Assessing the effectiveness and environmental impacts of using natural flocculants to manage turbidity.

Details

• Creators:
  Li, Qilin ; Kegley, Laura
• Corporate Contributors:
  Oregon. Dept. of Transportation. Research Unit ; United States. Federal Highway Administration
• Subject/TRT Terms:
  Best Management Chitosan Flocculating Agents In-stream Construction Practices Turbidity Underwater Construction
• Publication/ Report Number:
  FHWA-OR-RD-06-06
• Resource Type:
  Tech Report
• Geographical Coverage:
  Oregon
• Corporate Publisher:
  Oregon. Dept. of Transportation. Research Unit
• Abstract:
  The objective of this research was to determine the feasibility of using chitosan as a natural flocculant to control
  
  turbidity during in-stream construction work. A series of field tests in Oak Creek, Corvallis, OR were conducted in
  
  order to test the effectiveness for turbidity control and the environmental impacts of applying chitosan directly into a
  
  stream environment. No significant removal was obtained with chitosan doses up to 0.5 mg/L under the conditions
  
  tested, mostly due to high pH of the creek and other unfavorable water quality parameters. Water quality analysis for
  
  total organic carbon, total phosphorus, total Kjeldahl nitrogen, and biochemical oxygen demand showed that chitosan
  
  does not adversely impact the aquatic environment at low doses.
  
  Due to the inconclusiveness of the field test data, a series of bench-scale tests were conducted to evaluate the
  
  effectiveness of chitosan under controlled conditions, as well as its responses to different test conditions, e.g. pH, initial
  
  turbidity, chitosan dose and sediment type. The bench scale tests were conducted using water collected from Oak
  
  Creek and a standard jar tester. It was found that flocculation efficiency depends strongly on sediment type. However,
  
  the most critical factor that determines the effectiveness of chitosan seems to be an unidentified water quality
  
  parameter, which is likely related to the organic matter in the stream.
  
  
• Format:
  PDF
• Funding:
  SPR 615
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:b8b5ca9b577251efe9a6aaf622c67a41fe3a58f25652c2f5912d443c91d584cd
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/22579/dot_22579_DS1.pdf
• File Type:
  [PDF - 1.20 MB ]