The 'Energy from Coffee Wastewater' project has proven that it is possible to generate energy, tackle climate change and protect water resources by treating discharges from coffee mills.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/central-american-farmers-generate-energy-coffee-wastewater
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/edie-uk
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/energy
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/waste-energy
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/coffee
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/united-states-america-us
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/water-resources
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/industrial-waste