[Objective] The aim was to research the residue decline and final residue of acetochlor in rice.[Method] By carrying out crop field trials in 3 places including Heilongjiang,Jilin and Hunan during two years and applyi...[Objective] The aim was to research the residue decline and final residue of acetochlor in rice.[Method] By carrying out crop field trials in 3 places including Heilongjiang,Jilin and Hunan during two years and applying GC technique,the residue decline of acetochlor in rice was analyzed and its final residue was determined.[Result] The half-life of acetochlor in rice was 4.4-8.3 d,being relatively short,and it belonged to easily degradable pesticide.Under dosage condition with effective components of 600 and 900 g/hm2,after application for one time,the determined acetochlor residues in rice were lower than 0.01 mg/kg.[Conclusion] Take multiple factors into consideration,according to the treatment with application dosage of 900 g/hm2,it was suggested that the MRL value of acetochlor in rice should be ascertained as 0.02 mg/kg temporarily and acetochlor should be applied for one time.展开更多
In this study, the effects of acetochlor on the growth of 16 rice varieties were investigated. In addition, the sensitivity of different rice variety to acetochlor and the relationship between sensitivity and variety ...In this study, the effects of acetochlor on the growth of 16 rice varieties were investigated. In addition, the sensitivity of different rice variety to acetochlor and the relationship between sensitivity and variety type were also studied. The effects of acetochlor on the germination of rice were determined in Petri dishes. The inhibitory effects of acetochlor on the seedling height, root length, seedling weight, root weight and other indicators of rice varieties were determined by agar method. The result showed the acetochlor had a certain inhibitory effect on the germination of rice. The low-concentration acetochlor would increase the seedling height and root number. However, when the concentration of acetochlor reached a certain value, its inhibitory effects became obvious. The inhibitory effect of acetochlor on rice roots was stronger than that on rice stems. Among the rice varieties, Sidao had the highest acetochlor tolerance, and Tianyou 3301 had the highest sensitivity to acetochlor. The average inhibition rates of seedling height, fresh seeding weight, root length, fresh plant weight and root number of Sidao in agar culture medium with 0.02 mg/L of acetochlor were 1.46%, 6.42%, 51.06%, 60.87% and -6.45%, respectively, while of Tianyou 3301 were 21.62%, 22.62%, 63.16%, 74.76% and 3.89%, respectively. The sensitivity to acetochlor differed significantly among different rice variety. However, this difference had no significant relationship with variety type.展开更多
Acetochlor and methamidophos are two important agrochemicals which are widely applied to agricultural production in northeast China. The investigation on the earthworm Eisenia fetida as an important type of soil anima...Acetochlor and methamidophos are two important agrochemicals which are widely applied to agricultural production in northeast China. The investigation on the earthworm Eisenia fetida as an important type of soil animals exposed to single and binary-combined contamination of acetochlor and methamidophos was thus carried out. The single toxic effect test showed that the two agrochemicals had their toxicity to the earthworms living in phaiozem. Acetochlor had a stronger acute toxic effect on the earthworms than methamidophos. The mortality of the earthworms exposed to individual acetochlor and methamidophos changed with an increase in the exposure time and the exposed concentrations. The LD50 value of acetochlor and methamidophos toxic to the earthworms was 115.6-275,3 and 29.5-228.6 mg/kg, respectively. The weight of the earthworms was a more sensitive index compared to the mortality in indicating toxic effects of acetochlor and methamidophos in phaiozem. When considering both the mortality and the body-weight change, the combined pollution of acetochlor and methamidophos in phaiozem resulted in their synergic toxic effects on the earthworms.展开更多
In order to evaluate ecological risk of agrochemicals in agricultural environment, single and joint toxic effects of an important herbicide and a typical heavy metal on root elongation of crops were investigated. Seed...In order to evaluate ecological risk of agrochemicals in agricultural environment, single and joint toxic effects of an important herbicide and a typical heavy metal on root elongation of crops were investigated. Seeds of the three crops including wheat （Triticum aestivum）, Chinese cabbage （Brassica pekimensis） and soybean （Glycine max） as the main crops in northeast China were exposed to acetochior as a herbicide and lead （Pb） as a heavy metal using the pot-culture method, and meadow brown soil as one of the main soils distributed in northeast China was applied in the investigation. The results indicated that the interactive effects of the two pollutants on root elongation of the three crops were very complicated although they had markedly significant （P〈0.01） linear interrelationships based on the regression analyses. When the concentration of added Pb^2＋ reached 200 mg/kg, acetochlor and Pb had an antagonistic effect on the inhibition of root elongation of the three crops. However, acetochlor and Pb had significantly （P〈0.05） synergic effects on the inhibition of root elongation when concentration of added Pb^2＋ was up to 1000 mg/kg. At the low concentration of added Pb, joint toxicity of acetochlor and Pb was more dependent on the concentration of Pb. Among the three crops, wheat was the most sensitive to the toxicity of Pb and Chinese cabbage was the most sensitive to the toxicity of acetochlor.展开更多
