Wood ash for application in municipal biowaste composting

► We clarify the impacts of pH control by wood ash amendment on a pilot and large scale biowaste composting processes. ► According to our experiments addition of amounts of 4-8% wood ash is sufficient for efficient biowaste composting process and yields a safe end product. ► We scaled up successfully the application of wood ash to an industrial large scale composting plant that was experiencing difficulties with high emission of malodours.