Sorption of some radionuclides from liquid waste solutions using anionic clay hydrotalcite sorbent.

129I and 79Se are potentially important anionic radionuclides in safety assessments due to their high mobility, radiotoxicity, and long half life's (1.7 × 107 and 3.27 × 105 years, respectively). This study is interested in the sorption of 131I and 75Se radionuclides onto magnesium iron hydrotalcite (Mg/Fe HTlc). Mg/Fe HTlc was prepared by co-precipitation technique and characterized using different analytical tools such as FT-IR, XRD, XRF, TGA & DTA, SEM, and BET. Results obtained from this study showed that the adsorption process was a very fast equilibrium time (20 min). The distribution coefficient values as a function of pH have high separation factors for 131I at all different pHs. Reaction kinetic obeys the pseudo-second-order model. Maximum sorption capacity for 131I and 75Se has the values 21.45, and 9.25 mg/g respectively. Sorption isotherms are more relevant to a Langmuir isotherm. The % removal of 131I is decreased by increasing the concentration of competing species. The investigation evidenced that the prepared sorbent is suitable for the removal of 131I and 75Se from radioactive waste and could be considered potential material for purification of effluent polluted with these radionuclides.

Fumigant toxicity of some essential oils against Red Flour Beetles, Tribolium castaneum (Herbst) and its safety to mammals / Toxidade fumigante de alguns óleos essenciais contra besouros de farinha vermelha, Tribolium castaneum (Herbst) e sua segurança para mamíferos

Abstract Fumigant activities for three essential oils; Garlic oil (Allium sativum L); Chili pepper (Capsicum annuum L.) and Nigella (Nigella sativa L.) were assessed at different concentrations against the adult and 20-days old larval stages of Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) in the laboratory. The accumulative mortality was observed at different exposure periods (3, 5 and 7 days). The residual effect of garlic oil that was the effective oil, on the treated wheat grains was evaluated with respect to histological changes in the liver, kidney, and stomach of rat fed on this treated wheat. The results showed that the mortality rates of treated stages increased with increasing the time of fumigation treatment. Moreover the highest essential oils toxicity at the Median lethal concentration (LC50) values for exposure periods (3, 5 and 7 days) to fumigation were (126, 53, and 47 mg/L air) for adult stage and were (79, 62, and 41 mg/L air) for larval stage, respectively in the case of Garlic oil treatment. While, the lowest essential oils effective was Nigella oil at the Median lethal concentration (LC50) values for exposure periods (3, 5 and 7 days) to fumigation were (3594, 629, and 335 mg/L air) for adult stage and were (1040, 416, and 227 mg/L air) for larval stage, respectively. The toxicity effect of various essential oils against adults and larvae of T. castaneum at the LC50at 7 days fumigation could be arranged in descending order as follows: Garlic oil, Chili pepper oil, and Nigella oil. The histological changes showed that the organs slightly affected at the fumigation for 3 days. It may be concluded that the garlic essential oil is the good effective fumigant to control T. castaneum in the stored products and it recommended that the fumigation period does not exceed 3 days. The garlic essential oil has the potential for applications in IPM programs for stored-grain pests because of its high volatility and fumigant activity and its safety.