The biodegradation of two acetanilide herbicides, acetochlor and butachlor in soil after other environmental organic matters addition were measured during 35 days laboratory incubations. The herbicides were applied to...The biodegradation of two acetanilide herbicides, acetochlor and butachlor in soil after other environmental organic matters addition were measured during 35 days laboratory incubations. The herbicides were applied to soil alone, soil SDBS (sodium dodecylbenzene sulfonate) mixtures and soil HA (humic acid) mixtures. Herbicide biodegradation kinetics were compared in the different treatment. Biodegradation products of herbicides in soil alone samples were identified by GC/MS at the end of incubation. Addition of SDBS and HA to soil decreased acetochlor biodegradation, but increased butachlor biodegradation. The biodegradation half life of acetochlor and butachlor in soil alone, soil SDBS mixtures and soil HA mixtures were 4.6d, 6.1d and 5.4d and 5.3d, 4.9d and 5.3d respectively. The biodegradation products were hydroxyacetochlor and 2 methyl 6 ethylaniline for acetochlor, and hydroxybutachlor and 2,6 diethylaniline for butachlor.展开更多
Toxic effects of two agrochemicals on nifH gene in agricultural black soil were investigated using denaturing gradient gel electrophoresis （DGGE） and sequencing approaches in a microcosm experiment. Changes of soil ...Toxic effects of two agrochemicals on nifH gene in agricultural black soil were investigated using denaturing gradient gel electrophoresis （DGGE） and sequencing approaches in a microcosm experiment. Changes of soil nifH gene diversity and composition were examined following the application of acetochlor, methamidophos and their combination. Acetochlor reduced the nifH gene diversity （both in gene richness and diversity index values） and caused changes in the nifH gene composition. The effects of acetochlor on nifH gene were strengthened as the concentration of acetochlor increased. Cluster analysis of DGGE banding patterns showed that nifH gene composition which had been affected by low concentration of acetochlor （50 mg/kg） recovered firstly. Methamidophos reduced nifH gene richness that except at 4 weeks. The medium concentration of methamidophos （150 mg/kg） caused the most apparent changes in nifH gene diversity at the first week while the high concentration of methamidophos （250 mg/kg） produced prominent effects on nifH gene diversity in the following weeks. Cluster analysis showed that minimal changes of nifH gene composition were found at 1 week and maximal changes at 4 weeks. Toxic effects of acetochlor and methamidophos combination on nifH gene were also apparent. Different nifH genes （bands） responded differently to the impact of agrochemicals： four individual bands were eliminated by the application of the agrochemicals, five bands became predominant by the stimulation of the agrochemicals, and four bands showed strong resistance to the influence of the agrochemicals. Fifteen prominent bands were partially sequenced, yielding 15 different nifH sequences, which were used for phylogenetic reconstructions. All sequences were affiliated with the alpha- and beta-proteobacteria, showing higher similarity to eight different diazotrophic genera.展开更多
The behavior of herbicide acetochlor adsorption desorption to soil in the presence of humic acid (HA), anionic surfactant sodium dodecylbenzene sulfonate (SDBS), cationic surfactant hexadecyltrimethyl ammonium bromi...The behavior of herbicide acetochlor adsorption desorption to soil in the presence of humic acid (HA), anionic surfactant sodium dodecylbenzene sulfonate (SDBS), cationic surfactant hexadecyltrimethyl ammonium bromide (HDAB) and NH 4NO 3 as a chemical fertilizer was studied. Observed acetochlor adsorption isotherm were well described using Freundlich isotherm equation, from which the desorption isotherm equation has been deduced. The deduced equation can more directly describe acetochlor desorption process. The results showed that the enhance of acetochlor adsorption capacity by solid HA was greater than by soluble HA. The presence of NH 4NO 3 can slightly enhance acetochlor adsorption to soil by comparison with that measured in NH 4NO 3 free solution. In soil water system, surfactant acetochlor interaction is very complex, and the surfactant adsorptions as well as acetochlor adsorption need to be considered. When acetochlor soil suspensions contained lower concentration SDBS or HDAB (40 mg/L), K f for acetochlor adsorption was decreased in comparison to that measured in SDBS or HDAB free solution. When acetochlor soil suspensions contained higher concentration SDBS or HDAB (corresponding 1400 mg/L or 200 mg/L), K f for acetochlor adsorption was increased in comparison to that measured in SDBS or HDAB free solution.展开更多
The Songhua River Basin is a burgeoning agricultural area in the modern times in China. Particularly in recent years, increasing chemical fertilizers and pesticides have been applied with the development of agricultur...The Songhua River Basin is a burgeoning agricultural area in the modern times in China. Particularly in recent years, increasing chemical fertilizers and pesticides have been applied with the development of agricultural production. However, the situation of non- point source pollution （NSP） from agricultural production in this basin is still obscure. In order to solve the problem, the occurrence and distribution of acetochlor in sediments and riparian soils of the Songhua River Basin before rain season and after rain season were investigated. In addition, total organic carbon was analyzed. The result showed that the concentration of acetochlor ranged from 0.47 to 11.76 μg/kg in sediments and 0.03 to 709.37 μg/kg in riparian soils. During the high flow period in 2009, the mean concentration was 4.79 μg/kg in sediments and 0.75 μg]kg in riparian soils, respectively. Similarly, the mean concentration was 2.53 μg/kg in sediments and 61.36μg/kg in riparian soils, during the average flow period in 2010. There was a significant correlation between the concentration of acetochlor and total organic carbon in surface sediments. Moreover, the distribution of acetochlor in sediments of the Songhua River was significantly correlated to land use and topography of the watershed. The investigated data suggested that the concentration of acetochlor in the Songnen Plain and the Sanjiang Plain was higher than that in the other areas of the basin, and riparian buffering zones in these areas bad been destroyed by human activities. The optimal agricultural measures to alleviate the contamination of pesticides should be adopted, including controlling agricultural application of acetochlor and ecological restoration of riparian buffering strips.展开更多
