Removal of malathion from various waters by advanced oxidation processes

Summary: The degradation of malathion was investigated under various conditions, including ultrasound (US) irradiation, ultraviolet (UV) irradiation, and the combination of US/UV, UV/ZnO, UV/H2O2, and US/UV/ZnO/H2O2. In addition, the effect of the operational parameters, such as the initial concentration of the catalyst, the initial malathion concentration, the initial salt concentration (NaHCO3 and Na2SO4), and pH, were studied. Analyses were performed by a gas chromatography-mass spectroscopy instrument. The k values were in the following order: US/UV/H2O2/ZnO > US/UV > UV/ZnO > UV/H2O2 > UV > US. ZnO concentration of 100 mg/l, malathion initial concentration of 200 μg/l, H2O2 concentration of 30 mg/l, pH of 9, and irradiation time of 105 min were the optimum conditions for degrading malathion by the US/UV/H2O2/ZnO system. Additionally, the optimized parameters were also tested for the treatment of an actual water sample containing the pesticide. As a result, the efficiency of the US/UV/H2O2/ZnO system was higher in the distilled water sample than in the actual water sample. © 2015, Chemical Society of Pakistan. All rights reserved

PHOTOCATALYTIC DEGRADATION OF CHLORPYRIFOS IN WATER USING TITANIUM DIOXIDE AND ZINC OXIDE

In the present work, degradation of chlorpyrifos in water was investigated using semiconductor oxide catalysts, i.e. zinc oxide (ZnO) and titanium dioxide (TiO2). The influence of various parameters, such as type of the catalyst, irradiation time, catalyst concentrations, pH, and sodium bicarbonate salt was also studied. Results indicated that the optimal concentration of the catalyst was 0.15 g/L. It was also found that TiO2 is a better catalyst than ZnO under the same photocatalytic reaction conditions. The highest removal efficiency was achieved at pH 9. Results from the present study suggested that the photodegradation efficiency of pesticides increases with the increase of the illumination time. The photodegradation efficiency of chlorpyrifos was found to be 80% and 90% for UV/ZnO and UV/TiO2, respectively. Photodegradation in the presence of sodium bicarbonate was slower in comparison to that without the salt. In addition, the efficiency of photocatalytic degradation in distilled water was higher than in natural water

2-{[(4-{[(2-Hydroxyphenyl)(phenyl)methylidene]amino}butyl)imino](phenyl) methyl}phenol.

The asymmetric unit of the title compound, C 30H 28N 2O 2, comprises half of a potential tetra-dentate Schiff base ligand; an inversion centre is situtated at the center of the butane-diamine spacer. The central methylene segment of the diamine spacer is disordered over two positions with a refined siteoccupancy ratio of 0.651 (7):0.349 (7). The phenyl ring and the hydroxysubstituted benzene ring are almost perpendicular to each other, with a dihedral angle of 87.90 (8) Å. intramolecular O - H⋯N hydrogen bonds make S(6) ring motifs

4-Bromo-2-[(E)-(2-{2-[(2-{[(E)-5-bromo-2-hydroxybenzylidene]amino}phenyl)sulfanyl]ethylsulfanyl}phenyl)iminomethyl]phe-nol.

The asymmetric unit of the title compound, C28H22Br2N2O2S2, comprises half of a Schiff base ligand, the whole mol­ecule being generated by a crystallographic inversion center located at the mid-point of the C—C bond of the central methyl­ene segment. Intra­molecular O—H⋯N and O—H⋯S hydrogen bonds make S(6) and S(5) ring motifs, respectively. In the crystal, there are no significant inter­molecular inter­actions

Gene cloning and evaluation of the Acinetobacter baumannii nlpD gene expression in human dermal fibroblast cells using RT-PCR

Background: Acinetobacter baumannii is one of the highly antibiotic-resistant bacteria in the world. This bacterium is a cause of endemic and epidemic nosocomial infections and despite many efforts, there is still no effective vaccine agains it. NlpD is one of the important antigenic agents that stimulate the immune system. So, the aim of this study was to examine gene cloning and expression of the nlpD gene of A. baumannii in human dermal fibroblast (HDF) cells. Materials and Methods: In this experimental study, the nlpD gene was amplified from A. baumannii genome using polymerase chain reaction (PCR). Then, the nlpD gene was cloned and sub-cloned in pTZ57R/T and pIRES2-EGFP vectors, respectively. Confirmation of gene cloning was performed by PCR, restriction endonuclease and sequencing methods. The final pIRES2-EGFP-nlpD recombinant vector was transformed into HDF cells using electroporation and the expression of target gene was evaluated by RT-PCR. Results: In this study, the 831 bp nlpD gene of A. baumannii was amplified successfully. Also, the results of the study showed that the recombinant pIRES2-EGFP-nlpD final construct was produced. Observation of the 831 bp band on agarose gel in transformed cells compared to control cells confirmed the nlpD gene expression in HDF cells. Conclusion: The final construct that generates in this study can express the nlpD gene of A. baumannii in eukaryotic cells. Successful expression of the target gene can be used as a new recombinant vaccine in animal model. The pIRES2-EGFP-nlpD recombinant vector has also the potential as a gene vaccine for future research

Computational analysis of magnetohydrodynamic natural convection in a square cavity with a thin fin

A numerical study of laminar natural convection in a square cavity with a thin fin that is under the influence of a uniform magnetic field is presented. The side walls of the cavity are kept at different temperatures and the horizontal walls are thermally insulated. An Adaptive Network-based Fuzzy Inference System (ANFIS) approach and an Artificial Neural Network (ANN) approach are developed, trained and validated using the results of Computational Fluid Dynamics (CFD) analysis. The effects of pertinent parameters on fluid flow and heat transfer characteristics are studied. Among these parameters are the Rayleigh number (103≤≤;106), the Hartmann number (0≤&Ha;≤;100), the position of the thin fin (0.1≤ Y p≤) and the length of the thin fin (0≤Lp≤0.8). The results show that ANFIS and ANN can successfully predict the fluid flow and heat transfer behaviour within the cavity in less time without compromising accuracy. In most cases, ANFIS can predict the results more accurately than ANN