Please use this identifier to cite or link to this item: https://hdl.handle.net/11681/47067
Title: A laboratory study of the turbidity generation potential of sediments to be dredged
Authors: Wechsler, Barry A.
Cogley, David R.
Keywords: Sediments
Dredging spoil
Dredged material
Suspended sediments
Turbidity
Publisher: U.S. Army Engineer Waterways Experiment Station
Series/Report no.: Technical Report (Dredged Material Research Program (U.S.)) ; no. D-77-14
Abstract: In order to understand the effects of physical and chemical factors which control particle settling rates and thereby develop the means to predict the extent of dredging—related turbidity, a series of laboratory jar tests was performed. The turbidity of suspensions of three pure clay samples and eight natural sediments was monitored as a function of time in waters of various salinity, hardness, and pH. The results were statistically analyzed to relate specific sediment and water compositional factors to observed settling rates and to evaluate their relative importance. Additional experiments were per-formed to characterize the nature of turbidity. While turbidity was found to be extremely persistent in soft fresh waters, hardness (200 mg/ℓ) and particularly salinity (1-5 ppt) induced flocculation and consequently rapid settling. The organics content was the principal sediment component affecting turbidity, with higher organics levels correlated with more rapid settling in salt water. No significant segregation of sediment components was observed during settling, with the exception of coarser silt particles, which settled independently of clay-organic aggregates. A turbidity plume model was developed which accounts for flocculation in suspensions of dredged material. Appendixes A-F were reproduced on microfiche and are enclosed in an envelope attached inside the back cover. Appendixes G and H follow the main text.
Description: Technical Report
Gov't Doc #: Technical Report D-77-14
Rights: Approved for Public Release; Distribution is Unlimited
URI: https://hdl.handle.net/11681/47067
Size: 191 pages / 11.58 MB
Types of Materials: PDF/A
Appears in Collections:Technical Report

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