Ciprofloxacin antibiotic removal from aqueous solutions by ZnO nanoparticles coated on ACA: modeling and optimization.

Antibiotics are one of the most widely used drug groups. The presence of antibiotics in urban water sources and sewage creates many environmental and medical risks for humans and other living organisms. In this study, the potential of zinc oxide (ZnO) coated on almond shell activated carbon (ACA-ZnO) in removing ciprofloxacin (CIP) from aqueous solutions was investigated. Almond shell was used to make activated carbon. Zinc oxide nanoparticles were prepared by the sol-gel method, and finally, ZnO nanoparticles were bonded to activated carbon. The effect of independent parameters pH, contact time, adsorbent dose, and initial CIP concentration on CIP removal efficiency using ACA-ZnO was investigated by response surface methodology. Optimal removal was obtained at pH = 5.4, CIP initial concentration = 7.4 mg/L, adsorbent dose = 0.82 g/L, and reaction time = 67.3 min. This study followed a quadratic model (R2 = 0.958). The best model of adsorption isotherm fits with the Freundlich model (R2 = 0.9972) and the maximum capacity was 251.42 mg/g adsorption kinetics, and pseudo-second-order kinetic model (R2 = 0.959). The results of this study showed that ACA-ZnO as an adsorbent is very efficient, without environmental side effect and cost-benefit.

Evaluation of antioxidant and antibacterial interactions between resveratrol and eugenol in carboxymethyl cellulose biodegradable film.

The aim of present study was to compare the in vitro antioxidant and antibacterial properties of carboxymethyl cellulose (CMC) films containing resveratrol (RES) and eugenol (EUG), alone and in combination, and to calculate the dose interactions between them. At first, the total phenolic content of CMC films was evaluated. Then, their antioxidant and antibacterial effects of films were determined using DPPH, reducing power, disk diffusion, and broth dilution methods. Finally, concentrations of RES and EUG which showed better results in the CMC films were added in combination forms to calculate their antioxidant and antibacterial interactions. The results showed that addition of RES and/or EUG to CMC films increased the total phenolic content, free radicals scavenging activity, reducing power, and antibacterial activities of the films (p ≤ .05). Gram-positive bacteria were more susceptible than Gram-negatives. In addition, the combined use of RES and EUG in CMC films had synergistic antioxidant and antagonistic antibacterial effects. The best results belonged to the film containing RES (8 µg/ml) + EUG (8 mg/ml) (p ≤ .05). Considering the results of the present research, we can utilize CMC biodegradable film containing RES and EUG as a natural active packaging in food industry.

Nanoemulsion-based basil seed gum edible film containing resveratrol and clove essential oil: In vitro antioxidant properties and its effect on oxidative stability and sensory characteristic of camel meat during refrigeration storage.

The initial purpose of this study was to compare the in vitro antioxidant interactions between resveratrol (RES) and clove essential oil (CEO) in conventional and nanoemulsion-based basil seed gum (BSG) films. Then, the effects of the best nanoemulsion-based BSG film obtained from in vitro evaluations were determined on oxidative stability and sensory properties of minced camel meat during 20-day storage at 4 °C. The results showed higher in vitro antioxidant activities of nanoemulsion-based BSG films compared to conventional films as well as synergistic effects between RES and CEO. Furthermore, minced camel meat wrapped with nanoemulsion-based BSG film containing RES 4 µg/mL + CEO 10 mg/mL showed better results compared with the control group with the following scores: total carbonyls (0.84 nmol/mg protein), peroxide value (4.03 meq/kg lipid), thiobarbituric acid reactive substance (1.03 mg malondialdehyde/kg), and sensory analysis (overall acceptability: 5.4). The finding of the present study can be applied as a new method in meat and meat products packaging industry.

Modeling of wastewater treatment by Azolla filiculoides using response surface methodology.

INTRODUCTION: Due to the population growth and reduction of water resources, wastewater treatment and reuse vital. As the secondary wastewater treatment processes enable removes a significant amount of P and N, nutrient-rich effluents can cause eutrophication in water bodies. On the other hand, nutrients removal in sewage treatment using mechanical methods is costly and complex. The aquaculture method using Azolla filiculoides could be an appropriate option for removing total phosphorus (TP), total nitrogen (TN), and chemical oxygen demand (COD) from wastewater. MATERIALS AND METHODS: Synthetic wastewater has been prepared in the typical range of municipal wastewater. Two g fresh weight of an acclimatized A.filiculoides was floated in sample bowls each one containing 500 CC prepared wastewater. Total nitrogen, TP, and COD removal by Azolla filiculoides for 21-days were optimized and investigated using the response surface methodology (RSM). For this aim, the D-optimal method was used to optimize the three independent variables (TP concentration (10.8-84.6 mg l- 1), TN concentration (20-99 mg l- 1), and COD concentration (66.26-415 mg l- 1)) for their maximum removal efficiency of them. Experiments were performed on 28 runs in which independent variables were measured using a HACH DR 5000 spectrometer. RESULTS: Predicted R-squared for COD, TP, TN removal, and Azolla mass (responses) have been equal to -0.0897, 0.8514, 0.7779, and 0.5645, respectively. The model was used to maximize Azolla growth and maximize removal efficiency of nitrogen, phosphorus, and COD that occurred in minimum concentrations of TN (20 mg l- 1), TP (10.8 mg l- 1), and COD (66.26 mg l- 1). The removal efficiency of Azolla was obtained 77.5 % for COD, 66.8 % for TP, and 78.1 % for TN in the optimum condition of independent variables. Also, increase of Azolla mass was 239 %, with desirability of 0.66. The difference between model prediction and model validation testing for Azolla mass increase, COD, TN, and TP removal was equal to ± 11.6 %, ± 7.9 %, ± 0.0 %, and ± 1.9 %, respectively. CONCLUSIONS: Azolla could remove phosphorus in nitrogen deficiency or even lack of nitrogen. Results indicate that removal efficiency has an upward trend as the Azolla growth increases. This kind of fern has a significant effect on removing nitrogen, phosphorus, and COD from an aqueous solution. The removal efficiency of TN, TP, and COD at optimum operating conditions showed good agreement with model-predicted removal efficiency.

