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A novel type of ion exchanger polymer nanocomposite was achieved and applied for the removal of Cs+ ions from aqueous media. The ion exchanger polymer nanocomposite was prepared based on natural polymer with some chemical modification. The reaction was followed by three steps to prepare the ion exchanger, the first step including the preparation of O-carboxymethyl chitosan (O-CMC), while the second step is the formation of copper potassium hexacyanoferrates nanoparticles (CuKHCF). Finally, the prepared CuKHCF was introducing through polymer matrix of O-CMC to obtain CuKHCF/O-CMC. By Fourier-transform infrared spectroscopy, the composition of the prepared compounds was elucidated. The surface morphology of nanoparticles of CuKHCF and ion exchanger was reported by scanning electron microscopy. Also, transmission electron microscopy was used to report the morphology. Also, the thermal stability was studied using thermogravimetric analysis. A sorption behavior of the ion exchanger toward removal of Cs+ ions from aqueous media was studied at different solution pH, different initial concentration of Cs+ ions, time that Cs+ ions contact with ion exchanger and temperature of solution through batch experiments. From obtained results, the highest capacity was 1.71 mmol/g for Cs+ ions at initial concentration 10 mmol/L and shaking time 2 h at temperature 25°C. By studying the adsorption isotherms and the kinetics, Langmuir model and pseudo-second-order were fitted with this process. Through the data obtained thermodynamic parameters, the nature of sorption process is spontaneous and also endothermic. Also, the sorption process was also achieved by column technique. At pH 7 and an initial concentration of 4 mmoL, the impact of bed depth and flow rate on the adsorption properties of the composite was investigated. Models of Thomas and Yoon-Nelson were employed to assess the performance of the column adsorption. Additionally, it has been shown that 2.0 M KCl may successfully desorb loaded Cs+. Lastly, the synthetic composite was applied successfully five times. [ABSTRACT FROM AUTHOR]

Spherical beads of copper hexacyanoferrate encapsulated with barium alginate (CuHCF)-BA have been prepared by ionotropic gelation of copper nitrate and potassium ferrocyanide with sodium alginate in the presence of Ba(NO3)2 solution. The composition, properties and morphology of the resulting ion exchanger composite have been characterized by Fourier-transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction and thermogravimetric analysis. Batch technique was used to investigate the effects of several parameters such as solution pH, metal ions concentration, contact time and temperature on metal ions uptake. The results indicated that the prepared ion exchanger composite have high affinity towards silver and cesium ions. The ion exchange data have been clarified by Freundlich isotherm model rather than other isotherms such as Langmuir and Temkin for silver ion while the results obtained of cesium ion was best fit with Langmuir isotherm model. Kinetics data have been analyzed using pseudo-first-order and pseudo-second-order and intra-particle diffusion equations. The result revealed that pseudo-secondorder kinetic model was best fit with the obtained data for Ag+ and Cs+. Thermodynamic characteristics show that metal ion exchange process on the (CuHCF)-BA composite is both spontaneous and endothermic for Ag+, while Cs+is not spontaneous but endothermic. [ABSTRACT FROM AUTHOR]

The potato tuber moth (PTM), Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae) is the most destructive pest of stored potato Solanum tuberosum L. tubers in Egypt. The efficacy of ginger, fennel, dill and caraway oils, tilia extract and spinosad for controlling PTM, under storage conditions was studied. Experiment was carried out in the laboratory at 27±2°C and 65±5% RH. Infestation free potato tubers of Sponta variety were brought and sorted. Concentrations of tested treatments were 10, 7, 5 and 2.5 m/l for oils and tilia extract, while it was 1.0, 0.75, 0.50 and 0.25 m/l for spinosad. Three replicates were used for each concentration (20 kg/replicate), in addition, three replicates were used as control. Potato tubers were grouped to a pyramidal form (50×50×50 cm) covered with 50 cm height of treated rice straws by the selected concentrations. The number of mines and produced pupae were recorded every two weeks for three months. At the end of the storage period the weight of the potato tubers and losses were calculated. Results revealed that all treatments were effective in reducing infestation. The highest reduction percentage was in the spinosad, ginger, fennel, dill and caraway oils followed by tillia extract (the least one). Effective tested materials were recommended to be used for controlling P. operculella. [ABSTRACT FROM AUTHOR]

