Dissertation > Excellent graduate degree dissertation topics show

Dianshan Lake Ecological Risk Assessment Model and Its Application

Author: LiuYang
Tutor: LinWeiQing
School: Donghua University
Course: Environmental Science
Keywords: Dianshan lake AQUATOX model exposure assessment ecological risk assessments(EPA) dichloromethane
CLC: X826
Type: Master's thesis
Year: 2012
Downloads: 109
Quote: 1
Read: Download Dissertation

Abstract


With rapid development of the industry and agriculture in recent years, many new chemicals have been created, more and more organic pollutants have been discharged into water through various ways including the emissions of solid, liquid, and gas wastes, precipitation, and runoff. These pollutants, especially with a large amount released via accidental spills within a short period of time, can severely degrade water environment, aquatic ecological integrity and human health. Consequently organic pollution in water has become a major environmental concern. But the current water environment research still mainly focuse on the eutrophication.This study uses USEPA’s ecological risk assessment as a framework to develop an approach to assess environmental risk of organic compound in water environment. An ecological toxicity model—AQUATOX was used to simulate dichloromethane concentrations and evaluate its ecological risk in Dianshan Lake. The following are the major results:Organic pollutants, mainly dichloromethane were detected in Dianshan Lake. Routine environmental monitoring showed that the highest concentration of dichloromethane was 0.041mg/l in Qiandengpu in March 2011.AQUATOX toxicological and ecological simulation model of dichloromethane in Dianshan Lake was developed. The model was used to simulate the exposure of the dichloromethane in the water. Using the Hazardous Quotient method, the estimated risk for dichloromethane was 0.3978, indicating that the risk of Dianshan Lake dichloromethane is relatively low but long-term monitoring of the dynamic lake environment and organic pollutants is still required. A sensitivity analysis of the main factors that influence the concentration of dichloromethane in water was performed. Aerobic microbial activity had more effects on the concentration of dichloromethane in water than other physical and chemical factors. Biocumulation of dichloromethane in algae and zooplankton species was also examined and biocumulation in the biota was very low.Finally, a series analysis simulating sudden pollution accidents of dichloromethane in Dianshan lake was performed. The result showed that when the input quality of dichloromethane in Dianshan lake up to 5 ton, the highest concentration of dichloromethane in water will exceed the drinking water standard. When the quality of dichloromethane increases to 100 ton, the time that concentration of dichloromethane decreases to the drinking water standard through the water self-purification will be 45 days, longer than Dianshan Lake’s the longest hydraulic retention time in a year. The slow degradation speed may pose environmental risk for Dianshan lake as Shanghai drinking water source. The degradation time of organic in water is decreased significantly, with the rise of temperature. Therefore, pollution accidents occurred in winter will pose higher risk than ones in summer.

Related Dissertations

  1. Removal Characteristics and Mechnism of Dichloromethane Photodegradation by Irradiation of Vacuum Ultraviolet,X511
  2. Absorption - Photo-assisted oxidation process emissions of methylene chloride,X701.7
  3. Shanghai Dianshanhu regional agricultural nonpoint source pollution and its effect on water quality impact study Dianshanhu,X524
  4. Toxic Effects of Dichloromethane and Dichloroethane to Chlorella Pyrenoidesa,X173
  5. Isolation of Dichloromethane-Degrading Strain and the Reserach on Preparation of Composite Microoranism Agent and Constructing the Genomic Bank,X172
  6. Primary Study on Exposure Assessment and Risk Management of Formaldehyde in Aquatic Products,TS254.7
  7. Dianshanhu temporal Characteristics of Microcystis populations and alert significance,X173
  8. Mn-based catalyst catalytic oxidation of VOCs,O643.36
  9. Study of Catalytic Combustion of VOCs over Chromium-based Catalysts,O643.36
  10. The Analysis of Dichloromethane, Chloroform and Toluene in Liang Jiang, Min Jiang River with GC-MS,X832
  11. Processing of Dichloromethane Gas by Catalytic Reduction with Bimetallic Iron Particles,X701.7
  12. Cedar pine needles dichloromethane extract the chemical constituents of the extraction process and discuss shikimate,R284.1
  13. Studies of Thermodynamic Properties of Binary Mixtures of Chloralkane and Aromatic Compounds,O621.24
  14. Preparing Budsonide Ultrafine Powder by Supercritical Anti-Solvent (SAS) Method,TB383.3
  15. The fungicides and raw materials synthesis,O621.25
  16. The Study on Adsorption of Dichloromethane at Activated Carbon and Simulation of Its Breakthrough Curve,X132
  17. Rare earth catalysts adipic acid anhydride ring-opening polymerization,O631.5
  18. An Exerperimental Investigation on the Photodissocition Dynamics of Ch3Br and CH2Cl2 with UV Laser,O643.1
  19. Purifying and Recovery Volatile Organic Compounds by Abosorrption and PSA Methods,X701
  20. Preparation, Structure and Properties of SF/PVA Blending Nanofibers with a Ternary Solvent,TB383.1
  21. Glucosamine saponins glycosylation,R914

CLC: > Environmental science, safety science > Environmental Quality Assessment and Environmental Monitoring > Analysis and Evaluation of Environmental Quality > Biological assessment, ecological assessment
© 2012 www.DissertationTopic.Net  Mobile