Monday, November 13, 2006

A Research Facility that Enables Replicated Experimentation on both Water and Air Quality Effects of Pilot-Scale Treatment Wetlands.

Andrew Vanderzaag1, Vimy Glass2, Robert Gordon2, David Burton3, Ali Madani2, Glenn Stratton2, and Claudia Wagner-Riddle4. (1) Dalhousie Univ., Halifax, NS B2N 2P6, Canada, (2) Nova Scotia Agricultural College, 7 Hampstead Ct. Apt. 4, Truro, NS B2N 3E5, Canada, (3) Nova Scotia Agric. College, "Po Box 550, Dept. Of Env. Sci", Truro, NS B2N 5E3, CANADA, (4) Univ of Guelph, Dept. of Land Resource Science, Guelph, ON N1G 2W1, Canada

From a functional standpoint, treatment wetlands are a useful method for treating wastewater. From a research standpoint, however, treatment wetlands can be challenging because of the inherent variability present in natural systems. Our objective was to develop a research facility that enables replicated experimentation and simultaneous analysis of wastewater treatment and air quality effects. To achieve replication, the facility has six identical concrete cells (6.6 m2). Each cell can be configured to suit various treatment objectives, such as substrate type, vegetation, or water depth. Wastewater input to each cell is controlled by peristaltic pumps, and outflow from each cell is measured by calibrated tipping buckets. This allows contaminant loading and mass removals to be calculated, based on laboratory analysis of the treated and untreated wastewater. To achieve continuous analysis of air quality effects, each cell is covered by a flow-through chamber. This micrometeorological approach enables continuous flux measurements of multiple gases, while avoiding cross-over effects among different treatments. The research facility is described in detail. Advantages and possible limitations of the system during the initial 3 years of research are discussed.