Bioassay tests were carried out to evaluate the toxicity of garlic, jojoba, clove, mustard, camphor and ginger oils against the adults of Sitophilus oryzae (L.). The insecticidal activity of the oils was investigated for 14 days under 28±2°C. The results indicated that a variation in the toxicity of tested botanical oils against the adults of Sitophilus oryzae was found, according to their median lethal concentration (LC50) the toxicity order of these oils was garlic > jojoba > clove > mustard > camphor > ginger. The values of LC50 ranged between 0.150% and 2.194% (v/w) which were recorded after 7 days of the treatment. The least value of LC50 (0.045%) was obtained against the insect tested when garlic oil was applied on wheat grains for 14 days. [ABSTRACT FROM AUTHOR]

Laboratory bioassays were carried out to evaluate the effectiveness of spinosad by using five concentrations (20, 15, 10, 5 and 1 mg/kg) on cowpea seeds against the cowpea beetle, C. maculatus (F.) (Coleoptera: Bruchidae). The results indicated that the adults of cowpea beetle were more susceptible to spinosad at 30ºC (LC50: 0.925 mg/kg, LC90: 28.95 mg/kg) than at 20ºC (LC50: 1.403 mg/kg, LC90: 86.7 mg/kg) after 72 hrs from treatment. The shortest lethal time values (LT50s and LT90s) were obtained at spinosad concentration of 20 mg/kg when the tested insect treated at 30ºC, LT50s and LT90s were 12.68 and 37.95 hrs, respectively, and 16.51 and 65.35 hrs at 20ºC, respectively. Results also showed the greatest reductions in the insect progeny were 100.00 and 99.78% at the highest concentration tested (20 mg/kg) under 20 and 30oC, respectively. Furthermore, control coasts of the tested insect were estimated about 50.5 EL/1000 kg of cowpea seeds. It was concluded that spinosad had considerable toxicity against adults of cowpea beetle and it may be an effective alternative bio-pesticide for control adults of this pest in storage. [ABSTRACT FROM AUTHOR]

It is real and significant that climatic changes affect the pesticide behaviour, but there are no data available on their effect on the pesticide persistence and its preharvest interval (PHI). Therefore, to estimate the potential effect of climatic changes on the fate of indoxacarb in tomato fruits, the decline rate of indoxacarb residues was investigated in winter and summer seasons, for three consecutive years under field condition. Residues of indoxacarb were determined by high performance liquid chromatography with photodiode array detector (HPLCDAD). Recoveries were between 89.5-96.4% with a RSD of 8-15% in tomato at spiked levels of 0.01, 0.05 and 0.1 mg kg-1, respectively. The LOQ of this method was found to be 0.01 mg kg-1 while LOD being 0.005 mg kg-1. Indoxacarb was sprayed on tomato at recommended dosage. Samples of tomato were collected at 0, 1, 3, 5, 7, 10 and 15 days after treatment. The decline rates of indoxacarb were described using first-order kinetics. The results indicated that, the mean half-lives of indoxacarb in tomatoes and PHI changed significantly through all seasons of the trial. The least half-life time and PHI were 1.400 and 2.100 d in summer season of 2014, respectively, while the longest were 2.773 and 4.800 d in winter season of 2012, respectively. Also, a negative correlation coefficient was observed between the averages of air temperature (of days after indoxacarb spraying) in seasons of the experiment and the mean half-life times or PHis. Whereas a positive correlation coefficient was obtained between averages of relative humidities and the mean half-life times or PHis. It was concluded that both air temperature and relative humidity (as a part of climatic factors) play a great role in the interaction with indoxacarb persistence and its PHI. This work would be also helpful for the government of Egypt to establish the MRL of indoxacarb in tomato and to provide guidance on the proper and safe use of this insecticide. [ABSTRACT FROM AUTHOR]