title: Reuse of recalcitrant-rich anaerobic effluent as dilution water after enhancement of biodegradability by Fenton processes.
abstract: Anaerobic digestion is used to treat effluents with a lot of organics, such as molasses distillery wastewater (MDW) which is the effluent of bioethanol production from molasses. The raw MDW requires a lot of dilution water before biodigestion, while the digested MDW has high level of recalcitrants which are problematic for its discharge. This study investigated ferric coagulation, Fenton, Fenton-like (with ferric ions as catalyst) processes and their combinations on the biodegradability of digested MDW. The Fenton and Fenton-like processes after coagulation increased the MDW biodegradability defined by (BOD5/COD) from 0.07 to (0.4-0.6) and saved 50% of H2O2 consumed in the classic Fenton process. The effluent from coagulation coupled to a Fenton-like process was used as dilution water for the raw MDW before the anaerobic digestion. The process was stable with volumetric loading of approx. 2.7 g COD/L/d. It resulted in increased overall biogas recovery and significantly decreased the demand for the dilution water.
authors.affiliation: Technische Universität Berlin, Department of Environmental Technology, Chair of Environmental Process Engineering, Secr. KF 2, Straße des 17. Juni 135, D-10623, Berlin, Germany; Moi University Main Campus, Faculty of Technology, P.O. Box 3900, Eldoret, Kenya. Electronic address: milton.m.marimi@campus.tu-berlin.de.
authors.forename: Milton M
authors.initials: MM
authors.lastname: Arimi
authors.affiliation: Technische Universität Berlin, Department of Environmental Technology, Chair of Environmental Process Engineering, Secr. KF 2, Straße des 17. Juni 135, D-10623, Berlin, Germany. Electronic address: yongjun.zhang@tu-berlin.de.
authors.forename: Yongjun
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Moi University Main Campus, Faculty of Technology, P.O. Box 3900, Eldoret, Kenya.
authors.forename: Saul S
authors.initials: SS
authors.lastname: Namango
authors.affiliation: Technische Universität Berlin, Department of Environmental Technology, Chair of Environmental Process Engineering, Secr. KF 2, Straße des 17. Juni 135, D-10623, Berlin, Germany.
authors.forename: Sven-Uwe
authors.initials: SU
authors.lastname: Geißen
mesh_terms: D001421:Bacteria, Anaerobic / Q000378:metabolism*; D001673:Biodegradation, Environmental; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D062065:Wastewater; D014871:Water Microbiology; D018508:Water Purification / Q000191:economics* / Q000379:methods
chemical_list: D006861:Hydrogen Peroxide; D007501:Iron; D062065:Wastewater; C045076:Fenton's reagent
keywords: Coagulation; Melanoidin; Oxidation; Vinasse