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Dyestuffs are very persistent in nature and are present in large number in wastewater of different industries. The wastewater of different industries contains many pollutants which are hazardous for human health and environment. In the present study, sonophotocatalytic degradation of Acid red 17 (AR-17) dye in aqueous solution was investigated using silver impregnated zinc oxide (Ag/ZnO). Silver impregnated zinc oxide (Ag/ZnO) catalyst was prepared by wet impregnation method and characterized by SEM, EDX, XRD and band gap. Removal of dye was carried out at 40 kHz frequency ultrasound waves under visible light (Tungsten lamp) of 100 W. The effect of various operating conditions and reagents like H2O2 concentration, pH of the solution, amount of catalyst and concentration of AR-17 dye were investigated. At the own pH of dye using 7 mmole H2O2 concentration 92.9 % degradation of acid red 17 was observed. The degradation increased with increase in irradiation and sonication time of 30 minutes and with 0.25 g /100 mL Ag/ZnO highest degradation 92.94 % was found. The TOC analysis was also carried out sonophotocatalytically and 80 % removal of total organic compounds was observed. The degradation of AR-17 followed pseudo-second-order kinetics with high value of correlation coefficient.

A comparative study of Cu-impregnated ZnO and Ni-impregnated ZnO for the sonophotocatalytic degradation of cefixime in aqueous solution under visible light irradiation was carried out. Sonophotocatalysts were prepared by using a wet impregnation method and characterised using different spectroscopic techniques. Sonophotocatalytic efficiency of degradation is superior to photolysis, sonolysis, photocatalysis and sonocatalysis. Different operational parameters like pH, catalyst dosage, different enhancers, scavenger���s effect, initial concentration of drug, reusability of catalyst and catalyst settling time were optimised. Optimum time of 30 min was found for the 45.7% degradation of cefixime using Cu-ZnO and 42.2% degradation using Ni-ZnO photocatalysts at pH 10. The degradation of cefixime increased from 75.3% to 100% with 5 mmol of hydrogen peroxide using 0.1 g/ L of Cu-ZnO and 99.8% using 0.15 g/L of Ni-ZnO, while other oxidising agents were found less effective using (Cu���ZnO-Ni-ZnO) photocatalyst. A very little decrease in degradation was observed with different types of scavengers. Catalyst reusability was checked up to three cycles and good results up to three cycles were achieved and followed pseudo-first-order kinetic model. Furthermore, the sonophotocatalytic activity was tested for real pharmaceutical wastewater resulting in 91 and 89% removal of total organic carbon (TOC) using (Cu-ZnO-Ni-ZnO), respectively. The proposed method was successfully applied on commercial and synthetic sample with satisfactory results.

In this study, fuller’s earth (FE) modified with sodium dodecylbenzene sulphonic acid was used for adsorptive removal of fenoxaprop-p-ethyl (FPE) herbicide from water samples and statistical validation of the experimental observations was accomplished. All the adsorption experiments were conducted in batch mode. The effect of pH, agitation time, adsorbent dose and initial herbicide concentration on adsorption process was studied. About 98.5% adsorption efficiency was achieved at initial analyte concentration of 1000 mg L-1 at pH 6 within 60 min at adsorbent dose of 0.1 g. The adsorption kinetics were studied and pseudo-second-order kinetic model was found to follow the adsorption kinetics with R2=0.998. The isotherm studies show that the adsorption data fit well to the Freundlich isotherms. In statistical evaluation, the individual as well as the interaction effect of various factors on adsorption was investigated and it was found that concentration, pH and adsorbent dose are the significant factors with p values of 0.0001, 0.004 and 0.006 respectively, while contact time was found statistically insignificant having p value greater than 0.05. The coefficient of determination (R2=0.930) shows that % adsorption is highly dependent on the studied factors and their interactions. Under the optimized set of conditions, high absorption capacity of 200.22 mg g-1 was achieved.

A fast and sensitive method was developed for determination of glyphosate, using flow injection analysis. The analyte was converted to a photoactive product that shows maximum absorbance at 405 nm. Beer’s law was obeyed over a range of 0.7–20 μgmL–1. The limit of detection and quantification were found to be 0.20±0.01 and 0.70±0.02 μgmL–1 with a high sample throughput of 60 samples h–1. The investigation of interference effect shows that among the compounds studied, only aminomethyl phosphonic acid exhibits a signal enhancing effect when present in higher concentration ratio with the analyte and this can be assumed to be a limitation of the present method. The percentage recoveries and residue of glyphosate in wheat grains samples, were found in the range of 90.0 ± 0.6 % to 93.0 ± 0.6 % and 1.13 ± 0.009 μg g–1, respectively.Keywords: Glyphosate, photoactive, absorbance, flow injection analysis, residue

WOS: 000363815600019, PubMed ID: 26695244, Magnetic allylamine modified graphene oxide-poly(vinyl acetate-co-divinylbenzene) (MGO-DVB-VA) was synthesized and used for magnetic solid phase extraction of Pb(II), Cd(II), Cu(II), Ni(II) and Co(II) prior to their determination by flame atomic absorption spectroscopy. The adsorbent surface functional group was characterized by using FT-IR and Raman spectroscopy. XRD pattern was used to determine the layers of GO. Surface morphology and elemental composition of the adsorbent were evaluated by using SEM and EDX analysis. Various parameters, effecting adsorption efficiency like initial solution pH, adsorbent dose, type and volume of eluent, volume of sample and diverse ions effects were optimized. The preconcentration factor (PF) is 40 for all the metals and the limits of detection for Pb, Cd, Cu, Ni and Co are in the range of 037-239 mu g L-1 and relative standard deviation below 3.1%. The method was validated by using the method for certified reference materials (Tobacco Leaves (INCT-OBTL-5), Tomato Leaves (1573a), Certified Water (SPS-ww2) and Certified Water (TMDA 64-2)). The method was successfully applied for natural water and food samples. (C) 2015 Elsevier B.V. All rights reserved., Scientific and Technological Research Council of Turkey (TUBITAK), Mansoor Khan is thankful to the Scientific and Technological Research Council of Turkey (TUBITAK) under "2216 Research Fellowship Programme for Foreign Citizens" for financial support.