Acetochlor is an increasingly used herbicide on corn in North China. Currently, the effect of acetochlor on soil ammonia-oxidizing bacteria (AOB) communities is not well documented. Here, we studied the diversity and ...Acetochlor is an increasingly used herbicide on corn in North China. Currently, the effect of acetochlor on soil ammonia-oxidizing bacteria (AOB) communities is not well documented. Here, we studied the diversity and community composition of AOB in soil amended with three concentrations of acetochlor (50, 150, 250 mg/kg) and the control (0 mg acetochlor/kg soil) in a microcosm experiment by PCR-DGGE (polymerase chain reaction-denaturing gradient gel electrophoresis) and the phylogenetic analysis of excised ...展开更多
The sunlight photodegradation half-lives of 20 mg/L acetochlor were 151, 154 and 169 days in de-ionized water, river water and paddy water, respectively. When exposed to ultraviolet (UV) light, acetochlor in aqueous s...The sunlight photodegradation half-lives of 20 mg/L acetochlor were 151, 154 and 169 days in de-ionized water, river water and paddy water, respectively. When exposed to ultraviolet (UV) light, acetochlor in aqueous solution was rapidly degraded. The half-lives were 7.1, 10.1, and 11.5 min in de-ionized water, river water and paddy water, respectively. Photoproducts of acetochlor were identified by gas chromatography/mass spectrometry(GC/MS) and found at least twelve photoproducts resulted from dechlorination with subsequent hydroxylation and cyclization processes. The chemical structures of ten photoproducts were presumed on the basis of mass spectrum interpretation and literature data. Photoproducts are identified as 2-ethyl-6-methylaniline; N,N-diethylaniline; 4,8-dimethyl-2-oxo-1,2,3,4- tetrahydroquino-line; 2-oxo-N-(2-ethyl-6-methylphenyl)-N-(ethoxymethyl)acetamide; N-(ethoxymethyl)-2′-ethyl-6′-methylformanilide;1-hydroxyacetyl-2-ethoxyl-7-ethylind ole; 8-ethyl-1-ethoxymethyl-2-oxo-1,2,3,4-tetrahydroquinoline; 4,8-dimethyl-1-ethoxymethyl-2-oxo-1,2,3,4-tetrahydroquinoline; 2-hydroxy-2′-ethyl-6′-methyl-N-(ethoxymethyl)acetanilide and a compound related to acetochlor. The other two photoproducts were detected by GC/MS although their chemical structure was unknown.展开更多
The actions and interactions of acetochlor and As on the soil phosphatase activity were investigated after 1, 3, 6, 10, 15, 30 and 60 d of exposure under control conditions. The soils were exposed to various concentra...The actions and interactions of acetochlor and As on the soil phosphatase activity were investigated after 1, 3, 6, 10, 15, 30 and 60 d of exposure under control conditions. The soils were exposed to various concentrations of acetochlor and As individually and simultaneously. The results showed that acetochlor, As only, and combined pollution all clearly inhibited soil phosphatase activity. The maximum inhibition ratios of soil phosphatase activity by acetochlor, As only and combined pollution were 36.44, 74.12 and 61.29%, respectively. Two kinetic models, ν=c/（1＋bi） （model 1） and ν=c（1＋ai）/（l＋bi） （model 2）, were used to describe the relationship between the concentrations of As and acetochlor and the activity of soil phosphatase. The semi-effect dose （ED 50 ） values induced by As and acetochlor stress based on the inhibition of soil phosphatase were 18.1 and 33.11 mg kg-1, respectively, according to calculation by model 1. The interactive effect of acetochlor with As on soil phosphatase primarily consisted of significant antagonism effects at the higher concentrations tested. The step regression results show that the toxicity order was As （III）〉acetochlor〉As （III）×acetochlor throughout the incubation period.展开更多
To assess the sublethal toxicity of the herbicide acetochlor to earthworms and to find out biomarkers possible inducted under acetochlor exposure, Eiseniafetida was exposed to artificial soils supplemented with differ...To assess the sublethal toxicity of the herbicide acetochlor to earthworms and to find out biomarkers possible inducted under acetochlor exposure, Eiseniafetida was exposed to artificial soils supplemented with different concentrations of acetochlor（5, 10, 20, 40 and 80 mg/kg soil）. Effects of the acetochlor on cytochrome P450 monooxygenases p-nitroanisole O-demethylase（ODM）, aldrin epoxidase（AE） and glutathione-S-transferases （GSTs） activities were determined. The results revealed cytochrome P450 monooxygenases were elevated with increasing concentrations of acetochlor, and the AE activity increased significantly compared with control at the concentration of 80 mg/kg （P〈0.05）. However, ODM activity from E. fetida was not induced significantly by acetochlor at all treatments（P〉0.05）. Sodium dodecyl sulfate-polyacryamide gel electrophoresis（SDS-PAGE） showed that one protein band was visualized and no evident differences were found in protein profiles between treatments and control. The GST activity increased significantly with longer duration（P〈0.05） and increasing concentrations of acetochlor exposure（P〈0.05）. This study showed that the monooxygenases and GSTs activities in E. fetida could be induced by acetochlor, and thus, the AE and GST could be used in sublethal assays for soil contamination surveys and GST could be used as biomarkers of acetochlor exposure in E. fetida.展开更多
