Two sulfonylurea herbicides, metsulfuron methyl （Ally 20 WP） and chlorimuron ethyl （Classic 25 WP） were evaluated for their dissipation bchaviour in alluvial, coastal saline and laterite soils under laboratory inc...Two sulfonylurea herbicides, metsulfuron methyl （Ally 20 WP） and chlorimuron ethyl （Classic 25 WP） were evaluated for their dissipation bchaviour in alluvial, coastal saline and laterite soils under laboratory incubated condition at 60% water holding capacity of soils and 30 ℃ temperature was maintained. In field study herbicides were applied twice for the control of grasses, annual and perennials broad leaves weeds and sedges in rice, wheat and soybean to find out the residual fate of both the herbicides on different matrices of respective crops after harvest. Extraction and clean up methodologies for the herbicides were standardized and subsequently analyzed by HPLC. The study revealed that the half-lives of metsulfuron methyl and chlorimuron ethyl ranged from 10.75 to 13.94 d irrespective of soils and doses applied. Field trials with rice, wheat and soybean also revealed that these two herbicides could safely be recommended for application as no residues were detected in the harvest samples.展开更多
A yeast strain which was capable of degrading sulfonylurea herbicide chlorimuron-ethyl named as LF1 was isolated from a chlorimuron-ethyl contaminated soil near the warehouse of the factory producing chlorimuron-ethyl...A yeast strain which was capable of degrading sulfonylurea herbicide chlorimuron-ethyl named as LF1 was isolated from a chlorimuron-ethyl contaminated soil near the warehouse of the factory producing chlorimuron-ethyl in Shenyang City, Northeast China. The strain was identified as Sporobolomyces sp., based on its morphological and physiological characteristics and the phylogenetic analysis of 18S rRNA gene sequence. So far, this is the only yeast strain of Sporobolomyces sp. which is able to degrade chlorimuronethyl. Incubation tests showed that when the initial concentration of chlorimuron-ethyl in culture was 5 mg/L, LF1 could degrade more than 77% of the herbicide after incubation for 4 d at 30℃. The possible mechanism of chlorimuron-ethyl degradation by LF1 could be the acidic hydrolysis caused by the acids from the metabolism of the yeast strain. Further study should be conducted to examine the pathways of chlorimuron-ethyl degradation by LF1 and to approach the feasibility of using LF1 to degrade the chlorimuron-ethyl in soil system.展开更多
The adsorption-desorption characteristics of chlorimuron-ethyl in soils were investigated to provide the basic data for evaluating the safety in field and the risk to water resource. The adsorption-desorption experime...The adsorption-desorption characteristics of chlorimuron-ethyl in soils were investigated to provide the basic data for evaluating the safety in field and the risk to water resource. The adsorption-desorption experiment was conducted by the batch equilibration and HPLC techniques; furthermore, data were analyzed with 5 mathematic models to describe the characteristics and mechanism of adsorption-desorption and translocation of the herbicide in soils. The results showed that the adsorption-desorption isotherms of chlorimuron-ethyl fitted for the Freundlich model well, and the physical reaction presents the main contribution during the adsorption-desorption process. The adsorption values （Kads-f） of chlorimuron-ethyl in 8 types of soil ranged from 0.798 to 6.891. The isotherms of 2# （Jiangxi clay） and 3# （Jiangxi sand loam） soils belong to the S-type curve, while the isotherms of another 6 type soils belong to the L-type isotherm. The results of desorption indicated that the hysteresis phenomena appeared during the desorption process, and the hysteresis coefficients （H） of the herbicides in 8 soils varied from 0.259-0.980. Furthermore, Kads-f and desorption values （Kads-f） increased with the OM （%） and the clay content increasing, while the values decreased with the soils pH increasing. The H values decreased with the OM and the clay content increasing, and increased with the soils pH increasing. It can be concluded that the low adsorption abilities of chlorimuron-ethyl in test soils and un-reversible adsorption existed in the process, which will induce the great translocation of the herbicide after application in field. It can be transported to ground or groundwater causing risk to environments. The physical and chemical properties of soils, including the OM, the clay content, and the pH of soil were the dominating factors during the adsorption-desorption.展开更多
