Challenges for the development of advanced constructed wetlands technology

Widespread demands for improved receiving water quality, water reclamation and reuse require the implementation of advanced catchment management techniques. Increasingly, management options for reducing the impact of effluent and run-off on receiving waters involve the application of constructed wetlands (CWS) technology. Current applications of CWS technology include the treatment of primary settled and secondary treated sewage, tertiary effluent polishing, disinfection, urban and rural run-off management, toxicant management, land-fill and mining leachate treatment, sludge management, industrial effluent treatment, enhancement of instream nutrient assimilation, nutrient removal via biomass production and export and groundwater recharge. Major CWS research and development work needs to be directed at refining our understanding of nutrient immobilisation and other pollutant processing mechanisms and the application of this knowledge to the development of advanced wetland designs. Concomitantly, the 'user-friendliness' of wetland design criteria and the wetland planning process needs to be enhanced. In the first instance this is being addressed by the development and refinement of information databases and decision support systems so as to foster the employment of the most environmentally and economically advantageous systems for a given application and locality.