Metal cation binding to Sphagnum peat and sawdust: Relation to wetland treatment of metal-polluted waters.
Interest in the potential use of constructed and naturally-occurring wetland systems as a low-cost, low-maintenance method for the treatment of metal-polluted water has increased considerably in recent years. Because metal cation binding to organic matter represents one mechanism by which metals are retained in wetlands, laboratory studies were conducted of the binding of metal cations to Sphagnum peat and sawdust, two substrates used in wetland construction for treatment of metal-polluted waters. The two substrates differed in initial cation exchange characteristics, organic matter fractionation, affinities for ten different metal cations, and metal binding capacities. Results suggest a simple method for quantitatively assessing the potential for different types of organic substrates to retain metals by binding when exposed to metal-polluted water of a particular chemical composition. For metals that are retained in wetlands principally by binding to organic matter, application of the method could lead to an improved ability to formulate a priori cost-benefit analyses for contemplated wetland treatment of metal-polluted waters.
|Main Author:||Wieder, R Kelman.|