Effect of chlorimuron-ethyl on biochemical mechanism in tolerant sugar beet was investigated to provide basic data on using the tolerant genotype properly. Tolerant sugar beet was used to analyze its biochemical mecha...Effect of chlorimuron-ethyl on biochemical mechanism in tolerant sugar beet was investigated to provide basic data on using the tolerant genotype properly. Tolerant sugar beet was used to analyze its biochemical mechanism under chlorimuron- ethyl stress with frame culture in field and water culture. Glutathione S-transferase （GST） activity of leaves in tolerant sugar beet was remarkably increased as chlorimuron-ethyl was preemergence applicated at 0.5 and 1.5 g a.i. hw1, at the same time glutathione （GSH） content increased 50.0-490.1 p.g g-~. GST activity of sensitive sugar beet decreased 122.6 U mg-~ min-1 compared with tolerant sugar beet and GSH content only increased to 7.4 p.g g-~ at chlorimuron-ethyl 0.5 g a.i. ha-~ in sensitive sugar beet. The higher GST activity and GSH content conjugated chlorimuron-ethyl absorbed in tolerant sugar beet and made it lost activity. Acetolactate synthases （ALS） activity of the tolerant sugar beet increased to 62.5 and 70.6%, respectively in seedling and leaf growth period, at the same time ALS activity of the sensitive variety was decreased to 36.8 and 64.8%, respectively. The rapidly increased GST activity, GSH content, and ALS, the target enzyme activity were the important pathways for enduring chlorimuron-ethyl in tolerant sugar beet.展开更多
A wheat （Triticum aestivurn L.） bioassay method was used for preliminary determination of chlorimuron degradation in soil by EM （effective microorganisms）. Under the conditions of this study, chlorimuron half-life...A wheat （Triticum aestivurn L.） bioassay method was used for preliminary determination of chlorimuron degradation in soil by EM （effective microorganisms）. Under the conditions of this study, chlorimuron half-life was greater than 30-50 days in soil containing different initial concentrations of chlorimuron. After adding EM, chlorimuron degradation half-life ranged from 10-15 days, which was about 15-30 days shorter than without EM. Chlorimuron degradation was not significantly affected by EM populations applied at 50-200 mL·kg^-1. Both monopotassium phosphate and urea enhanced the ability of EM to degrade chlorimuron, but brown sugar had no significant effect.展开更多
The electrochemical oxidation of chlorimuron-ethyl on metry. The electrochemical behaviour of the electrode in a sodium Ti/SnO2-Sb2O5/PbO2 electrode was studied by cyclic voltamsulfate solution and in the mixture solu...The electrochemical oxidation of chlorimuron-ethyl on metry. The electrochemical behaviour of the electrode in a sodium Ti/SnO2-Sb2O5/PbO2 electrode was studied by cyclic voltamsulfate solution and in the mixture solution of sodium sulfate and chlorimuron-ethyl was studied. The experimental results of cyclic voltammetry show that the acidic medium was suitable for the efficient electrochemical oxidation of chlorimuron-ethyl. Some electro-generated reagent was formed in the electrolysis process and chlorimuron-ethyl could be oxidized by the electro-generated reagent. A Ti/SnO2-Sb2O5/PbO2 electrode was used as the anode and the electrolysis experiment was carried out under the optimized conditions. The electrolysis process was monitored by UV-Vis spectrometry and high performance liquid chromatography（HPLC）, and the chemical oxygen demand（COD） was determined by the potassium dichromate method. The mechanism of chlorimuron-ethyl to be oxided was studied primarily by the cyclic voltammetry and UV-Vis spectrometry. The results of electrolysis experiment demonstrate the possibility of the electrode to be used as an anode for the electrochemical treatment of chlorimuron-ethyl contained in waste water.展开更多
文摘Two sulfonylurea herbicides, metsulfuron methyl （Ally 20 WP） and chlorimuron ethyl （Classic 25 WP） were evaluated for their dissipation bchaviour in alluvial, coastal saline and laterite soils under laboratory incubated condition at 60% water holding capacity of soils and 30 ℃ temperature was maintained. In field study herbicides were applied twice for the control of grasses, annual and perennials broad leaves weeds and sedges in rice, wheat and soybean to find out the residual fate of both the herbicides on different matrices of respective crops after harvest. Extraction and clean up methodologies for the herbicides were standardized and subsequently analyzed by HPLC. The study revealed that the half-lives of metsulfuron methyl and chlorimuron ethyl ranged from 10.75 to 13.94 d irrespective of soils and doses applied. Field trials with rice, wheat and soybean also revealed that these two herbicides could safely be recommended for application as no residues were detected in the harvest samples.
基金supported by the National Natural Science Foundation of China(No.30770405)the Knowledge Innovation Project of the Chinese Academy of Sciences(No.KSCX2-YW-G-053)
文摘A yeast strain which was capable of degrading sulfonylurea herbicide chlorimuron-ethyl named as LF1 was isolated from a chlorimuron-ethyl contaminated soil near the warehouse of the factory producing chlorimuron-ethyl in Shenyang City, Northeast China. The strain was identified as Sporobolomyces sp., based on its morphological and physiological characteristics and the phylogenetic analysis of 18S rRNA gene sequence. So far, this is the only yeast strain of Sporobolomyces sp. which is able to degrade chlorimuronethyl. Incubation tests showed that when the initial concentration of chlorimuron-ethyl in culture was 5 mg/L, LF1 could degrade more than 77% of the herbicide after incubation for 4 d at 30℃. The possible mechanism of chlorimuron-ethyl degradation by LF1 could be the acidic hydrolysis caused by the acids from the metabolism of the yeast strain. Further study should be conducted to examine the pathways of chlorimuron-ethyl degradation by LF1 and to approach the feasibility of using LF1 to degrade the chlorimuron-ethyl in soil system.
