Papers by Keyword: Pesticide

Abstract: The distribution of residual pesticides in soil and rice grain was studied in rice farming area covered in Samchuk district, Suphanburi province, Thailand. The 19 samples of soil and rice grain were collected by random sampling in 2015 covered 7 sub-districts. The residual carbofuran and glyphosate in soil and rice grain was quantitative determined based on standard method. It was found that the concentration of carbofuran was found in the range of ND-0.0512 µg/kg and ND-0.0865 µg/kg for soil and rice grain, respectively. Glyphosate was found in the range of ND-0.2632 µg/kg and ND-0.2244 µg/kg for soil and rice grain, respectively. The residual levels of carbofuran and glyphosate in soil and rice grain depended on a spray period time, their decomposition and their concentration usage. The residual levels of carbofuran and glyphosate did not significantly quantitative correlation between soil and rice grain for this study area.

Abstract: As the human activities increasing, pesticide, oil and heavy metal used widely caused the environmental pollution more and more serious. Therefore, it is very necessary to find the reasonable and efficient method to degrade environmental pollutants. This article summarized the construction of genetic engineering bacteria and its applications in pesticide pollution, oil pollution and heavy metal pollution bioremediation, which has proved to be a hot pot in environmental pollutants bioremediation researching. It also put forward the difficulties in the construction and application of genetic engineering bacteria and developing trend.

Abstract: The removal of pesticides (quintozene, α-BHC, Aldrin and pp′-DDT) by phenyltrimethylammonium bromide (PTMAB) modified montmorillonites(PTMAB-MMT) was investigated. The results showed that these four kinds of pestcides have high affinity with PTMAB-MMT. The composites were characterized by FTIR and XRD. Further, the removal experiments of pesticides in ginseng extracts were carried out. The Ginsenosides were analyzed by high performance liquid chromatography/mass spectrometry showed that the loss of Ginsenosides was less than 4%. It can be concluded that the PTMAB-MMT is a promising material in pesticide pollution treatment

Abstract: Three kinds of Ti/SnO₂ based electrodes were prepared by thermal decomposition method. The surface morphologies were characterized by SEM, the electrochemical properties were investigated by linear scan voltammetry, CV(cyclic voltammetry), constant current electrolysis. The results show that Ti/SnO₂-Ru/SnO₂-Ce electrode exhibits high oxygen evolution potential and excellent performance of hydroxide radical generation. The removal ratio of 5, 7-dimethyl-2-mercapto-1,2,4-triazole pyrimidine as pollutant in simulated wastewater is up to 89.7% and of COD is 40.4%.

Abstract: In order to reveal the composite contaminations characteristic of dimethoate adsorption onto the surficial sediments, the competitive adsorption of dimethoate in pesticide (dimethoate, metalaxyl, atrazine, malathion, and prometryn)/heavy metals (copper, zinc, lead, cadmium and nickel) system is investigated. A 2^10-5 fractional factorial design method at resolution IV and a multiple linear regression adsorption model are used to identify the main effects and interactions of above ten pollutions. The adsorption amount of dimethoate surficial sediments is set as the dependent variable, and the main effects and second-order interactions of ten pollutions are set as independent variables. Thus, a multiple linear regression model of dimethoate adsorption is screened and established. The results of model show that the main effects of Cd, malathion and prometryn performed a significant antagonistic effect (α=0.05) on the adsorption of dimethoate onto the sediment (competitive adsorption effects), and the order is: prometryn (-0.0925) > Cd (-0.0878) > malathion (-0.0827); while heavy metal Zn performed a significant synergy effect on the adsorption of dimethoate. The second-order interaction effects of Zn*prometryne, Pb*atrazine and Pb*atrazine has a significant antagonistic impact on the adsorption of dimethoate in sediments, which is in a sequence of Zn*prometryne (-0.0967) > Pb*atrazine (-0.0945) > Cd*atrazine (-0.0922). Moreover, according to the rate of contributions of main effects and second-order interaction effects in composite contaminations system, we can also estimate and definite the pollution levels of target pollutant.

Abstract: The resolution IV fractional factorial design was used to study the adsorption regularity of Cu coexisted with various pollutions (Zn, Pb, Cd, Ni, atrazine, malathine, et al.) onto the sediment. The study found that the main effect and the second-order interaction effect of ten pollutions concentration had significant influence on the adsorption of Cu on the sediment. The concentration of Cu was the critical factor to the promotion of the absorption capacity of Cu in sediment, the second-order effect played the critical role in restraining the absorption of Cu. The main effect of Cd, and the second-order interaction effect include Cd, had greatly inhibited the absorption of Cu in sediment, and the contribution was over 30%, which meant there was prominent antagonism between Cu and Cd. Fractional factorial design can provide a theoretical basis for the reveal of the adsorption mechanism between the different contaminants in the water environment pollution.

Abstract: Terahertz wave lies between far-infrared and microwave in electromagnetic spectrum with frequency form 0.1 THz to10 THz. Terahertz is believed to be the master technology of electronics and information science, and to be the bridge between micro electronics and macro wavelength. THz has formed a worldwide research climax. This paper introduces the main characters of Terahertz wave, Terahertz time-domain spectroscopy technology and its application researches, especially detailed the researches in pesticide spectra.

Abstract: In order to reveal the combined pollution characteristic of dimethoate adsorption onto the surficial sediments in pesticide (dimethoate, metalaxyl, atrazine, malathion, prometryn)/heavy metals (copper, zinc, lead, cadmium, nickel) composite contamination system, a completely foldover design and confounding design assisted resolution Ⅲ of 2^10-6 fractional factorial design method is used to identify the main effects and interactions of these ten pollution factors. The study found that the main effects of zinc, cadmium, malathion, prometryn have significant effect (α=0.05) to dimethoate adsorption on the sediment, in which zinc and cadmium will significantly antagonism to adsorption of dimethoate, while metalaxyl and prometryn will significantly collaborative to adsorption of dimethoate, and these main effects’ contribution rates are 64.4% and the second-order interaction effects’ contributions are 35.6%. According to the effect estimates of main effects and second-order interaction effects, zinc*prometryn and cadmium*atrazine have significantly antagonism to adsorption of dimethoate. Moreover, we also can estimate the compound pollution levels about the target pollutant on these main effects and second-order interaction effects of pollutant factors.

Abstract: Lignosulfonate (LS) is an important dispersant for wettable powder (WP). Though domestic products of lignosulfonate in China are very cheap compared to imported products, their performance is often inferior. Two modified products GCL4-1 and GCL4-A, from sodium lignosulfonate and alkali lignin respectively, were developed and their dispersive effects on the performance of 40% myclobutanil wettable powder (WP) were studied compared with the imported product Borresperse Na and the domestic product SXMN. Results show that GCL4-1 and GCL4-A have superior performance in these properties: suspensibility, wettability, surface tension, contact angle and solution retention. GCL4-A was found to be a suitable dispersant for the wettable powder pesticide for it has the best performance per unit price.

Abstract: Resin was synthesized by microwave irradiation. The effects of cross-linker dose， initiator dose, and dispersant dose , as well as synthesis reaction temperature on the synthesized resin adsorption of oil were investigated. Morphologies and textural properties of the synthesized resins were characterized by using Scanning Electron Microscopy (SEM). The results showed: In comparison with synthesis method of traditional water-bath heating, the use of microwave irradiation can make the synthesis time shorter, and 10% increase in oil capacity than traditional water-bath heating. The resin had release function, so it can be made wettable powder or granules, which provided another alternative to cream formulations new way.