Combined antioxidant and sensory effects of corn starch films with nanoemulsion of Zataria multiflora essential oil fortified with cinnamaldehyde on fresh ground beef patties.

The aim of this study was to compare the effects of corn starch films containing Zataria multiflora essential oil (ZEO) and cinnamaldehyde (CIN) in conventional, nanoemulsion (NZEO) and fortified nanoemulsion (NZEOC) forms, on pH value, oxidative stability and sensory properties of ground beef patties during 20 days of storage at 4 ±â€¯1 °C. Results of mechanical evaluation indicated that all treated films exhibited lower tensile strength (P ≤ .05) and higher elongation at break (P ≥ .05) than control samples. Also, film containing NZEO showed the best results at the end of storage with the following scores: Peroxide value (3.70 meq/kg of lipid), thiobarbituric acid reactive substance (1.03 mg MDA/kg sample), carbonyl content (0.83 nmol/mg protein) and sensory analysis (overall acceptibility: 5.85). Furthermore, NZEOC had no positive effect on the antioxidant activity compared with NZEO+CIN. The results of the study can be applied to food packaging industry for particularly meat and meat products.

Investigating the photo-Fenton process for treating soil washing wastewater.

PURPOSE: Petroleum hydrocarbons have created numerous problems for water resources. The main objective of this study was focused on the application of advanced oxidation processes (AOPs) in treatment of effluent of petroleum contaminated soil washing operation. METHODS: The AOP process in the present study was run with Fe2+/H2O2 (Fenton's reagent), Fe2+/H2O2/UV (photo-Fenton's reagent) and UV lamp (medium pressure mercury lamp, 400 W) in the batch-mode reactor at laboratory-scale. RESULTS: Various parameters and optimized values which could maximize the removal efficiency of COD were: Fe2+ = 0.1 g/L, H2O2 = 1 g/L, pH = 3 and irradiation time of 120 min. Under the optimal conditions, the removal efficiency of COD and TOC were achieved 86.3% and 68% respectively. The results showed that the reaction of the oxidation of diesel fuel by Fenton and photo-Fenton systems followed second-order kinetic model with reaction rate constants (k) of 7 × 10-6 and 3 × 10-6 l/mg min-1 respectively. CONCLUSIONS: The photo-Fenton process can be used as an effective and environmental friendly method in the degradation of petroleum organic compounds.

Occurrence of aflatoxin B1 in baby foods marketed in Iran.

BACKGROUND: Aflatoxin B1 (AFB1 ), a toxic fungal metabolite that is found in baby foods, can lead to serious complications for children's health. In the present study, 48 commercial baby foods available in the Iranian market were investigated for the presence of AFB1 using a high performance liquid chromatography system that was equipped with post-column photochemical derivatization and a fluorescence detector. RESULTS: Thirty-three out of 48 samples (68.7%) were contaminated with AFB1 at median, maximum and mean concentration levels of 0.11, 15.15 and 2.602 ± 4.065 µg kg-1 , respectively. The AFB1 concentration in 39.6% of the samples was higher than the maximum level established in Iran for AFB1 within baby foods containing milk (0.5 µg kg-1 ). The incidence of AFB1 in rice, wheat and multigrain infant cereal samples was 90%, 25% and 100%, respectively, whereas rice-based baby foods contained the highest levels of AFB1 . CONCLUSION: In the present study, the finding of both high rates and high levels of AFB1 in cereal baby foods indicates the need to reduce AFB1 contamination in these products. Therefore, further monitoring and control of pre- and post-harvest, storage, and manufacturing processes is required. © 2016 Society of Chemical Industry.

Photocatalytic degradation of 4-chlorophenol by UV/H2O2/NiO process in aqueous solution.

The removal of 4-chlorophenol from aqueous phase continues to be an important environmental issue. In this work, the photochemical oxidation of 4-chlorophenol in aqueous solutions in a batch reactor using ultraviolet irradiation, hydrogen peroxide and nickel oxide was studied. The efficiency of the system was evaluated with respect to reaction time, pH, feed concentration of reactants, catalyst load, light intensity, and the reaction rate constant. The concentrations of 4-chlorophenol and chloride ions were determined by high performance liquid chromatography and ion chromatography, respectively. Pure nanosized nickel oxide was characterized by X-ray diffraction and scanning electron microscopy. The results showed that the optimum conditions (the complete 4-chlorophenol removal (100%) at 60 min) were obtained at a neutral pH, with 0.2 mol/L H2O2, and 0.05 g/L of nickel oxide. However, no pH effects were observed in the range of 4-10. Analytical profiles on 4-chlorophenol transformation were consistent with the best line fit of the first-order kinetics. Moreover, the degradation rate constant increased with both UV light intensity and decreasing initial concentration of 4-chlorophenol. Finally, the results of mineralization and chloride ions studies indicated that dechlorination was better accomplished but more time was required to completely mineralize 4-chlorophenol into water and carbon dioxide.