Proceedings

Nitrogen and phosphorus management within sewage treatment works is problematic since all releases are subject to increasing regulation and hence cost escalation. Any action to improve quality within one part of the treatment system invariably impacts on releases or quality standards elsewhere in the process. A new approach needs to be taken to managing nitrogen within treatment plant to ensure that all elements of the water treatment process are optimised while maintaining costs at sustainable levels.

Short rotation woody crops of willow and poplar have been tested to determine their capacity to renovate raw and partially treated wastewater. The principal benefits of the employing land based treatment include reduced or zero sludge production, low capital and operational costs, reduced energy use within the treatment works, and low management requirement.

This paper discusses how these intensive tree based systems may be employed and provides illustrations of systems currently in operation.

KEY WORDS

Tertiary treatment, biosolids reduction, land treatment, willow, poplar,