Acetochlor is a widely used herbicide in agricultural production. Studies have shown that acetochlor has obvious environmental hormone effects, and long-term exposure may pose a threat to human health. To quantify the...Acetochlor is a widely used herbicide in agricultural production. Studies have shown that acetochlor has obvious environmental hormone effects, and long-term exposure may pose a threat to human health. To quantify the hazards of acetochlor in drinking water, a health risk assessment of acetochlor was conducted in major cities of China based on the data of acetochlor residue concentrations in drinking water. The approach of the Species Sensitivity Distributions(SSD) method is used to extrapolate from animal testing data to reflect worst case human toxicity. Results show that hazard quotients related to acetochlor residues in drinking water for different age groups range from 1.94 × 10-4 to 6.13 × 10-4, so, there are no indication of human risk. Compared to the total estimated hazard quotient from oral intake of acetochlor, the chronic exposure imputed to acetochlor residues in drinking water in China accounts for 0.4%. This paper recommends 0.02 mg/L to be the maximum acetochlor residue concentration level in drinking water and source water criteria.展开更多
Using plate counting and ergosterol assay, single and joint effects of acetochlor and methamidophos on the dynamicsof soil fungal population and total fungal biomass in the black soil zone of Northeast China were inve...Using plate counting and ergosterol assay, single and joint effects of acetochlor and methamidophos on the dynamicsof soil fungal population and total fungal biomass in the black soil zone of Northeast China were investigated. The resultsdemonstrated that acetochlor at high concentration levels (150 and 250 mg kg-1) had an acute and mostly chronic toxicityon both the soil fungal population and total fungal biomass, but at a low concentration (50 mg kg-1) generally had astimulating effect that was stronger with total fungal biomass than with the soil fungal population. Methamidophos ata high concentration level (250 mg kg-1) alone and almost all of its combinations with various dosages of acetochlorincreased the soil fungal population, whereas at most sampling dates with 250 mg methamidophos kg-1 soil, total fungalbiomass increased, but in combination with acetochlor it was decreased in the early period of incubation and then increased28 days after incubation. Thus, through measuring the number of colony forming unit of the soil fungal population alongwith the total fungal biomass, a better understanding on effects of agrochemicals on soil fungi could be made.展开更多
This study investigated the bioremediation of organic pollution in soil and water systems by cyanobacterial mats collected from Wadi Gaza. Acetochlor, a model compound of herbicide, was used as a standard organic poll...This study investigated the bioremediation of organic pollution in soil and water systems by cyanobacterial mats collected from Wadi Gaza. Acetochlor, a model compound of herbicide, was used as a standard organic pollutant. Various concentrations of acetochlor were injected in soil and water samples pre-treated with cyanobacterial mat for several periods of time. Percentage of growth of wheat as a test plant was taken as indicator of bioremediation of acetochlor. Results showed that acetochlor was degraded in both soil and water systems. Degradation was?much?faster in the water system than in the soil system. Concentrations of acetochlor above the field rate did not affect the bioremediation process in the water system whereas it did in soil pots. Furthermore, bioremediation in water system was nearly completed in 15 days whereas it did not reach high percentage?in the soil system. These encouraging results are new contribution in field of bioremediation of pesticide by cyanobacterial mats and suggest that application of cyanobacterial mat could be a fast and suitable methodology for bioremediation of organic pollutant in the ecosystem.展开更多
Effects of four kinds of triazine herbicides on the photodegradation of acetochlor were studied on glass surface and in aqueous solution under three kinds of light sources, i.e., xenon lamp, high pressure mercury lamp...Effects of four kinds of triazine herbicides on the photodegradation of acetochlor were studied on glass surface and in aqueous solution under three kinds of light sources, i.e., xenon lamp, high pressure mercury lamp and natural sunlight. The results indicated that atrazine, simetryne, prometryne and ametryne exhibited significant effects on the photoquenching degradation of acetochlor, and there was an obvious positive correlation between their effects and the dosage of four kinds of triazine herbicides.展开更多
Adsorption of phenthoate and acetochlor onto kaolin, montmorillonite, bentonite clays and respective organoclays prepared by the exchange of quaternary ammonium as tetradecyltrimethyl ammonium bromide(TTAB), dodecyltr...Adsorption of phenthoate and acetochlor onto kaolin, montmorillonite, bentonite clays and respective organoclays prepared by the exchange of quaternary ammonium as tetradecyltrimethyl ammonium bromide(TTAB), dodecyltrimethylammonium bromide(DTAB), and cetylpyridinium chloride(CPC) were studied. The adsorption equilibrium data points were fitted to Freundlich isotherm equations. The adsorption of phenthoate and acetochlor were significantly enhanced by surfactant treatment of the clays. The amount of both pesticides adsorbed per unit mass of organoclay followed the order of TTA-kaolin < TTA-montmorillonite < TTA-bentonite, which is inconsistent with the organic carbon content of the clays. The removal efficiency of organomontmorillonite to treat acetochlor is in the order of CP(C 16 )-montmorillonite > TTA(C 14 )-montmorillonite > DTA(C 12 )-montmorillonite. Phenthoate is adsorbed to greater extent than acetochlor by each adsorbent, which may be due to the higher hydrophobicity of phenthoate, indicating considerable hydrophobic interaction between adsorbent/adsorbate systems.展开更多
