Proceedings

Wastewater is an effective fertiliser and has been shown in irrigated plot systems to substantially increase biomass production. However, direct generation of woody biomass within constructed wetland beds has not been widely practised or researched. We installed a demonstration system treating a proportion of septic tank effluent at a public rural wastewater treatment plant (110 PE) in North-East Scotland. The system has been operated in a tidal flow configuration and is operated entirely off-grid as there is no electricity supply onsite. Influent and effluent water quality have been monitored for over 5 years for chemical (BOD, nitrate, ammonia, trace elements etc.) and microbiological (E. coli, Total coliforms, microbial biodiversity) parameters. Biomass and plant growth have also been studied along with some preliminary analyses of entomological biodiversity and greenhouse gas emissions (carbon dioxide and methane only to date). This site has provided strong proof of concept information and the results to date are discussed.