Resumo Atividades fumigantes de três óleos essenciais - óleo de alho (Allium sativum L.); pimenta-malagueta (Capsicum annuum L.) e Nigella (Nigella sativa L.) - foram avaliadas em diferentes concentrações contra adultos e larvas de Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) com 20 dias de idade em laboratório. A mortalidade acumulada foi observada em diferentes períodos de exposição (3, 5 e 7 dias). O efeito residual do óleo de alho, ou seja, o óleo eficaz, nos grãos de trigo tratados foi avaliado em relação às alterações histológicas no fígado, rim e estômago de ratos alimentados com esse trigo tratado. Os resultados mostraram que as taxas de mortalidade dos estágios tratados cresceram com o aumento do tempo de exposição ao tratamento de fumigação. A maior toxidade dos óleos essenciais nos valores de Concentração Letal Média (CL50) para os períodos de exposição (3, 5 e 7 dias) à fumigação foi (126, 53 e 47 mg/L ar) para a fase adulta e (79, 62 e 41 mg/L ar) para a fase de larva, respectivamente no caso do tratamento com o óleo de alho, enquanto que o óleo essencial menos eficaze foi o óleo de Nigella, com valores de CL50 para os períodos de exposição (3, 5 e 7 dias) à fumigação (3594, 629 e 335 mg/L ar) para a fase adulta, e (1040, 416 e 227 mg/L ar) para a fase de larva, respectivamente. O efeito da toxidade de vários óleos essenciais contra adultos e larvas de T. castaneum em LC50 aos sete dias de fumigação pôde ser organizado em ordem decrescente, como segue: óleo de alho, óleo de pimenta e óleo de Nigella. As alterações histológicas mostraram que os órgãos foram levemente afetados na fumigação por três dias. Pode-se concluir que o óleo essencial de alho é um bom fumigante efetivo no controle de T. castaneum nos produtos armazenados, e recomendou-se que o período de fumigação não ultrapassasse três dias. O óleo essencial de alho tem potencial para aplicações em programas de Integrated Pests Management (IPM) para pragas de grãos armazenados, devido à sua alta volatilidade, atividade fumigante e respectiva segurança.

Verification of atmospheric plasma irradiation as an alternative control method for Tribolium castaneum (Herbst) / Verificação da irradiação plasmática atmosférica como método alternativo de controle para Tribolium castaneum (Herbst)

Abstract Radio frequency plasma, RF plasma, has been applied to a number of industrial applications. Laboratory experiments were conducted to determine the RF plasma potential in Tribolium castaneum (Herbst) control. Three treatment variables: (1) helium or argon plasmas; (2) two power levels (50 and 100 watt); and (3) different RF plasma exposure times (0, 20, 40, 60 and 90 seconds) were examined in this study. The susceptibility of T. castaneum to treatment varies as gas, power level, and the exposure time varies. A positive correlation was found between insect mortality percent in treating larvae as well as treated pupae and exposure time to RF plasma and also the power level of irradiation. The results revealed that no live insects were found after a 90 second, 100 watt helium RF plasma treatment. The survival percents of the adults were developed from treated larvae and treated pupae were significantly reduced by increasing of the exposure time or power level. Obtained data indicated that the treatment with RF plasma might be considered as an environmentally compatible or alternative supplement to the other control methods for stored product-pests management.

Resumo Plasma de radiofrequência, plasma de RF, tem sido empregado em diversas aplicações industriais. Experimentos de laboratório foram conduzidos para determinar o potencial de plasma de RF no controle de Tribolium castaneum (Herbst). Foram examinados nesse estudo três variáveis ​​de tratamento: (1) plasma de hélio ou argônio; (2) dois níveis de potência (50 e 100 watts); e (3) diferentes tempos de exposição ao plasma de RF (0, 20, 40, 60 e 90 segundos). A suscetibilidade do T. castaneum ao tratamento varia conforme o gás, o nível de energia e o tempo de exposição. Foi encontrada uma correlação positiva dentre a porcentagem de mortalidade de insetos no tratamento de larvas, bem como as pupas tratadas e o tempo de exposição ao plasma de RF, e também o nível de potência da irradiação. Os resultados revelaram que não foram encontrados insetos vivos após 90 segundos, com 100 watts de tratamento com plasmas de hélio e RF. As porcentagens de sobrevivência dos adultos foram desenvolvidas a partir de larvas tratadas, e as pupas tratadas foram significativamente reduzidas pelo aumento do tempo de exposição ou nível de potência. Os dados obtidos indicaram que o tratamento com plasma de RF pode ser considerado como um suplemento ambientalmente compatível ou alternativo aos outros métodos de controle para o manejo de produtos-pragas armazenados.

Tuning the physicochemical properties of apple pectin films by incorporating chitosan/pectin fiber.

