Bioethanol Production from Coffee Mill Effluent as Potential Renewable Energy

Abstract

Coffee is an important crop for developing countries, particularly in Indonesia. It provides essential income to millions of people, but the wastewater generated threatens the environment and human health. The basic needs in Indonesia are enormous, similar to many other coffee producing areas around the globe. This project has the ability to combat many of the problems facing humans today such as scarcity of potable water and energy supplies for the people that need it most. Coffee producers are all in developing nations and have serious problems disposing of the waste properly because they have no capital available to address the water contamination crisis and little environmental regulatory enforcement. Additionally, the people of rural coffee producing communities have inadequate health care so the availability of clean water is essential to quality of life. Responsible treatment of the wastewater will reduce the impact on the local ecology, and decrease the need for human health care by improving the water quality. This effluent is discarded every day during the processing season to lagoons where it putrefies. We saw these retention ponds and smelled the putrefactions occurring; it ran-off the hill and leached into groundwater. The acids from the fermentation of sugars in the mucilage make the wastewater very acidic, down to a pH of 4.5. The wastewater samples we taken in Ijen plateau in Indonesia during April to August 2014, showed a pH of 4, ammonia nitrogen at >10 mg/L, phosphates of 150 g/L, dissolved oxygen of 0.01 mg/L and BOD >200,000 mg/L. This effluent creates a potential for serious harm to human health and the environment because the contaminated wastewater is either directly discharged to streams or leaches into the groundwater tables like we saw in Ijen region. In developing nations people rely heavily on shallow groundwater tables and surface water for drinking water supply; thus,coffee processing causes great harm to people living within the vicinity.