Effect of liming on the convective drying of urban residual sludges

Sludge liming is largely used in the wastewater industry. This operation, at first realized to stabilize sludge, has also proved to enhance dewatering and to improve the resulting cakes texture. Nevertheless, almost nothing is known about the impact of lime addition on sludge drying behavior. As drying can be considered as a necessary step after mechanical dewatering, it is crucial to evaluate the influence of the sludge pre-treatments on their drying kinetics. This study shows that both pre- and post-liming exert a positive effect on sludge convective drying behavior. The negative impact of sludge destructuring by pumping is also established.