[Objectives] This study was conducted to investigate the toxic effect of acetochlor in loaches. [Methods]Loaches were put into the acetochlor solution with concentrations of 0,0. 062 5,0. 125,0. 25,0. 5 and 1 μl/L,re...[Objectives] This study was conducted to investigate the toxic effect of acetochlor in loaches. [Methods]Loaches were put into the acetochlor solution with concentrations of 0,0. 062 5,0. 125,0. 25,0. 5 and 1 μl/L,respectively. The effects on dismutase( SOD),peroxidase( POD),catalase( CAT) and glutathione( GSH) activity and malondialdehyde( MDA) content in the liver of loaches were analyzed after 12,24,48 and 72 h of exposure. [Results] The activity of SOD,POD,CAT and GSH increased with the stress time and concentration,reached their maximums at 48 h after acetochlor treatment,and then decreased.However,MDA content increased with the stress time and concentration. [Conclusions] Acetochlor had obvious oxidative stress on loaches,and the activity of SOD,POD,CAT and GSH showed an obvious induction-inhibition effect with the increase of acetochlor concentration and the extension of stress time.展开更多
基金Supported by Pesticide Residue Project in Department of Agriculture(2008F324)~~
文摘[Objective] The aim was to research the residue decline and final residue of acetochlor in rice.[Method] By carrying out crop field trials in 3 places including Heilongjiang,Jilin and Hunan during two years and applying GC technique,the residue decline of acetochlor in rice was analyzed and its final residue was determined.[Result] The half-life of acetochlor in rice was 4.4-8.3 d,being relatively short,and it belonged to easily degradable pesticide.Under dosage condition with effective components of 600 and 900 g/hm2,after application for one time,the determined acetochlor residues in rice were lower than 0.01 mg/kg.[Conclusion] Take multiple factors into consideration,according to the treatment with application dosage of 900 g/hm2,it was suggested that the MRL value of acetochlor in rice should be ascertained as 0.02 mg/kg temporarily and acetochlor should be applied for one time.
基金Supported by Graduate Research and Innovation Projects in Hunan Province(CX2013B418)Industrialization Cultivation Projects in Colleges and Universities of Hunan Province(13CY030)~~
文摘In this study, the effects of acetochlor on the growth of 16 rice varieties were investigated. In addition, the sensitivity of different rice variety to acetochlor and the relationship between sensitivity and variety type were also studied. The effects of acetochlor on the germination of rice were determined in Petri dishes. The inhibitory effects of acetochlor on the seedling height, root length, seedling weight, root weight and other indicators of rice varieties were determined by agar method. The result showed the acetochlor had a certain inhibitory effect on the germination of rice. The low-concentration acetochlor would increase the seedling height and root number. However, when the concentration of acetochlor reached a certain value, its inhibitory effects became obvious. The inhibitory effect of acetochlor on rice roots was stronger than that on rice stems. Among the rice varieties, Sidao had the highest acetochlor tolerance, and Tianyou 3301 had the highest sensitivity to acetochlor. The average inhibition rates of seedling height, fresh seeding weight, root length, fresh plant weight and root number of Sidao in agar culture medium with 0.02 mg/L of acetochlor were 1.46%, 6.42%, 51.06%, 60.87% and -6.45%, respectively, while of Tianyou 3301 were 21.62%, 22.62%, 63.16%, 74.76% and 3.89%, respectively. The sensitivity to acetochlor differed significantly among different rice variety. However, this difference had no significant relationship with variety type.
文摘Acetochlor and methamidophos are two important agrochemicals which are widely applied to agricultural production in northeast China. The investigation on the earthworm Eisenia fetida as an important type of soil animals exposed to single and binary-combined contamination of acetochlor and methamidophos was thus carried out. The single toxic effect test showed that the two agrochemicals had their toxicity to the earthworms living in phaiozem. Acetochlor had a stronger acute toxic effect on the earthworms than methamidophos. The mortality of the earthworms exposed to individual acetochlor and methamidophos changed with an increase in the exposure time and the exposed concentrations. The LD50 value of acetochlor and methamidophos toxic to the earthworms was 115.6-275,3 and 29.5-228.6 mg/kg, respectively. The weight of the earthworms was a more sensitive index compared to the mortality in indicating toxic effects of acetochlor and methamidophos in phaiozem. When considering both the mortality and the body-weight change, the combined pollution of acetochlor and methamidophos in phaiozem resulted in their synergic toxic effects on the earthworms.
基金Project supported by the National Science Fund for Distinguished Young Scholar of China(No.20225722)the National Natural Science Founda-tion of China(No.20337010)the National Basic Research Program (973)of China(No.2004CB418503).
文摘In order to evaluate ecological risk of agrochemicals in agricultural environment, single and joint toxic effects of an important herbicide and a typical heavy metal on root elongation of crops were investigated. Seeds of the three crops including wheat （Triticum aestivum）, Chinese cabbage （Brassica pekimensis） and soybean （Glycine max） as the main crops in northeast China were exposed to acetochior as a herbicide and lead （Pb） as a heavy metal using the pot-culture method, and meadow brown soil as one of the main soils distributed in northeast China was applied in the investigation. The results indicated that the interactive effects of the two pollutants on root elongation of the three crops were very complicated although they had markedly significant （P〈0.01） linear interrelationships based on the regression analyses. When the concentration of added Pb^2＋ reached 200 mg/kg, acetochlor and Pb had an antagonistic effect on the inhibition of root elongation of the three crops. However, acetochlor and Pb had significantly （P〈0.05） synergic effects on the inhibition of root elongation when concentration of added Pb^2＋ was up to 1000 mg/kg. At the low concentration of added Pb, joint toxicity of acetochlor and Pb was more dependent on the concentration of Pb. Among the three crops, wheat was the most sensitive to the toxicity of Pb and Chinese cabbage was the most sensitive to the toxicity of acetochlor.
