Environmental Remediation of a Shallow Mesotrophic Lake Water Using On-Site Non-woven Geotextile Filtration Treatment

Abstract

For remediation of eutrophic waters, which are often shallow and inland, such as lakes, several processes are applied. Present techniques include one or a combination of the following: contaminated sediment removal by dredging, chemical substances or inert element addition in the water column, and water aeration. These processes are often inadequate, invasive, and intricate, changing the natural biota. To respond to this concern and present an environmental, easily applicable, deployable, and operational method on-site non-woven geotextile filtration treatment has been proposed. The experiment was deployed throughout the summer until mid-fall of 2020, using the water from Lake Johanne, a shallow mesotrophic lake located in the Sainte-Anne-des-Lacs municipality in Quebec. Based on a tank located near the lakeshore with a floating geotextile filtration system in batch and continuous mode (i.e., of 2-, 1-, and 0.5-day retention time), lake water was filtered using non-woven geotextiles. The water parameters monitored during the experiment were total phosphorus (TP), nitrate, chemical oxygen demand (COD), total suspended solids (TSS), particle size, and turbidity. The non-woven geotextile filters were effective for removing nutrients, organic matter, and suspended particles in the contained water and resulted in about 86% TSS removal and an average of 75% and 11% for TP and COD removal, respectively. All treated water was returned into the lake. The feasibility of treatment has been proven for the possible remediation of this shallow mesotrophic lake.