This study investigated the adsorption potential of diuron and linuron in selected soil samples collected from agricultural area of Gaza Strip, Palestine and correlated the adsorption results to the soil properties. T...This study investigated the adsorption potential of diuron and linuron in selected soil samples collected from agricultural area of Gaza Strip, Palestine and correlated the adsorption results to the soil properties. The adsorption experiments are based on the batch equilibrium technique and UV-Spectrophotometer method to determine the equilibrium concentration of both herbicides. Results of adsorption experiment showed that linuron and diuron are adsorbed in various amounts in Gaza soils according to the variation in pH, organic matter and clay content. Adsorption isotherms of both herbicides were linear in the tested concentration. Fitting the adsorption data to Freundlich equation showed good fitting and Freundlich constants were less than one indicating physical adsorption processes. It is concluded that soil organic matter and pH affect the adsorption of both herbicides. These results provided a better understanding of the behavior of diuron and linuron in Gaza soils.展开更多
Diuron is a herbicide widely used in the Middle East;its field application creates many environmental problems. This study investigated the bioremediation of Diuron in soil environment by Cyanobacterial mats collected...Diuron is a herbicide widely used in the Middle East;its field application creates many environmental problems. This study investigated the bioremediation of Diuron in soil environment by Cyanobacterial mats collected from Gaza Wadi. Various concentrations of Diuron were injected in water saturated soil samples pre-treated with Cyanobacterial mat for several periods. Percent growth of Jews mallow as a test plant was taken as indicator of biodegradation of Diuron. Results showed that Diuron was degraded in soil and degradation was more pronounced when Diuron was incubated with Cyanobacterial in the irrigation water. Larger applied rate of Cyanobacterial mat did not affect the biodegradation of Diuron. These encouraging results suggest that application of Cyanobacterial mat could be a suitable method to remediate soil pollution.展开更多
This study investigated the leaching potential of diuron and linuron in different soil types in Gaza Strip, Palestine under laboratory and field conditions. Leaching potential was evaluated by tin columns and bioassay...This study investigated the leaching potential of diuron and linuron in different soil types in Gaza Strip, Palestine under laboratory and field conditions. Leaching potential was evaluated by tin columns and bioassay technique using Molokhia as test plant. The responses of the test plant were regressed versus concentrations of the herbicide to estimate linear regression equation and the regression coefficient. The obtained results indicate strong positive association between Molokhia and concentrations of diuron or linuron;accordingly it was used in the bioassay and estimation of the concentrations of the tested herbicides in the leaching depth. Leaching potential was very low in North Gaza and Kkan Younis soil, whereas in the Meddle zone soil was very large. Leaching potential under laboratory conditions was larger that under field conditions. The bioestimated concentrations in soil layer under field conditions were sever folds of magnitude lower than those under laboratory conditions. The interesting outcome of this study is that leaching potential is dependent on soil clay fraction, soil organic matter, and soil pH. These results provided answers to the questions raised by farmers in Gaza Strip.展开更多
The chorophyll fluorescence ratio F685/F735 in vivo can be a useful indicator for stress detection inhigher plants and seaweed. DCMU [3 - (3, 4 - dichlorophenyl ) - 1, 1 - dimethylurea] treatment influencesthis ratio....The chorophyll fluorescence ratio F685/F735 in vivo can be a useful indicator for stress detection inhigher plants and seaweed. DCMU [3 - (3, 4 - dichlorophenyl ) - 1, 1 - dimethylurea] treatment influencesthis ratio. Th effects of DCMU on F685/F735 of marine red, brown and green algae under excitationlight of different wavelengths were investigted. In the brown algae, Laminaria japonica and Undariapinnatifida,DCMU did not increase this ratio under blue light excitation but increased the ratio slightlyunder excitation by green light. For the red algea, Halymenia sinensis, DCMU increased the ratiomarkedly under both blue and green ligh excitation. The percentage increase could reach 50% (undergreen light excitation) and was due to unequal enhancement at the two emission maxima by DCMU. Afraction of chlorophyll which contributed to fluorescence in the 735 nm region was less sensitive toDCMU and was likely from photosystem I of red algae. In the green alga, Ulva pertusa, DCMU causeda slight increase in展开更多
