective study, the epidemiological characteristics of 7313 patients with COVID-19 in southwest of Iran were analyzed and reported from February 19, 2020, to the end of Jun,2020. Data were extracted from electronic records in hospitals. Sex ratio and mortality rate of the disease were calculated.A multiple logistic regression analysis was used to evaluate the factors affecting mortality.Results: From all patients studied, 3920 (53 5) were men and 2066 (28.24) were in the age 30 to 40 years age group. The case fatality rate of the disease based on the total number of patients (hospitalized and nonhospitalized) was 4.84. The highest mortality rate was seen in patients with various cancers and in those aged over 80 years. The most common symptoms in patients were fever and cough, diabetes, hypertension, and cardiovascular diseases. Logistic regression results also showed that the chances of death in the 70-60 and 80-70 years age group were 5.94 (OR, 5.94; 95 CI, 2.14-16.43) and 8.63 (OR, 8.63, 95 CI, 3.09-24.14) compared to 10-20 years age group. Conclusion: These results indicate the need to increase primary care, provide the necessary equipment to treat patients, and more importantly, early identification of patients and treatment for them © 2021, Medical Journal of the Islamic Republic of Iran. All Rights Reserved

Application of modified maize hull for removal of Cu(II) ions from aqueous solutions

Discharge of industrial waste containing heavy metals to the environment is a main concern because of their toxicity to many life forms. Adsorption process is one of the conventional methods in order to adsorb heavy metals from wastewater effluents. Therefore, the removal of Cu(II) from aquatic solutions using modified maize hull was investigated. All experiments were performed in batch conditions. The residual Cu(II) concentration was measured by AAS. Upon increasing the adsorbent dosage, pH, and contact time and decreasing Cu(II) concentration, the removal efficiency of Cu(II) ions increased. In optimum conditions, 50% of copper was removed by modified maize hull. The experimental data were best fitted by the Langmuir type 2 model and the adsorption kinetic model followed a pseudo-second order type 1 model. It seems that the use of the modified maize hull to remove Cu(II) ions is very suitable, low-cost, and efficient