Integrated constructed wetland systems: design, operation, and performance of low-cost decentralized wastewater treatment systems
Behrends, L.L.; Bailey, E.; Jansen, P.; Houke, L.; Smith, S.
Water Science and Technology a Journal of the International Association on Water Pollution Research 55(7): 155-161
2007
ISSN/ISBN: 0273-1223 PMID: 17506433 Document Number: 608763
Several different types of constructed wetland systems are being used as decentralized treatment systems including surface-flow, subsurface-flow, vertical-flow, and hybrid systems. Archetypical wetland systems have design strengths and weaknesses, and therefore it should be possible to design combined (integrated) systems to optimize a number of important treatment processes. This study provides comparative efficacy data for two integrated wetland treatment systems (IWTS) designed to enhance treatment of medium strength wastewater generated from a pilot-scale intensive fish farm. Results from the twenty eight months study included consistently high removal of COD (840% +) and ammonia nitrogen (93%) in both systems. Initially, phosphorus removal was also high (> 90%) in both systems, but removal efficacy declined significantly over time. Nitrate removal was significantly better in the system that provided sequential aerobic and anoxic environments. Short hydraulic retention times coupled with sustained removal of COD and ammonia indicate that the ReCip components could be a least-cost wastewater treatment technology in the decentralized market sector.