Field Study of an Innovative Sediment Capture Device: Bottom Grid Structure

• Published in: Water, air, and soil pollution Vol. 225; no. 6; pp. 1 - 11
• Main Authors: He, Cheng, Post, Yvonne, Rochfort, Quintin, Marsalek, Jiri
• Format: Journal Article
• Language: English
• Published: Cham Springer-Verlag 01.06.2014; Springer International Publishing; Springer; Springer Nature B.V
• Subjects: Aids; Analysis; Atmospheric Protection/Air Quality Control/Air Pollution; Bottom sediments; Climate Change/Climate Change Impacts; Design; Devices; Earth and Environmental Science; Environment; Environmental monitoring; Experiments; Field study; filtration; Flow rates; High flow; Hydraulics; Hydrogeology; Laboratories; Particle size; Performance evaluation; Phosphorus; Pollutants; Ponds; Runoff; Sedimentation; Sedimentation & deposition; Sediments; Sediments (Geology); Settling; Soil Science & Conservation; Stormwater; Stormwater management; Studies; Velocity; Vortices; Water Quality/Water Pollution; Water treatment; Enhancing sedimentation; Particle removal rate; 3D hydraulic modeling; Retention pond
• ISSN: 0049-6979; 1573-2932
• DOI: 10.1007/s11270-014-1976-z

An innovative device for enhancing particle settling, referred to as the bottom grid structure (BGS), was tested in the forebay of an urban stormwater detention pond in two design variants. Results showed that compared to the simulated bare pond bottom (i.e., a reference condition), the BGSs collected more sediments during a three-month test period and also captured and retained some very fine particles (<32 μm) even under high flows. The improvements of particle removal rates expressed in multiples of removals for the bare bottom were 3.6, 7.3, and 11.2, respectively, for the particle size ranges 106 μm < D < 250 μm, 32 μm < D < 106 μm, and D < 32 μm. Because the BGS can retain much smaller particles than bare bottom sediment traps, the application of the BGS can be considered as equivalent to increasing the settling area of a particle removal facility about 5 to 60 times, depending on the size of settleable particles under consideration. This characteristic distinguishes the BGS from other sedimentation enhancement methods and makes it possible to treat stormwater with a wide particle size spectrum under high flow rates, with a relatively small footprint, and without using chemical settling aids or filtration.