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Microplastics (MPs) are emerging pollutants that pose significant risks to ecosystems due to their inherent toxicity, capacity to accumulate various pollutants, and potential for synergistic impacts. Given these concerns, the focus of this research is on the critical need for effective MPs removal from aquatic environments. Using BBD method, this study aimed to identify the key parameters affecting the removal of MPs by algal biomass from aqueous solutions. The investigation specifically analyzed the effects of varying initial PS concentrations (100 to 900 mg/L), pH values (4 to 10), reaction durations (20 to 40 min), and C. vulgaris dosages (50 to 400 mg/L). Data analysis indicated that QM best described the experimental findings, leading to the identification of optimal conditions for PS removal: a pH of 7.5, a reaction time of 31.90 min, a C. vulgaris dosage of 274.05 mg/L, and a PS level of 789.37 mg/L. Under these conditions, the study achieved a maximum removal efficiency of 73.01% for PS. These outcomes demonstrate the significant potential of C. vulgaris in efficiently removing PS from water. Furthermore, using algae as a green, eco-friendly alternative to conventional chemical coagulants offers a practical and sustainable approach to addressing MPs pollution in our water systems. [ABSTRACT FROM AUTHOR]

Multi-criteria decision-making (MCDM) can introduce the best option based on evidence. We integrated the Analytic Hierarchy Process (AHP) and the Technique for Order of Preference by Similarity to the Ideal Solution (TOPSIS) to prioritize the alternatives for photocatalytic diazinon removal in a bench scale and characterized TiO2-MIL-53(Fe) for this purpose. Criteria and alternatives were listed based on systematic literature reviews and expert opinions. Then, AHP and TOPSIS questionnaires were developed and distributed to an expert panel for pairwise comparisons. We converted the linguistic variables into the corresponding fuzzy values and used R for mathematical calculations. Then, TiO2-MIL-53(Fe) was synthesized and characterized for diazinon removal under LED visible light. The AHP ranked criteria as availability > degradation efficiency > safety for the environment > material cost > energy consumption > mineralization efficiency > photocatalyst reusability > safety for personnel > equipment cost. Based on TOPSIS, the order of alternatives was TiO2-containing/Visible light > ZnO-containing/UV light > TiO2-containing/UV light > ZnO-containing/Visible light > WO3-containing/UV light. With a bandgap of 1.8 eV, TiO2-MIL-53(Fe) could remove 89.35% of diazinon at 10 mg/L diazinon concentration, 750 mg/L catalyst dose, pH 6.8, and 180-min reaction time. Hybrid AHP-TOPSIS identified the best option for photocatalytic diazinon removal from aqueous solutions. Thus, MCDM techniques can use systematic review results to overcome the uncertainty in designing experimental studies. [ABSTRACT FROM AUTHOR]

Background and objective: Previous studies showed controversial results of the relationship between fluoride exposure through drinking water and elevated blood pressure. We conducted a systematic review and meta-analysis to assess the direct relationship of drinking water fluoride exposure with blood pressure and essential hypertension prevalence in general populations. Methods: We conducted a systematic search in databases including Web of Knowledge, PubMed, Scopus, and Embase by MeSH and non-MeSH terms for relevant studies with any design published until August 2019, with no limitation in time and language. The pooled effect measure was calculated within a 95% confidence interval (CI). Results: Our search retrieved 630 journal articles, six of which were eligible for data extraction. The random-effects model found significantly higher systolic blood pressure (mean difference = 6.49 mmHg; 95% CI 3.73–9.25; p value < 0.01) and diastolic blood pressure (mean difference = 4.33 mmHg; 95% CI 1.39–7.26; p value < 0.01) in groups exposed to high-fluoride drinking water than in groups exposed to normal/low-fluoride drinking water. A significant relationship was also found between high-fluoride drinking water and essential hypertension (odds ratio = 2.14; 95% CI 1.02–4.49; p value = 0.045). Conclusion: The risk of elevated blood pressure increases in the general population of fluoride endemic areas. However, more research is needed to make a firm conclusion about the adverse effects of excess fluoride intake on the cardiovascular system at the individual level. [ABSTRACT FROM AUTHOR]

