Sewage sludge ashes as additives for the cement and ceramics industries

The incineration of sewage sludge produces sewage sludge ash, which has achieved commercial viability in the manufacturing of construction products, thanks to its use in cement manufacturing as an alternative fuel. However, the implementation of construction products incorporating sewage sludge ash is still a ways off, since the scalability is affected by the variability in sludge composition, the presence of undesirable components, and the detrimental effect of ashes on the product’s performance. However, sewage sludge ash-based products are technically feasible and fulfill most common construction product regulations. Environmentally, the presence of heavy metals in sludge and sludge ashes requires further control and monitoring of the leachability characteristics of sewage sludge ash-based products, while the use of sludge as an alternative fuel has the lowest associated environmental benefit from a life-cycle perspective.