文摘The adsorption-desorption characteristics of chlorimuron-ethyl in soils were investigated to provide the basic data for evaluating the safety in field and the risk to water resource. The adsorption-desorption experiment was conducted by the batch equilibration and HPLC techniques; furthermore, data were analyzed with 5 mathematic models to describe the characteristics and mechanism of adsorption-desorption and translocation of the herbicide in soils. The results showed that the adsorption-desorption isotherms of chlorimuron-ethyl fitted for the Freundlich model well, and the physical reaction presents the main contribution during the adsorption-desorption process. The adsorption values （Kads-f） of chlorimuron-ethyl in 8 types of soil ranged from 0.798 to 6.891. The isotherms of 2# （Jiangxi clay） and 3# （Jiangxi sand loam） soils belong to the S-type curve, while the isotherms of another 6 type soils belong to the L-type isotherm. The results of desorption indicated that the hysteresis phenomena appeared during the desorption process, and the hysteresis coefficients （H） of the herbicides in 8 soils varied from 0.259-0.980. Furthermore, Kads-f and desorption values （Kads-f） increased with the OM （%） and the clay content increasing, while the values decreased with the soils pH increasing. The H values decreased with the OM and the clay content increasing, and increased with the soils pH increasing. It can be concluded that the low adsorption abilities of chlorimuron-ethyl in test soils and un-reversible adsorption existed in the process, which will induce the great translocation of the herbicide after application in field. It can be transported to ground or groundwater causing risk to environments. The physical and chemical properties of soils, including the OM, the clay content, and the pH of soil were the dominating factors during the adsorption-desorption.
基金funded by the Deaprtment of Education of Heilongjiang Province (11511039),China
文摘Effect of chlorimuron-ethyl on biochemical mechanism in tolerant sugar beet was investigated to provide basic data on using the tolerant genotype properly. Tolerant sugar beet was used to analyze its biochemical mechanism under chlorimuron- ethyl stress with frame culture in field and water culture. Glutathione S-transferase （GST） activity of leaves in tolerant sugar beet was remarkably increased as chlorimuron-ethyl was preemergence applicated at 0.5 and 1.5 g a.i. hw1, at the same time glutathione （GSH） content increased 50.0-490.1 p.g g-~. GST activity of sensitive sugar beet decreased 122.6 U mg-~ min-1 compared with tolerant sugar beet and GSH content only increased to 7.4 p.g g-~ at chlorimuron-ethyl 0.5 g a.i. ha-~ in sensitive sugar beet. The higher GST activity and GSH content conjugated chlorimuron-ethyl absorbed in tolerant sugar beet and made it lost activity. Acetolactate synthases （ALS） activity of the tolerant sugar beet increased to 62.5 and 70.6%, respectively in seedling and leaf growth period, at the same time ALS activity of the sensitive variety was decreased to 36.8 and 64.8%, respectively. The rapidly increased GST activity, GSH content, and ALS, the target enzyme activity were the important pathways for enduring chlorimuron-ethyl in tolerant sugar beet.
基金Supported by the Youth Fund of Heilongjiang Province (QC03C11)
文摘A wheat （Triticum aestivurn L.） bioassay method was used for preliminary determination of chlorimuron degradation in soil by EM （effective microorganisms）. Under the conditions of this study, chlorimuron half-life was greater than 30-50 days in soil containing different initial concentrations of chlorimuron. After adding EM, chlorimuron degradation half-life ranged from 10-15 days, which was about 15-30 days shorter than without EM. Chlorimuron degradation was not significantly affected by EM populations applied at 50-200 mL·kg^-1. Both monopotassium phosphate and urea enhanced the ability of EM to degrade chlorimuron, but brown sugar had no significant effect.
基金Supported by the Science and Technology Foundation of the Education Department of Liaoning Province,China (No.2009A557)
文摘The electrochemical oxidation of chlorimuron-ethyl on metry. The electrochemical behaviour of the electrode in a sodium Ti/SnO2-Sb2O5/PbO2 electrode was studied by cyclic voltamsulfate solution and in the mixture solution of sodium sulfate and chlorimuron-ethyl was studied. The experimental results of cyclic voltammetry show that the acidic medium was suitable for the efficient electrochemical oxidation of chlorimuron-ethyl. Some electro-generated reagent was formed in the electrolysis process and chlorimuron-ethyl could be oxidized by the electro-generated reagent. A Ti/SnO2-Sb2O5/PbO2 electrode was used as the anode and the electrolysis experiment was carried out under the optimized conditions. The electrolysis process was monitored by UV-Vis spectrometry and high performance liquid chromatography（HPLC）, and the chemical oxygen demand（COD） was determined by the potassium dichromate method. The mechanism of chlorimuron-ethyl to be oxided was studied primarily by the cyclic voltammetry and UV-Vis spectrometry. The results of electrolysis experiment demonstrate the possibility of the electrode to be used as an anode for the electrochemical treatment of chlorimuron-ethyl contained in waste water.
