Practical Aspects of a Reactive Geocomposite to Remediate Contaminated, Subaqueous Sediments

摘要

The paper describes the development of a reactive geocomposite for the remediation of subaqueous, contaminated sediments. This concept is an alternative to the current practices of either dredging these sediments and treating them ex situ, or capping the sediments with natural and/or synthetic materials. Both of these existing methods have significant drawbacks that preclude their use in many situations. The paper summarizes the results of two series of benchtop tests performed to assess the feasibility of this concept. First, one-dimensional consolidation tests were performed on a kaolinite sediment with an overlaid, filtering geotextile (either woven or non-woven) layer. The second series consisted of sorption isotherm testing of lead ions in solutions of various pH and salt concentration, for both kaolinite and zeolite. The zeolite was selected as the potential reactive material to be placed in the geocomposite. These benchtop tests show the effects of geotextile layering on the consolidation behavior, and show the effectiveness of zeolite in binding the lead ions under a variety of pore fluid chemistry conditions. A concept for the field implementation of the reactive geocomposite is presented, including methods for fabricating the material and placing it in the field.