Project outcomes informing circular economy strategies
1. The quantity of alum sludge and ferric sludge landfilled or recycled annually was quantified.
2. Basic compositional datasets were collated – e.g. dry solids, volatile solids, aluminium, iron, other metals, nutrients and organic matter.
3. The feasibility of an end-of-waste route for recycling coagulant sludge was assessed.
4. A significant number of alternative applications were identified such as reed bed treatment, in constructed wetlands systems, composting for use on agricultural land or as a soil improver.
WRc recommended further research to investigate the technical and economic feasibility of the identified recycling options in collaboration with industry stakeholders.