Effectiveness of treatment and diversity of microbial populations within a constructed wetland treating wastewater.
Constructed wetlands are used as alternative on-site wastewater treatment systems. Microbiological dynamics in constructed wetlands are essential to adequate functioning and efficiency of these systems. The efficacy of wastewater treatment by a large subsurface flow wetland receiving wastewater from a multi-user facility was examined. Real-time monitoring with telemetry was combined with measurement of standard wastewater parameters such as biochemical oxygen demand (BOD5), total suspended solids (TSS), and enumeration of fecal coliforms. Passage of wastewater through the wetland significantly reduced standard wastewater parameters in effluent samples. Heterotrophic bacterial diversity was examined using community level physiological profiling (CLPP) and molecular characterization of 16S ribosomal RNA genes by polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE). Principal component analysis (PCA) indicated distinct grouping between the influent and effluent wastewater populations while DGGE analysis indicated distinct groupings according to cell size.