Purpose: Open flames of gas and charcoal can induce polycyclic aromatic hydrocarbons (PAHs) in cooked meat. The current study aimed to compare the effect of gas and charcoal open flames on the induction of PAHs in cooked meat using a meta-analysis approach. Methods: A systematic review of the literature was conducted electronically based on the PRISMA guidelines. Experimental studies comparing the PAHs content of cooked meat over open flames of gas and charcoal were searched using the appropriate keywords until June 2018. Results: Of 1137 papers retrieved, 7 with a total sample size of 474 meat samples were used in the meta-analysis. The mean difference (MD) between the gas and charcoal cooking methods in the induction of each PAH was 2.053 μg/Kg. (95%CI: 1.022–3.085 μg/Kg; P < 0.001). The subgroup analysis of 17 trials indicated the difference between the two cooking methods increases when red meat rather than white meat is cooked (MD in red meat: 3.499 μg/Kg; 95%CI: 2.030–4.967; P < 0.0001 vs. MD in white meat: 3.319 μg/Kg; 95% CI: 1.689–4.950; P < 0.0001). Interestingly, studies that analyzed meat samples for fewer PAHs (cut-off ≤7) found a much wider difference between gas and charcoal-cooked meat (MD: 5.106 μg/Kg; (95% CI: 2.162–8.049; P < 0.001 in studies with ≤7 PAHs vs. MD: 1.447 μg/Kg; 95% CI: 0.628–2.266; P < 0.001 in studies with >7 PAHs). Conclusions: It is necessary to avoid open flames of charcoal as the heat source or change the geometry of charcoal-fired cookstoves to prevent fat dripping on the fire and thus, excessive PAHs induction. [ABSTRACT FROM AUTHOR]

Sawdust of Melia azedarach wood was investigated for removal of BR46 dye and Cu2+ from a binary-solute system. A central composite design was used to determine the effect of various variables including the initial concentration of dye (x1) and Cu2+ (x2), solution pH (x3), contact time (x4), and adsorbent dose (x5) in the process. Fourier transform infrared spectroscopy (FTIR) was utilized to characterize the surface chemistry of pristine- and solute-loaded sawdust. The results of FTIR showed that the functional groups, especially OH groups, on the sorbent surface are capable of adsorbing cationic dye and heavy metal. The mean removal efficiency of BR46 and Cu2+ was obtained as 92.07% and 92.72%, respectively. The experiments indicated the antagonistic adsorption of the cationic dye and heavy metal in a binary system. Adsorbent dose and contact time had the highest and lowest impacts on the decolorization efficiency, respectively, while solution pH and adsorbent dose were the most and the least influential variables on the copper removal, respectively. Adsorption isotherm studies revealed that the experimental data were better fitted to the Langmuir isotherm model. According to the study, adsorption process onto sawdust of M. azedarach can be considered as a choice for economical treatment of polluted effluents of the textile industry. [ABSTRACT FROM AUTHOR]

Magnetite nanosorbents are known with high sorption capacity and ease of solid phase separation from surrounding liquid by the imposed external magnetic field. In this study, magnetite nanoparticles (MNPs) and silica‐coated magnetite nanoparticles (Si‐MNPs) were prepared and used for the removal of arsenic (III) from aqueous solutions. The nanosorbents were characterized by transmission electron microscope, X‐ray diffraction, Fourier transform infrared spectroscopy, and vibrating sample magnetometer. The spherical Fe3O4 nanoparticles in diameter of about 100 nm and SiO2 shells of 12 nm were formed. The saturation magnetization was found to be 78 and 58 e mug–1 for MNPs and Si‐MNPs, respectively. Under optimal conditions, both nanosorbents were very efficient for arsenite uptake (removal efficiency ≥99%). The highest removal percentage was obtained near PZC of nanosorbents where the net surface charge was zero. The MNPs exhibited higher sorption capacities in comparison with Si‐MNPs although they tended to be agglomerated in higher applied doses. The kinetic of experiments indicated the best fit to the pseudo‐second order model. Furthermore, the experimental data were best described by the Langmuir model. This study demonstrated the effectiveness of bare and silica coated magnetic nanoparticles to remove trace concentrations of arsenic (III) in water environment. © 2017 American Institute of Chemical Engineers Environ Prog, 37: 951–960, 2018 [ABSTRACT FROM AUTHOR]