The digestion regularity of MCPA, ametryn and dim＇on which were the active ingredients of 55% MCPA · ametryn · diuron WP in sugarcane leaves and soil of sugarcane plantation collected from Changsha of Hunan...The digestion regularity of MCPA, ametryn and dim＇on which were the active ingredients of 55% MCPA · ametryn · diuron WP in sugarcane leaves and soil of sugarcane plantation collected from Changsha of Hunan Province and Haikou of Hainan Province in 2009 and 2010were studied in the paper, and the results showed that these three agents had rapid digestion. The final residue test showed that beth MCPA and ametryn had not been detected in the study; the average resi- dues of diuron in the soil collected from Hunan Province in 2009 and 2010 were 0.018 and 0.015 mg/kg, respectively which were slightly larger than the critical value of 0. 013mg,/kg; diuron had no been detected in other treatments.展开更多
The pollution level of diuron in seawater and sediments in the west coastal sea area of Zhoushan Island from 2011 to 2013 was investigated. Results revealed that the concentration of diuron in seawater varies from les...The pollution level of diuron in seawater and sediments in the west coastal sea area of Zhoushan Island from 2011 to 2013 was investigated. Results revealed that the concentration of diuron in seawater varies from less than (3.0 to 52.1) ng·L-1, with an average level of less than 11.1 ng.L-1. The annual average content was less than 7.9 ng.L-1, 13.9 ng.L-1, and 12.3 ng.L-1 in 2011, 2012, and 2013, respectively. The concentrations of diuron in marine sediments also varied from less than (0.3 to 3.9) ng.g-1 (dry weight), with an average concentration of less than 1.13 ng g-1 (dry weight). The annual average concentration was less than 0.851 ng.g-1, 1.328 ng.g-1, and 1.202 ng.g-1 in 2011, 2012, and 2013, respectively. The accumulation of diuron in seawater and sediments may pose a potential risk to the marine ecosystem of the investigated sea area.展开更多
Ultraviolet mutagenesis was applied to Nannochloropsis oculata and three mutants resistant to 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) were isolated. The cellular chlorophyll a and total lipid content of the wil...Ultraviolet mutagenesis was applied to Nannochloropsis oculata and three mutants resistant to 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) were isolated. The cellular chlorophyll a and total lipid content of the wild are higher in the medium supplemented with DCMU than in the control without DCMU. Without DCMU, the growth rates and chlorophyll a contents of the mutants are similar to those of the wild. Significant changes of fatty acid content and composition have occurred in DCMU-resistant mutants growing in the medium supplemented with DCMU. The total lipid, palmitic acid (16∶0), palmitoleic acid (16∶1ω9) and oleic (18∶1ω9) contents decrease significantly, while the vaccenic acid (18∶1ω11) increases significantly and the EPA content of dried powder increases slightly in the mutants. The study may provide a basis to improve EPA content in Nannochloropsis oculata in the future.展开更多
文摘This study investigated the adsorption potential of diuron and linuron in selected soil samples collected from agricultural area of Gaza Strip, Palestine and correlated the adsorption results to the soil properties. The adsorption experiments are based on the batch equilibrium technique and UV-Spectrophotometer method to determine the equilibrium concentration of both herbicides. Results of adsorption experiment showed that linuron and diuron are adsorbed in various amounts in Gaza soils according to the variation in pH, organic matter and clay content. Adsorption isotherms of both herbicides were linear in the tested concentration. Fitting the adsorption data to Freundlich equation showed good fitting and Freundlich constants were less than one indicating physical adsorption processes. It is concluded that soil organic matter and pH affect the adsorption of both herbicides. These results provided a better understanding of the behavior of diuron and linuron in Gaza soils.
文摘Diuron is a herbicide widely used in the Middle East;its field application creates many environmental problems. This study investigated the bioremediation of Diuron in soil environment by Cyanobacterial mats collected from Gaza Wadi. Various concentrations of Diuron were injected in water saturated soil samples pre-treated with Cyanobacterial mat for several periods. Percent growth of Jews mallow as a test plant was taken as indicator of biodegradation of Diuron. Results showed that Diuron was degraded in soil and degradation was more pronounced when Diuron was incubated with Cyanobacterial in the irrigation water. Larger applied rate of Cyanobacterial mat did not affect the biodegradation of Diuron. These encouraging results suggest that application of Cyanobacterial mat could be a suitable method to remediate soil pollution.
