Performance Analysis of an Integrated Multi-Stage System for Coffee Industry Wastewater Treatment

Wastewater generated during the processing of roasted coffee, including instant coffee, remains relatively unknown in the literature. However, it is characterized by a high organic load and the presence of caffeine, phenolic compounds, and melanoidins. Its properties pose significant environmental and technological challenges, limiting the effectiveness of conventional treatment methods. The research aimed to evaluate the effectiveness of an integrated, multi-stage wastewater treatment system that reflects the process of roasted coffee extraction. The developed technological sequence included biological treatment, activated carbon sorption, membrane filtration, and disinfection using ozone and UV radiation. The experiments used synthetic wastewater containing an extract of roasted coffee beans to simulate the contaminants typically found in instant coffee production and the cleaning of processing equipment. The integrated treatment system enabled the removal of total organic carbon (82.4-95.4%), ammonium nitrogen (0-77.4%), and phosphates (0-39.9%), and a reduction in turbidity of 96.3-99.8% at pH 4.02-7.25. The results confirm the system's high efficiency and its potential for treating complex coffee wastewater, while also highlighting the need for further research into the selection of more favorable process parameters.