Various biodegradable or edible films were designed to deal with the environmental threats from plastic films. To overcome the defects of pectin film, the feasibility for the incorporation of CH/PE fiber was explored. Micron-scale novel artificial CH/PE fibers in needle, spindle or whisker shape with a diameter around 25 µm were fabricated via a shearing regime in virtue of electrostatic complexing. The incorporation of CH/PE fiber (mixture) and its size-fractioned portions (small and large) substantially changed PE films in diverse ways. Structurally, the fiber-incorporated films were heterogeneous with the fibers concentrated in the upper layer, although they presented similar FT-IR spectra and XRD pattern to PE film. Regarding the film performance, the incorporation of CH/PE fibers, especially the small portion, rendered the PE film with higher values in water-proof ability, thermal stability, break resistibility, stretchability and UV blocking capacity. More importantly, this work provided an innovative strategy to improve the performance of edible films.

Fumigant toxicity of some essential oils against Red Flour Beetles, Tribolium castaneum (Herbst) and its safety to mammals.

Fumigant activities for three essential oils; Garlic oil (Allium sativum L); Chili pepper (Capsicum annuum L.) and Nigella (Nigella sativa L.) were assessed at different concentrations against the adult and 20-days old larval stages of Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) in the laboratory. The accumulative mortality was observed at different exposure periods (3, 5 and 7 days). The residual effect of garlic oil that was the effective oil, on the treated wheat grains was evaluated with respect to histological changes in the liver, kidney, and stomach of rat fed on this treated wheat. The results showed that the mortality rates of treated stages increased with increasing the time of fumigation treatment. Moreover the highest essential oils toxicity at the Median lethal concentration (LC50) values for exposure periods (3, 5 and 7 days) to fumigation were (126, 53, and 47 mg/L air) for adult stage and were (79, 62, and 41 mg/L air) for larval stage, respectively in the case of Garlic oil treatment. While, the lowest essential oils effective was Nigella oil at the Median lethal concentration (LC50) values for exposure periods (3, 5 and 7 days) to fumigation were (3594, 629, and 335 mg/L air) for adult stage and were (1040, 416, and 227 mg/L air) for larval stage, respectively. The toxicity effect of various essential oils against adults and larvae of T. castaneum at the LC50at 7 days fumigation could be arranged in descending order as follows: Garlic oil, Chili pepper oil, and Nigella oil. The histological changes showed that the organs slightly affected at the fumigation for 3 days. It may be concluded that the garlic essential oil is the good effective fumigant to control T. castaneum in the stored products and it recommended that the fumigation period does not exceed 3 days. The garlic essential oil has the potential for applications in IPM programs for stored-grain pests because of its high volatility and fumigant activity and its safety.

Verification of atmospheric plasma irradiation as an alternative control method for Tribolium castaneum (Herbst).

Radio frequency plasma, RF plasma, has been applied to a number of industrial applications. Laboratory experiments were conducted to determine the RF plasma potential in Tribolium castaneum (Herbst) control. Three treatment variables: (1) helium or argon plasmas; (2) two power levels (50 and 100 watt); and (3) different RF plasma exposure times (0, 20, 40, 60 and 90 seconds) were examined in this study. The susceptibility of T. castaneum to treatment varies as gas, power level, and the exposure time varies. A positive correlation was found between insect mortality percent in treating larvae as well as treated pupae and exposure time to RF plasma and also the power level of irradiation. The results revealed that no live insects were found after a 90 second, 100 watt helium RF plasma treatment. The survival percents of the adults were developed from treated larvae and treated pupae were significantly reduced by increasing of the exposure time or power level. Obtained data indicated that the treatment with RF plasma might be considered as an environmentally compatible or alternative supplement to the other control methods for stored product-pests management.

Preparation, characterization and application of Mg/Fe Hydrotalcite as gamma sealed source for spectroscopic measurements.

A feasibility study was conducted to prepare, characterize and apply Mg/Fe Hydrotalcite composite as a core material of γ-sealed source used in spectroscopic measurements. Co-precipitation method was used to prepare the composite. To understand and define the physicochemical properties of the prepared composite, different analytical techniques were used. Optimum conditions for the use of the prepared composite as a core material for a radioactive sealed source were obtained. Finally, radiometric analysis has been done, in addition to testing of both physical and mechanical properties for the prepared sealed source.

Assessment of nano-sized stannic silicomolybdate for the removal of 137Cs, 90Sr, and 141Ce radionuclides from radioactive waste solutions.

