Biodegradability Simulation of Coffee Wastewater using Instant Coffee

Abstract

Water minimization in wet process of robusta coffee can improve coffee bean quality while reduce the volume of coffee wastewater. However, this process increases the concentration of organic material in wastewater up to 100% that requires specific handling. High organic matter content in wastewater has potential to be utilized as a source of renewable energy through anaerobic process. The objective of this study is to determine the potential biodegradability of coffee wastewater that has high concentration of organic material into biogas using a composite of microorganisms derived from specific anaerobic reactor. Fluctuated coffee wastewater concentration in coffee cherry processing and limited time of coffee harvested cause limited time to get coffee wastewater with certain concentration. As an approach, this study used instant coffee solution as coffee synthetic wastewater by considering some different characteristics between them. Results of study showed combination of floccular and granular sludge that has broad tropic microorganism composite is the best type of bacteria to convert organic matter into biogas. Moreover, it can overcome acidic environment in coffee wastewater. Since accumulated methane gas reach highest percentages in high concentration of organic matter, it is better to degrade with low rate handling anaerobic.