2. Center for the Study of Industrial Biotechnology (CEBI), Universidad de Oriente (UO), Patricio Lumumba s/n, Santiago de Cuba, CP 90500, Cuba.
3. Center for the Study of Energy and Process, University of Sancti Spiritus, Martyrs Avenue, No. 360, Sancti Spiritus, CP 60100, Cuba.
4. Superior School of Technical Agricultural Engineers (ETSIA), Polytechnic University of Madrid (UPM) Avda Puerta de Hierro, 2 L10, CP 28040 Madrid, Spain.
5. Institute of Engineering, National Autonomous University of Mexico (UNAM), Avenida Universidad 3000, Mexico DF Mexico.
The present work shows the results obtained in the anaerobic digestion of coffee wet wastewater processing. The anaerobic reactors were operated with two configurations, single-stage and two-stage in mesophilic-controlled conditions. The effect of both organic loading rate (OLR) and reactor configuration in the anaerobic digestion of coffee wet wastewater was investigated. The OLR values considered in the single-stage system varied in arrange of 3.6-4.1 kgCOD m-3 d-1. The acidogenic reactor of the two-stage system was fed at a rate of 11 kgCOD m-3 d-1, whereas the methanogenic reactor load varied in the range of 2.6-4.7 kgCOD m-3 d-1. For the same HRT and OLR global conditions, the two-stage system showed the best results in the treatment of this type of wastewater. The present study suggests that the experimental design technique is a suitable tool to the investigation of the wastes anaerobic treatment technologies.
Keywords: Single-stage and two-stage anaerobic digestion, coffee wet wastewater, UASB reactor, acidogenic reactor, methanogenic reactor, experimental design technique