基金TheNationalNaturalScienceFoundationofChina (No .2 98371 70 )
文摘The biodegradation of two acetanilide herbicides, acetochlor and butachlor in soil after other environmental organic matters addition were measured during 35 days laboratory incubations. The herbicides were applied to soil alone, soil SDBS (sodium dodecylbenzene sulfonate) mixtures and soil HA (humic acid) mixtures. Herbicide biodegradation kinetics were compared in the different treatment. Biodegradation products of herbicides in soil alone samples were identified by GC/MS at the end of incubation. Addition of SDBS and HA to soil decreased acetochlor biodegradation, but increased butachlor biodegradation. The biodegradation half life of acetochlor and butachlor in soil alone, soil SDBS mixtures and soil HA mixtures were 4.6d, 6.1d and 5.4d and 5.3d, 4.9d and 5.3d respectively. The biodegradation products were hydroxyacetochlor and 2 methyl 6 ethylaniline for acetochlor, and hydroxybutachlor and 2,6 diethylaniline for butachlor.
基金Preject supported by the National Basic Research Program (973) of China(No. 2004CB418503)the Overseas Fund of Institute of AppliedEcology, Chinese Academy of Sciences.
文摘Toxic effects of two agrochemicals on nifH gene in agricultural black soil were investigated using denaturing gradient gel electrophoresis （DGGE） and sequencing approaches in a microcosm experiment. Changes of soil nifH gene diversity and composition were examined following the application of acetochlor, methamidophos and their combination. Acetochlor reduced the nifH gene diversity （both in gene richness and diversity index values） and caused changes in the nifH gene composition. The effects of acetochlor on nifH gene were strengthened as the concentration of acetochlor increased. Cluster analysis of DGGE banding patterns showed that nifH gene composition which had been affected by low concentration of acetochlor （50 mg/kg） recovered firstly. Methamidophos reduced nifH gene richness that except at 4 weeks. The medium concentration of methamidophos （150 mg/kg） caused the most apparent changes in nifH gene diversity at the first week while the high concentration of methamidophos （250 mg/kg） produced prominent effects on nifH gene diversity in the following weeks. Cluster analysis showed that minimal changes of nifH gene composition were found at 1 week and maximal changes at 4 weeks. Toxic effects of acetochlor and methamidophos combination on nifH gene were also apparent. Different nifH genes （bands） responded differently to the impact of agrochemicals： four individual bands were eliminated by the application of the agrochemicals, five bands became predominant by the stimulation of the agrochemicals, and four bands showed strong resistance to the influence of the agrochemicals. Fifteen prominent bands were partially sequenced, yielding 15 different nifH sequences, which were used for phylogenetic reconstructions. All sequences were affiliated with the alpha- and beta-proteobacteria, showing higher similarity to eight different diazotrophic genera.
文摘The behavior of herbicide acetochlor adsorption desorption to soil in the presence of humic acid (HA), anionic surfactant sodium dodecylbenzene sulfonate (SDBS), cationic surfactant hexadecyltrimethyl ammonium bromide (HDAB) and NH 4NO 3 as a chemical fertilizer was studied. Observed acetochlor adsorption isotherm were well described using Freundlich isotherm equation, from which the desorption isotherm equation has been deduced. The deduced equation can more directly describe acetochlor desorption process. The results showed that the enhance of acetochlor adsorption capacity by solid HA was greater than by soluble HA. The presence of NH 4NO 3 can slightly enhance acetochlor adsorption to soil by comparison with that measured in NH 4NO 3 free solution. In soil water system, surfactant acetochlor interaction is very complex, and the surfactant adsorptions as well as acetochlor adsorption need to be considered. When acetochlor soil suspensions contained lower concentration SDBS or HDAB (40 mg/L), K f for acetochlor adsorption was decreased in comparison to that measured in SDBS or HDAB free solution. When acetochlor soil suspensions contained higher concentration SDBS or HDAB (corresponding 1400 mg/L or 200 mg/L), K f for acetochlor adsorption was increased in comparison to that measured in SDBS or HDAB free solution.
基金supported by the National Special Water Project in China (No. 2008ZX07526-002-01)
文摘The Songhua River Basin is a burgeoning agricultural area in the modern times in China. Particularly in recent years, increasing chemical fertilizers and pesticides have been applied with the development of agricultural production. However, the situation of non- point source pollution （NSP） from agricultural production in this basin is still obscure. In order to solve the problem, the occurrence and distribution of acetochlor in sediments and riparian soils of the Songhua River Basin before rain season and after rain season were investigated. In addition, total organic carbon was analyzed. The result showed that the concentration of acetochlor ranged from 0.47 to 11.76 μg/kg in sediments and 0.03 to 709.37 μg/kg in riparian soils. During the high flow period in 2009, the mean concentration was 4.79 μg/kg in sediments and 0.75 μg]kg in riparian soils, respectively. Similarly, the mean concentration was 2.53 μg/kg in sediments and 61.36μg/kg in riparian soils, during the average flow period in 2010. There was a significant correlation between the concentration of acetochlor and total organic carbon in surface sediments. Moreover, the distribution of acetochlor in sediments of the Songhua River was significantly correlated to land use and topography of the watershed. The investigated data suggested that the concentration of acetochlor in the Songnen Plain and the Sanjiang Plain was higher than that in the other areas of the basin, and riparian buffering zones in these areas bad been destroyed by human activities. The optimal agricultural measures to alleviate the contamination of pesticides should be adopted, including controlling agricultural application of acetochlor and ecological restoration of riparian buffering strips.
