Toward sustainable and eco-friendly production of coffee: abatement of wastewater and evaluation of its potential valorization

Coffee is one of the most significant beverages consumed worldwide, dating to times immemorial. It plays a pivotal role in several economies owing to its second position in the list of trading commodity, after petroleum. The growing demand for coffee has resulted in a great amount of coffee production and processing and subsequent release of large volumes of wastewater. This wastewater is characterized to have very high chemical oxygen demand and biological oxygen demand with potential to cause environmental pollution thus requiring smart strategies to effectively reduce their load of the wastewater before releasing them into the habitable ambiance. The existing research on coffee wastewater treatment should be critically analyzed for their sustainability and economic viability for them to be commercially used in developing countries for effluent mitigation. This literature review aims to suggest an effective way to treat the wastewater by combining various methods, coupling it with value addition like energy generation. The goal of this review is to provide a direction for future research to integrated treatment with valorization along with a focus on emerging technologies.