Synthesized nano-sized stannic silicomolybdate was tested for the adsorption of 137Cs, 90Sr, and 141Ce radionuclides from radioactive waste solutions using batch experimentations in single metal solution. The sorption examinations were performed under the effect of some key parameters such as (pH, contact time, initial metal concentration, adsorbent weight, and temperature). Isothermal records were found to be well fitted with Langmuir adsorption model. The evaluated mean adsorption energy from the D-R isotherm model has been achieved as 18.25, 34.92, and 37.47 kJ mol-1 for 137Cs, 90Sr, and 141Ce radionuclides respectively, further conferring to the chemical process of the adsorption. The adsorption interaction of 137Cs, 90Sr, and 141Ce radionuclides onto SnSiMo obeyed pseudo-second-order rate equation. The adsorption process was controlled by particle diffusion mechanism, while intraparticle diffusion was not only the rate-limiting step. The positive values obtained for the entropy of activation suggest that there is an important change occurring in the internal structure of SnSiMo throughout the adsorption procedure.

Evaluation of synthetic aluminum silicate modified by magnesia for the removal of 137Cs, 60Co and 152+154Eu from low-level radioactive waste.

The present study concerns the preparation, characterization and testing of an inorganic ion exchanger Aluminum Silicate Modified Magnesia (ASMM). The ASMM composite was prepared using sol-gel technique and characterized by XRD, XRF, FTIR, TGA, DTA, SEM and surface area analysis. The capability of the prepared composite for the removal of (Cs+, Co2+ and Eu3+) from aqueous solution was evaluated. Sorption studies were carried out taking into account important parameters such as (pH, initial concentration, contact time and temperature). Kinetic and isotherm models were applied to the prepared composite, kinetic data is well fitted with pseudo-second order kinetic model, Dubinin-Radushkevich isotherm model indicates that sorption was controlled by chemisorption process. The removal efficiency found to be 80% for Cs+, 90% for Co2+ and 95% for Eu3+.

Verification of atmospheric plasma irradiation as an alternative control method for Tribolium castaneum (Herbst)

Abstract Radio frequency plasma, RF plasma, has been applied to a number of industrial applications. Laboratory experiments were conducted to determine the RF plasma potential in Tribolium castaneum (Herbst) control. Three treatment variables: (1) helium or argon plasmas; (2) two power levels (50 and 100 watt); and (3) different RF plasma exposure times (0, 20, 40, 60 and 90 seconds) were examined in this study. The susceptibility of T. castaneum to treatment varies as gas, power level, and the exposure time varies. A positive correlation was found between insect mortality percent in treating larvae as well as treated pupae and exposure time to RF plasma and also the power level of irradiation. The results revealed that no live insects were found after a 90 second, 100 watt helium RF plasma treatment. The survival percents of the adults were developed from treated larvae and treated pupae were significantly reduced by increasing of the exposure time or power level. Obtained data indicated that the treatment with RF plasma might be considered as an environmentally compatible or alternative supplement to the other control methods for stored product-pests management.

Resumo Plasma de radiofrequência, plasma de RF, tem sido empregado em diversas aplicações industriais. Experimentos de laboratório foram conduzidos para determinar o potencial de plasma de RF no controle de Tribolium castaneum (Herbst). Foram examinados nesse estudo três variáveis de tratamento: (1) plasma de hélio ou argônio; (2) dois níveis de potência (50 e 100 watts); e (3) diferentes tempos de exposição ao plasma de RF (0, 20, 40, 60 e 90 segundos). A suscetibilidade do T. castaneum ao tratamento varia conforme o gás, o nível de energia e o tempo de exposição. Foi encontrada uma correlação positiva dentre a porcentagem de mortalidade de insetos no tratamento de larvas, bem como as pupas tratadas e o tempo de exposição ao plasma de RF, e também o nível de potência da irradiação. Os resultados revelaram que não foram encontrados insetos vivos após 90 segundos, com 100 watts de tratamento com plasmas de hélio e RF. As porcentagens de sobrevivência dos adultos foram desenvolvidas a partir de larvas tratadas, e as pupas tratadas foram significativamente reduzidas pelo aumento do tempo de exposição ou nível de potência. Os dados obtidos indicaram que o tratamento com plasma de RF pode ser considerado como um suplemento ambientalmente compatível ou alternativo aos outros métodos de controle para o manejo de produtos-pragas armazenados.

