Turning Biosolids into Bricks in the Circular Water Economy
In the circular water economy, biosolids from wastewater treatment plants can be used as fertilizer as well as to make bricks!
Biosolids are nutrient-rich organic materials resulting from the treatment of domestic sewage in a treatment facility. When treated and processed, these residuals can be recycled and applied as fertilizer, composted for landscaping use, and used for land rehabilitation as well as for construction activities. There are many initiatives around the world exploring how biosolids can be utilized in a variety of ways, with multiple benefits.
Dŵr Cymru Welsh Water maximizing biosolids on farms
Dŵr Cymru Welsh Water provides cost-effective and sustainable biosolids to farmers within 40 miles of the utility’s advanced anaerobic digestion facilities — Port Talbot, Cardiff, Hereford and Wrexham. To help agricultural customers fully utilize the potential for biosolids on their farms the utility provides a biosolids service that involves soil testing, guidance on utilizing biosolids in the farm system, and on-going support to make sure farmers get the best out of their biosolids. In addition to biosolids enhancing the water holding capacity of the soil, the recycling of biosolids uses less energy than intensive mineral fertilizer production, providing an alternative that reduces carbon footprint.
Melbourne Water’s clay-rich biosolids used in construction
Melbourne Water has reached a major milestone in its biosolids reuse program with the one-millionth ton of biosolids having been recently transported from its Eastern Treatment Plant at Bangholme. While biosolids are commonly reused in agriculture, Melbourne Water has been investigating other uses for its biosolids including use in the production of bricks, cement, and energy. The Eastern Treatment Plant has some biosolids that have a higher percentage of clay (clay-rich), leading to the investigation of reuse opportunities including in construction, roadworks, and rehabilitation earthworks. Already, the clay-rich biosolid materials have been used to rehabilitate a collapsed landfill in outer Melbourne.
RMIT researchers turning biosolids into bricks
Researches from RMIT University in Melbourne have demonstrated that fired-clay bricks incorporating biosolids could be a viable alternative to traditional bricks. The project found that making biosolid bricks only required around half the energy of conventional bricks. In addition, the biosolid bricks were found to have a lower thermal conductivity, transferring less heat to potentially give buildings higher environmental performance. The research also found that brick firing energy demand was reduced by up to 48.6% for bricks incorporating 25% biosolids.
The take-out
It’s up to the imagination as to what biosolids can be used for in the circular water economy.
Join the New LinkedIn Groups:
Blue-Green Infrastructure: https://www.linkedin.com/groups/10412555/
Circular Water Economy: https://www.linkedin.com/groups/10416662/
Nature-Based Solutions: https://www.linkedin.com/groups/10477203
