Dissertation > Excellent graduate degree dissertation topics show

Impacts of Chlorothalonil on Degradation Behavior of Chlorpyrifos, Butachlor

Author: FengBo
Tutor: YuYunLong
School: Zhejiang University
Course: Pesticides
Keywords: chlorothalonil chlorpyrifos butachlor combined pollution degradation soil environmental behaviour
CLC: X592
Type: Master's thesis
Year: 2006
Downloads: 186
Quote: 1
Read: Download Dissertation

Abstract


Pesticides are purposefully introduced into agricultural systems for the protection of crops against harmful organism. A series of side effects on environmental quality, safety of agricultural products, and human health caused by pesticide residues has been reported. There is an increasing concerns on risk assessment of pesticide residues, and a great deal of studies have been conducted to examine the fate of pesticides in the environment. However, little information is available to describe fate of multiple pesticides co-existed in the environment.In this study, chlorpyrifos, chlorothalonil and butachlor were choosed as models of insecticide, fungicide and herbicide to examine their degradation behaviors alone and in combination.The data obtained in this study indicated that the degradation curves of chlorpyrifos, chlorothalonil and butachlor in soil were fitted to the first-order equation. The degradation rate constants of chlorpyrifos, chlorothalonil and butachlor at low concentration were 0.0330, 0.2092 and 0.1013, respectively. The corresponding half-lives for chlorpyrifos, chlorothalonil and butachlor were calculated to be 21.0d, 3.3d and 6.8d, respectively. The half-lives of chlorpyrifos, chlorothalonil and butachlor at higher concentration were 26.2d, 3.5d, 7.2d, respectively. The degradation rate of chlorpyrifos at low concentration was significantly (P<0.05) faster than that at higher concentration in soil, whereas no significant difference for chlorothalonil and butachlor degradation was observed between low and higher concentrations.The degradation rate constants of chlorpyrifos combined chlorothalonil at low and high levels were measured to be 0.0264, 0.0246 with half-lives of 26.3d, 28.2d, respectively. Compared to those for chlorpyrifos alone existed in soil, the degradation of chlorpyrifos was slightly inhibited by the addition of chlorothalonil at high concentration. A similar effect of chlorothalonil on butachlor degradation was observed. The degradation rate constants of butachlor combined with chlorothalonil atlow and high levels were determined to be 0.0846, 0.0563, and their half-lives were 8.2d, 12.3d. The date indicated that degradation of butachlor in soil was indistinctively inhibited by the existing of chlorothalonil at low concentration, and was significantly inhibited by the existing of chlorothalonil at high concentration. It has been reported that soil microorganisms are inhibited by the addition of chlorothalonil. It is likely that the inhibitory effect of chlorothalonil on soil microorganisms caused the decreased degradation of chlorpyrifos and butachlor.The results suggested that the degradation behaviours of multiple pesticides co-existing in soil differ from those of single in soil. The difference depends on the amount and species of the pesticide existing together.

Related Dissertations

  1. Study on the Degradation of Unsaturated Polyester Resin and Fiber Reinforced Polymer in Hot Compressed Water,TQ320.1
  2. Study on the Improvement Depth of Dynamic Consolidation by Methods of Mathematical Physics,TU472.31
  3. Effect of Soil Erosion on Soil Quality in the Cultivated Slope Land on the Loess Plateau, China,S157.1
  4. Cloning, Expression and Functional Analysis of STOP1 Transcriptional Factor,S336
  5. Process Optimization and Degradation Kinetics for Microwave Vacuum Drying of Different Traditional Chinese Medicine Extract,TQ461
  6. Effects of the Exotic Invasive Plant Solidago Canadensis L. on the Community Structure of Soil Anmals,S451
  7. Study on the Preparation of the Low Molecular Weight Fuciodan from Sargassum Henslowianum (C.Agardh) and Anti-tumor Activity,TS254.9
  8. Study on Activated Carbon Supported Cerium Catalytic Ozone Oxidation of Chloramphenicol,X703
  9. The Study of Preparation and Photocatalytic Activity of TiO2 by Electrospinning,O614.411
  10. Process and Mechanism of Eucalyptus Pulp Bleaching Catalysed by Cu2+/Co2+,TS745
  11. Lijiang River,RS and GIS - based Soil Erosion Research,S157
  12. The Research on Sulfate Leaching Properties of Cation-exchange Resin Used in Power Plants,TQ425.23
  13. Activation of Polycyclic Aromatic Hydrocarbons in Soils by Root Exudate and Its Components,X53
  14. Study on Nitrogen Removal by Soil Aquifer Treatment Process That Enhanced Nature Reoxygenation and Effective Volume,X703
  15. Risk Analysis and Mitigation Experiment of Heavy Metal Pollution in Croplands in Vicinity of Pollution Sources,X820.4
  16. Study of Nitrobenzene Wastewater’s Treatment by Combination of Immobile Phanerochaete Chrysosporium and Activated Sludge,X703
  17. Subarea Management of Tobacco Soil Nutrients and Adequate Fertilization Research by Micro Scale,S158
  18. Soil Organic Carbon Fractions and Its Dynamic in Different Soil Types of Wuyi Mountains,S153.6
  19. Research on Rainfall Erosivity in Jiangsu Province,S157.1
  20. Effect of Black Carbon Addition on Soil Organic Carbon Decomposition,S153.6
  21. A Research on Determinating Soil Types and Soil Boundaries under Chinese Soil Taxonomy,S155

CLC: > Environmental science, safety science > Environmental pollution and its prevention > Agricultural chemicals,toxic chemicals, pollution and its prevention
© 2012 www.DissertationTopic.Net  Mobile