Fumigant toxicity of some essential oils against Red Flour Beetles, Tribolium castaneum (Herbst) and its safety to mammals

Abstract Fumigant activities for three essential oils; Garlic oil (Allium sativum L); Chili pepper (Capsicum annuum L.) and Nigella (Nigella sativa L.) were assessed at different concentrations against the adult and 20-days old larval stages of Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) in the laboratory. The accumulative mortality was observed at different exposure periods (3, 5 and 7 days). The residual effect of garlic oil that was the effective oil, on the treated wheat grains was evaluated with respect to histological changes in the liver, kidney, and stomach of rat fed on this treated wheat. The results showed that the mortality rates of treated stages increased with increasing the time of fumigation treatment. Moreover the highest essential oils toxicity at the Median lethal concentration (LC50) values for exposure periods (3, 5 and 7 days) to fumigation were (126, 53, and 47 mg/L air) for adult stage and were (79, 62, and 41 mg/L air) for larval stage, respectively in the case of Garlic oil treatment. While, the lowest essential oils effective was Nigella oil at the Median lethal concentration (LC50) values for exposure periods (3, 5 and 7 days) to fumigation were (3594, 629, and 335 mg/L air) for adult stage and were (1040, 416, and 227 mg/L air) for larval stage, respectively. The toxicity effect of various essential oils against adults and larvae of T. castaneum at the LC50at 7 days fumigation could be arranged in descending order as follows: Garlic oil, Chili pepper oil, and Nigella oil. The histological changes showed that the organs slightly affected at the fumigation for 3 days. It may be concluded that the garlic essential oil is the good effective fumigant to control T. castaneum in the stored products and it recommended that the fumigation period does not exceed 3 days. The garlic essential oil has the potential for applications in IPM programs for stored-grain pests because of its high volatility and fumigant activity and its safety.

Resumo Atividades fumigantes de três óleos essenciais - óleo de alho (Allium sativum L.); pimenta-malagueta (Capsicum annuum L.) e Nigella (Nigella sativa L.) - foram avaliadas em diferentes concentrações contra adultos e larvas de Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) com 20 dias de idade em laboratório. A mortalidade acumulada foi observada em diferentes períodos de exposição (3, 5 e 7 dias). O efeito residual do óleo de alho, ou seja, o óleo eficaz, nos grãos de trigo tratados foi avaliado em relação às alterações histológicas no fígado, rim e estômago de ratos alimentados com esse trigo tratado. Os resultados mostraram que as taxas de mortalidade dos estágios tratados cresceram com o aumento do tempo de exposição ao tratamento de fumigação. A maior toxidade dos óleos essenciais nos valores de Concentração Letal Média (CL50) para os períodos de exposição (3, 5 e 7 dias) à fumigação foi (126, 53 e 47 mg/L ar) para a fase adulta e (79, 62 e 41 mg/L ar) para a fase de larva, respectivamente no caso do tratamento com o óleo de alho, enquanto que o óleo essencial menos eficaze foi o óleo de Nigella, com valores de CL50 para os períodos de exposição (3, 5 e 7 dias) à fumigação (3594, 629 e 335 mg/L ar) para a fase adulta, e (1040, 416 e 227 mg/L ar) para a fase de larva, respectivamente. O efeito da toxidade de vários óleos essenciais contra adultos e larvas de T. castaneum em LC50 aos sete dias de fumigação pôde ser organizado em ordem decrescente, como segue: óleo de alho, óleo de pimenta e óleo de Nigella. As alterações histológicas mostraram que os órgãos foram levemente afetados na fumigação por três dias. Pode-se concluir que o óleo essencial de alho é um bom fumigante efetivo no controle de T. castaneum nos produtos armazenados, e recomendou-se que o período de fumigação não ultrapassasse três dias. O óleo essencial de alho tem potencial para aplicações em programas de Integrated Pests Management (IPM) para pragas de grãos armazenados, devido à sua alta volatilidade, atividade fumigante e respectiva segurança.