基金the Natural Science Foun-dation for Young Scientists of China (No. 40701088)
文摘Acetochlor is an increasingly used herbicide on corn in North China. Currently, the effect of acetochlor on soil ammonia-oxidizing bacteria (AOB) communities is not well documented. Here, we studied the diversity and community composition of AOB in soil amended with three concentrations of acetochlor (50, 150, 250 mg/kg) and the control (0 mg acetochlor/kg soil) in a microcosm experiment by PCR-DGGE (polymerase chain reaction-denaturing gradient gel electrophoresis) and the phylogenetic analysis of excised ...
文摘The sunlight photodegradation half-lives of 20 mg/L acetochlor were 151, 154 and 169 days in de-ionized water, river water and paddy water, respectively. When exposed to ultraviolet (UV) light, acetochlor in aqueous solution was rapidly degraded. The half-lives were 7.1, 10.1, and 11.5 min in de-ionized water, river water and paddy water, respectively. Photoproducts of acetochlor were identified by gas chromatography/mass spectrometry(GC/MS) and found at least twelve photoproducts resulted from dechlorination with subsequent hydroxylation and cyclization processes. The chemical structures of ten photoproducts were presumed on the basis of mass spectrum interpretation and literature data. Photoproducts are identified as 2-ethyl-6-methylaniline; N,N-diethylaniline; 4,8-dimethyl-2-oxo-1,2,3,4- tetrahydroquino-line; 2-oxo-N-(2-ethyl-6-methylphenyl)-N-(ethoxymethyl)acetamide; N-(ethoxymethyl)-2′-ethyl-6′-methylformanilide;1-hydroxyacetyl-2-ethoxyl-7-ethylind ole; 8-ethyl-1-ethoxymethyl-2-oxo-1,2,3,4-tetrahydroquinoline; 4,8-dimethyl-1-ethoxymethyl-2-oxo-1,2,3,4-tetrahydroquinoline; 2-hydroxy-2′-ethyl-6′-methyl-N-(ethoxymethyl)acetanilide and a compound related to acetochlor. The other two photoproducts were detected by GC/MS although their chemical structure was unknown.
基金supported by the National Natural Science Foundation of China(41101455)
文摘The actions and interactions of acetochlor and As on the soil phosphatase activity were investigated after 1, 3, 6, 10, 15, 30 and 60 d of exposure under control conditions. The soils were exposed to various concentrations of acetochlor and As individually and simultaneously. The results showed that acetochlor, As only, and combined pollution all clearly inhibited soil phosphatase activity. The maximum inhibition ratios of soil phosphatase activity by acetochlor, As only and combined pollution were 36.44, 74.12 and 61.29%, respectively. Two kinetic models, ν=c/（1＋bi） （model 1） and ν=c（1＋ai）/（l＋bi） （model 2）, were used to describe the relationship between the concentrations of As and acetochlor and the activity of soil phosphatase. The semi-effect dose （ED 50 ） values induced by As and acetochlor stress based on the inhibition of soil phosphatase were 18.1 and 33.11 mg kg-1, respectively, according to calculation by model 1. The interactive effect of acetochlor with As on soil phosphatase primarily consisted of significant antagonism effects at the higher concentrations tested. The step regression results show that the toxicity order was As （III）〉acetochlor〉As （III）×acetochlor throughout the incubation period.
文摘To assess the sublethal toxicity of the herbicide acetochlor to earthworms and to find out biomarkers possible inducted under acetochlor exposure, Eiseniafetida was exposed to artificial soils supplemented with different concentrations of acetochlor（5, 10, 20, 40 and 80 mg/kg soil）. Effects of the acetochlor on cytochrome P450 monooxygenases p-nitroanisole O-demethylase（ODM）, aldrin epoxidase（AE） and glutathione-S-transferases （GSTs） activities were determined. The results revealed cytochrome P450 monooxygenases were elevated with increasing concentrations of acetochlor, and the AE activity increased significantly compared with control at the concentration of 80 mg/kg （P〈0.05）. However, ODM activity from E. fetida was not induced significantly by acetochlor at all treatments（P〉0.05）. Sodium dodecyl sulfate-polyacryamide gel electrophoresis（SDS-PAGE） showed that one protein band was visualized and no evident differences were found in protein profiles between treatments and control. The GST activity increased significantly with longer duration（P〈0.05） and increasing concentrations of acetochlor exposure（P〈0.05）. This study showed that the monooxygenases and GSTs activities in E. fetida could be induced by acetochlor, and thus, the AE and GST could be used in sublethal assays for soil contamination surveys and GST could be used as biomarkers of acetochlor exposure in E. fetida.