Degradation of Clindamycin phosphate (CMP) was studied in aqueous solutions by an anodic oxidation process under galvanostatic conditions. The electrolysis cell consisted of a Ti/SnO2-Sb anode, prepared by dip-coating technique, and a 316 stainless steel cathode, both of which had a surface area of 6 cm2. The effects of critical factors, including CMP concentration, current density, initial pH, and the supporting electrolyte were evaluated. The electrochemical oxidation of CMP was controlled by mass transport within the studied range. The kinetic analysis indicated that the degradation reactions followed pseudo-first-order equation. The rate of CMP decay, as well as that of COD removal, decreased with increasing initial concentrations. Better Instantaneous Current Efficiency (ICE) values were obtained at higher organic concentrations, due mainly to the increased mass transfer flux towards nonactive anode surface. Increasing current density and initial pH led to the faster removal of CMP, primarily because of enhanced electrogenerated hydroxyl radicals (•OH) on the anode surface. However, COD reduction was found to be pH independent. The removal rates of CMP and COD were also discussed with respect to the supporting electrolyte in different types and concentrations. The GC-MS analysis indicated that tert-butyl compounds were the major organic intermediates for the electrochemical degradation of Clindamycin. [ABSTRACT FROM AUTHOR]

Background: Annually, large quantities of dyes are produced and consumed in different industries. The discharge of highly colored textile effluents to the aquatic environments causes serious health problems in living organisms. This paper investigates the performance of each of the electro-oxidation and electro-reduction pathways in the removal of reactive red 120 (RR120) from synthetic textile effluents using a novel electrochemical reactor. Methods: In the current study, a two-compartment reactor divided by cellulosic separator was applied in batch mode using graphite anodes and stainless steel cathodes. Central Composite Design was used to design the experiments and find the optimal conditions. The operational parameters were initial dye concentration (100-500 mg L-1), sodium chloride concentration (2500-12,500 mg L-1), electrolysis time (7.5-37.5 min), and current intensity (0.06-0.3 A). Results: The results showed that electro-oxidation was much more efficient than electro-reduction in the removal of RR120. According to the developed models, current intensity was the most effective factor on the electro-oxidation of RR120 as well as in power consumption (Coefficients of 12.06 and 0.73, respectively). With regard to the dye removal through electro-reduction, electrolysis time (coefficient of 8.05) was the most influential factor. Under optimal conditions (RR120 = 200 mg.L-1, NaCl = 7914.29 mg.L-1, current intensity = 0.12 A, and reaction time = 30 min), the dye was removed as 99.44 and 32.38% via electro-oxidation and electro-reduction mechanisms, respectively, with consuming only 1.21 kwhm-3 of electrical energy. Conclusions: According to the results, electro-oxidation using graphite anodes in a cell divided by cellulosic separator is very efficient, compared to electro-reduction, in the removal of RR120 from aqueous solutions. [ABSTRACT FROM AUTHOR]

Copper, as an inseparable part of many industrial discharges, threatens both public and environmental health. In this work, an electrochemical cell utilizing a cellulosic separator was used to evaluate Cu removal using graphite anodes and stainless steel cathodes in a continuous-flow mode reactor. In the experimental matrix, Cu concentration (1-5 mg L-1), electrolysis time (20-90 min), and current intensity (0.1-0.4 A) were employed. Results showed that the maximum removal efficiency of copper was obtained as 99%. The removal efficiency was independent of initial copper concentration and directly related to electrolysis time and current intensity. Energy consumption was more dependent on current intensity than electrolysis time. Under optimal conditions (75.8 min electrolysis time, 0.18 A current intensity, and 3 mg L-1 copper concentration), the removal efficiency was obtained as 91% while 7.05 kWh m-3 electrical energy was consumed. The differences between the actual and predicted data under optimal conditions were 0.42% for copper removal and 0.23% for energy consumption, which signify the performance and reliability of the developed models. The results exhibited the suitability of the electrochemical reduction for copper removal from aqueous solutions, which was facilitated under alkaline conditions prevailing in the cathodic compartment due to applying a cell divided by a cellulosic separator. [ABSTRACT FROM AUTHOR]

