Geotubes have proven to be a practical and economical way of dewatering a number of domestic and industrial sludges, and sediments, such as river and lake sediments and contaminates, wastewater lagoon sludge, water treatment plant sludge, packinghouse sludges and wood products sludges. The Michigan Department of Environmental Quality (MDEQ) is interested in evaluating Geotubes as a method of dewatering material from the lagoons and the ditches at the CPC site located in Monroe, Michigan, as an alternative to the conventional mechanical methods of dewatering material.
Dewatering & Containment Technologies, Inc. (DCT) along with Infrastructure Alternatives, Inc., (IAI) in Michigan, established the objectives of a pilot test, developed a sampling and analytical program and the general work program for the test. These items were completed with input from the MDEQ and Weston Consulting. IAI performed the test and DCT functioned as the primary author of this summary report.
Pilot Test Objectives
The following objectives for the pilot test were developed by the parties and were incorporated into the project.
Objective 1: Evaluate solids capture. Solids retention or losses was determined by collecting filtrate samples from the hanging bag tube. Samples were collected from below the tube. It was possible to isolate the filtrate and collect discrete samples on a timed basis.
Objective 2: Determine the chemical composition of filtrate. Samples of the filtrate were analyzed for parameters to determine impact on removal of solids and fate of PCB's known to be present in the West ditch material from the Monroe site.
Objective 3: Evaluate solids dewatering factors. Cake samples of the thickened, dewatered solids were taken at day 10 of the test and compared to the solids concentration of the feed sludge to determine shrinkage factors. Dewatering rate was recorded as well Filtrate was collected and the volume was measured over time to determine how rapidly the material casts off water. This information is then used to determine capacity values in full-scale applications.