Transformation of eucalyptus ash into alkalizing agents for dairy effluent treatment

The increased use of forest biomass fuel for industrial steam generation has resulted in the generation of ash as a common combustion residual. This alkaline oxide-rich ash can be reused for several purposes. This work evaluates the viability of producing a sustainable alkalinizer from biomass fly ash to be used directly in the coagulation step of a wastewater's treatment. The optimization of the important parameters in order to maximize the yield of alkaline compounds was accomplished by using a factorial design (temperature, mass of ash, agitation, and contact time). The study found that temperature did not significantly impact the alkalinity of the extract, meaning it could be produced effectively at room temperature. However, an increase in both the ash mass and the reaction time were essential for achieving higher alkalinity in the final product. When applied in wastewater treatment, the ash-based alkalinizer reduced the required amount of conventional coagulant, despite showing similar effectiveness. This reduction offers potential cost savings and environmental benefits by reducing reliance on chemical alkalinizer, which supports a more sustainable and economical approach to wastewater treatment. On a global scale, this work contributes to the shift toward renewable energy and sustainable waste management. Repurposing biomass ash in this manner reflects principles of the circular economy, providing a greener alternative in wastewater treatment.