基金supported by the Foundation of Major Science and Technology Program for Water Pollution Control and Treatment (No. 2018ZX07502001)the National Natural Science Foundation of China (Nos. 21976205, 21477158 and 11771241)。
文摘Acetochlor is a widely used herbicide in agricultural production. Studies have shown that acetochlor has obvious environmental hormone effects, and long-term exposure may pose a threat to human health. To quantify the hazards of acetochlor in drinking water, a health risk assessment of acetochlor was conducted in major cities of China based on the data of acetochlor residue concentrations in drinking water. The approach of the Species Sensitivity Distributions(SSD) method is used to extrapolate from animal testing data to reflect worst case human toxicity. Results show that hazard quotients related to acetochlor residues in drinking water for different age groups range from 1.94 × 10-4 to 6.13 × 10-4, so, there are no indication of human risk. Compared to the total estimated hazard quotient from oral intake of acetochlor, the chronic exposure imputed to acetochlor residues in drinking water in China accounts for 0.4%. This paper recommends 0.02 mg/L to be the maximum acetochlor residue concentration level in drinking water and source water criteria.
基金the National Key Basic Research Support Foundation of China (No. 2004CB418503), the NationalScience Fund for Distinguished Young Scholars (No. 20225722) and the Innovation Project of the Institute of AppliedEcology, Chinese Academy of Sciences (No. C12SFSLYQY0402).
文摘Using plate counting and ergosterol assay, single and joint effects of acetochlor and methamidophos on the dynamicsof soil fungal population and total fungal biomass in the black soil zone of Northeast China were investigated. The resultsdemonstrated that acetochlor at high concentration levels (150 and 250 mg kg-1) had an acute and mostly chronic toxicityon both the soil fungal population and total fungal biomass, but at a low concentration (50 mg kg-1) generally had astimulating effect that was stronger with total fungal biomass than with the soil fungal population. Methamidophos ata high concentration level (250 mg kg-1) alone and almost all of its combinations with various dosages of acetochlorincreased the soil fungal population, whereas at most sampling dates with 250 mg methamidophos kg-1 soil, total fungalbiomass increased, but in combination with acetochlor it was decreased in the early period of incubation and then increased28 days after incubation. Thus, through measuring the number of colony forming unit of the soil fungal population alongwith the total fungal biomass, a better understanding on effects of agrochemicals on soil fungi could be made.
文摘This study investigated the bioremediation of organic pollution in soil and water systems by cyanobacterial mats collected from Wadi Gaza. Acetochlor, a model compound of herbicide, was used as a standard organic pollutant. Various concentrations of acetochlor were injected in soil and water samples pre-treated with cyanobacterial mat for several periods of time. Percentage of growth of wheat as a test plant was taken as indicator of bioremediation of acetochlor. Results showed that acetochlor was degraded in both soil and water systems. Degradation was?much?faster in the water system than in the soil system. Concentrations of acetochlor above the field rate did not affect the bioremediation process in the water system whereas it did in soil pots. Furthermore, bioremediation in water system was nearly completed in 15 days whereas it did not reach high percentage?in the soil system. These encouraging results are new contribution in field of bioremediation of pesticide by cyanobacterial mats and suggest that application of cyanobacterial mat could be a fast and suitable methodology for bioremediation of organic pollutant in the ecosystem.
文摘Effects of four kinds of triazine herbicides on the photodegradation of acetochlor were studied on glass surface and in aqueous solution under three kinds of light sources, i.e., xenon lamp, high pressure mercury lamp and natural sunlight. The results indicated that atrazine, simetryne, prometryne and ametryne exhibited significant effects on the photoquenching degradation of acetochlor, and there was an obvious positive correlation between their effects and the dosage of four kinds of triazine herbicides.
文摘Adsorption of phenthoate and acetochlor onto kaolin, montmorillonite, bentonite clays and respective organoclays prepared by the exchange of quaternary ammonium as tetradecyltrimethyl ammonium bromide(TTAB), dodecyltrimethylammonium bromide(DTAB), and cetylpyridinium chloride(CPC) were studied. The adsorption equilibrium data points were fitted to Freundlich isotherm equations. The adsorption of phenthoate and acetochlor were significantly enhanced by surfactant treatment of the clays. The amount of both pesticides adsorbed per unit mass of organoclay followed the order of TTA-kaolin < TTA-montmorillonite < TTA-bentonite, which is inconsistent with the organic carbon content of the clays. The removal efficiency of organomontmorillonite to treat acetochlor is in the order of CP(C 16 )-montmorillonite > TTA(C 14 )-montmorillonite > DTA(C 12 )-montmorillonite. Phenthoate is adsorbed to greater extent than acetochlor by each adsorbent, which may be due to the higher hydrophobicity of phenthoate, indicating considerable hydrophobic interaction between adsorbent/adsorbate systems.
基金Supported by the Hunan Provincial Science and Technology Innovation Plan Program (NO. 2019NK4170)the Important Project of Hunan Province Education Department (NO. 19A259)。
文摘[Objectives] This study was conducted to investigate the toxic effect of acetochlor in loaches. [Methods]Loaches were put into the acetochlor solution with concentrations of 0,0. 062 5,0. 125,0. 25,0. 5 and 1 μl/L,respectively. The effects on dismutase( SOD),peroxidase( POD),catalase( CAT) and glutathione( GSH) activity and malondialdehyde( MDA) content in the liver of loaches were analyzed after 12,24,48 and 72 h of exposure. [Results] The activity of SOD,POD,CAT and GSH increased with the stress time and concentration,reached their maximums at 48 h after acetochlor treatment,and then decreased.However,MDA content increased with the stress time and concentration. [Conclusions] Acetochlor had obvious oxidative stress on loaches,and the activity of SOD,POD,CAT and GSH showed an obvious induction-inhibition effect with the increase of acetochlor concentration and the extension of stress time.
