Dewatering process : mathematical and experimental approach for optimal sludge management in dairy industry

Abstract

The dairy industry is striving to reduce its environmental impact, with a particular focus on sustainable sludge management. A decision-making tool has been developed for Uruguayan dairy companies to optimize sludge management processes. This tool was created by proposing a superstructure and employing mathematical programming, allowing for a comprehensive evaluation of various operational alternatives. The tool evaluated various options, including dewatering, drying, and final disposal. The most cost-effective solution identified was the use of geotextile bags for dewatering, followed by drying and combustion. This alternative proved to be 20% cheaper than the baseline method and also provided a valorization alternative of the waste as a fuel. The tool’s utility was demonstrated through sensitivity analyses. To enhance the tool’s accuracy, an experimental study was conducted to assess sludge dewaterability under pressure. Samples of sludge with varying origins and compositions were analyzed, revealing significant differences in the minimum moisture percentage achieved, despite similarities in the general shape of the curves. These findings enable a better selection of dewatering technologies based on the specific characteristics of each sludge, contributing to more efficient and sustainable management of dairy industry waste.