The treated sawdust was examined to discover its ability in adsorption of Basic Red 46 (BR46) and Reactive Red 196 (RR196). Response surface methodology was employed to evaluate the effects of initial dye concentration, solution pH, adsorbent dosage, and contact time on the process. The experimental results showed the maximum removal of 99.72 and 98.82% for BR46 and RR196, respectively. The percentage of dye removal decreased with increasing initial dye concentration. The alkaline pH for BR46 cationic dye and the acidic pH for RR196 favored the dye adsorption. The maximum removal rate was attained at the adsorbent dosage of 4 g L-1 for BR46 and 4.5 g L-1 for RR196 within the equilibrium time of 40 and 55 min, respectively. The Langmuir model best described the data with predicting the maximum adsorption capacity of 13.94 and 13.39 mg g-1 for BR46 and RR196, respectively. Kinetic studies revealed the pseudo-second order kinetic model best fitted the experimental results, suggesting that the chemisorption controlled adsorption of both dyes onto treated sawdust. The findings revealed that the sawdust as a recycled waste could be used for efficient removal of cationic and anionic dyes from aqueous solutions. [ABSTRACT FROM AUTHOR]

Adsorption of RR141 (an anionic dye) was carried out onto Melia Azaderach sawdust (MAS) in solutions containing low concentrations of calcium ions. The effect of dye concentration, solution pH, Ca2+ concentration, adsorbent dose, and contact time was investigated by response surface methodology. The results showed that by adding 50 mg L−1 Ca2+ ions, the decolorization rate increased by 3 fold. Cation bridging between anions of RR141 and negatively charged sites of MAS was recognized as the main mechanism for the enhanced dye removal. Higher removal efficiencies were obtained at higher calcium concentrations. Solution pH (4-10) had a negligible effect on the process in presence of bridging Ca2+ ions. Initial dye concentration and adsorbent dose were the most influential factors in the process. The equilibrium time was found to be 46 min, which was unchanged at different dye concentrations (10-100 mg L−1). The dye uptake obeyed the non-linear equations of pseudo-second order kinetic model and Freundlich/Brunauer-Emmett-Teller (BET) isotherm models. The maximum adsorption capacity of 12.92 mg g−1 was calculated from the Langmuir model. Based on the obtained results, adsorptive properties of Melia Azaderach sawdust can be greatly enhanced for uptake of anionic dyes in calcium-containing solutions like natural waters. Copyright © 2015 Curtin University of Technology and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Corrosion and scaling are of the most important properties of potable water and can affect the public health and the economy of water industry. This study was conducted to evaluate the corrosion and scaling potential of potable water of villages covered by in Saqqez, city, Kurdistan province, Iran. In this descriptive study, 142 samples of water were collected from different parts of the distribution network of the village. The samples were analyzed in terms of certain physical and chemical parameters. The results were compared with the qualitative standards of potable water, and corrosion and scaling indices, including langelier saturation index (LSI), ryznar stability index (RSI), larson ratio (LR), and saturation level (SL) were calculated. All the measured parameters were in the range of national and international standards. Biennial mean of LSI, RSI, LR, and SL comprised 0.73, 6.51, .074, and 1.96, respectively. According to the results, the studied potable water was at the status of scaling in terms of LSI and SL, at the status of balanced in terms of RSI, and at the status of corrosion in terms of LR. Frequency distribution of these indices in the studied duration was also performed. In general, it could be argued that the village's potable water was at an acceptable level of corrosion and scaling. However, considering the significant annual changes in the indices, it is recommended to monitor the water every year in terms of corrosion and scaling. [ABSTRACT FROM AUTHOR]

The post treatment of simulated tannery wastewater was evaluated in an electrochemical oxidation process under galvanostatic conditions. A continuous flow reactor divided by a cellulosic membrane consisted of Ti/SnO2–Sb anodes and iron cathodes was used. Central composite design and response surface methodology (RSM) were applied to investigate the effects of six operational parameters, namely initial concentration of total phenols (TPh), total chromium (TCr), total ammonia nitrogen (TAN), flow rate (Q), current intensity (I), and electrode surface area (A). Effectiveness of the innovative cellulosic membrane was proven by considerable pH variations in the anolyte and catholyte chambers. A faster removal rate was observed for TPh and TAN, followed by TCr. The treatment level was very sensitive toQandIin the studied ranges. RSM showed the removal efficiencies of 78.14%, 63.42%, and 86.09% for TPh, TCr, and TAN, respectively, are achieved under optimal conditions with consumption of only 9.03 kWh m−3electrical energy. Chlorinated compounds such as chloroform, 2,4-dichlorophenol, and chlorobenzene were detected as the degradation intermediates. According to the obtained results, electrolysis in the divided cell with cellulosic membrane is a practical, cost-effective method for advanced treatment of tannery effluents. [ABSTRACT FROM AUTHOR]