AN EXPERIMENTAL STUDY OF THE EFFECTIVENESS OF FOUR WETLAND PLANT SPECIES AND COMMUNITY COMPOSITION FOR WASTEWATER TREATMENT

The purpose of our study was to answer two questions: (1) are certain plants more efficient at treating wastewater and (2) do combinations of plants enhance treatment? We used microcosms, five gallon buckets filled with a peaty soil, and housed at the Bath Nature Preserve in Bath, Ohio. The study began in August 2001 and ran until October 2001. The experiment was a 6 x 2 factorial design: six plant treatments [no plants, Carex lacustris, Scirpus validus, Phalaris arundinacea, Typha latifolia and the combination of all four plants] and two treatment levels [low and high], replicated six times for a total of 72 microcosms. Monthly tests of total nitrogen and total phosphorus were conducted on a spectrometer and bimonthly analyses of nutrients were conducted on a photometer including nitrates, nitrate nitrogen, ammonia nitrogen and organophosphates. Dissolved oxygen, conductivity and pH were analyzed bimonthly using probes in the field. Preliminary results suggest that there is a differential effect of plant species on phytoremediation, particularly for the remediation of nitrate.