文摘This study investigated the leaching potential of diuron and linuron in different soil types in Gaza Strip, Palestine under laboratory and field conditions. Leaching potential was evaluated by tin columns and bioassay technique using Molokhia as test plant. The responses of the test plant were regressed versus concentrations of the herbicide to estimate linear regression equation and the regression coefficient. The obtained results indicate strong positive association between Molokhia and concentrations of diuron or linuron;accordingly it was used in the bioassay and estimation of the concentrations of the tested herbicides in the leaching depth. Leaching potential was very low in North Gaza and Kkan Younis soil, whereas in the Meddle zone soil was very large. Leaching potential under laboratory conditions was larger that under field conditions. The bioestimated concentrations in soil layer under field conditions were sever folds of magnitude lower than those under laboratory conditions. The interesting outcome of this study is that leaching potential is dependent on soil clay fraction, soil organic matter, and soil pH. These results provided answers to the questions raised by farmers in Gaza Strip.
基金This research was supported by the Foundation of the Chinese National Education Committee and EMBL,Chinese Academy of Sciences.
文摘The chorophyll fluorescence ratio F685/F735 in vivo can be a useful indicator for stress detection inhigher plants and seaweed. DCMU [3 - (3, 4 - dichlorophenyl ) - 1, 1 - dimethylurea] treatment influencesthis ratio. Th effects of DCMU on F685/F735 of marine red, brown and green algae under excitationlight of different wavelengths were investigted. In the brown algae, Laminaria japonica and Undariapinnatifida,DCMU did not increase this ratio under blue light excitation but increased the ratio slightlyunder excitation by green light. For the red algea, Halymenia sinensis, DCMU increased the ratiomarkedly under both blue and green ligh excitation. The percentage increase could reach 50% (undergreen light excitation) and was due to unequal enhancement at the two emission maxima by DCMU. Afraction of chlorophyll which contributed to fluorescence in the 735 nm region was less sensitive toDCMU and was likely from photosystem I of red algae. In the green alga, Ulva pertusa, DCMU causeda slight increase in
基金Supported by Scientific and Technological Projects of Nanning Municipal Science and Technology Bureau(20132308)
文摘The digestion regularity of MCPA, ametryn and dim＇on which were the active ingredients of 55% MCPA · ametryn · diuron WP in sugarcane leaves and soil of sugarcane plantation collected from Changsha of Hunan Province and Haikou of Hainan Province in 2009 and 2010were studied in the paper, and the results showed that these three agents had rapid digestion. The final residue test showed that beth MCPA and ametryn had not been detected in the study; the average resi- dues of diuron in the soil collected from Hunan Province in 2009 and 2010 were 0.018 and 0.015 mg/kg, respectively which were slightly larger than the critical value of 0. 013mg,/kg; diuron had no been detected in other treatments.
文摘The pollution level of diuron in seawater and sediments in the west coastal sea area of Zhoushan Island from 2011 to 2013 was investigated. Results revealed that the concentration of diuron in seawater varies from less than (3.0 to 52.1) ng·L-1, with an average level of less than 11.1 ng.L-1. The annual average content was less than 7.9 ng.L-1, 13.9 ng.L-1, and 12.3 ng.L-1 in 2011, 2012, and 2013, respectively. The concentrations of diuron in marine sediments also varied from less than (0.3 to 3.9) ng.g-1 (dry weight), with an average concentration of less than 1.13 ng g-1 (dry weight). The annual average concentration was less than 0.851 ng.g-1, 1.328 ng.g-1, and 1.202 ng.g-1 in 2011, 2012, and 2013, respectively. The accumulation of diuron in seawater and sediments may pose a potential risk to the marine ecosystem of the investigated sea area.
基金support of the National Advanced Technology‘863’Project Foundation(819-02-01).
文摘Ultraviolet mutagenesis was applied to Nannochloropsis oculata and three mutants resistant to 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) were isolated. The cellular chlorophyll a and total lipid content of the wild are higher in the medium supplemented with DCMU than in the control without DCMU. Without DCMU, the growth rates and chlorophyll a contents of the mutants are similar to those of the wild. Significant changes of fatty acid content and composition have occurred in DCMU-resistant mutants growing in the medium supplemented with DCMU. The total lipid, palmitic acid (16∶0), palmitoleic acid (16∶1ω9) and oleic (18∶1ω9) contents decrease significantly, while the vaccenic acid (18∶1ω11) increases significantly and the EPA content of dried powder increases slightly in the mutants. The study may provide a basis to improve EPA content in Nannochloropsis oculata in the future.
