title: Hydrolysis rate constants at 10-25 °C can be more than doubled by a short anaerobic pre-hydrolysis at 35 °C.
abstract: Hydrolysis is the first step of the anaerobic digestion of complex wastewater and considered as the rate limiting step especially at low temperature. Low temperature (10-25 °C) hydrolysis was investigated with and without application of a short pre-hydrolysis at 35 °C. Batch experiments were executed using cellulose and tributyrin as model substrates for carbohydrates and lipids. The results showed that the low temperature anaerobic hydrolysis rate constants increased by a factor of 1.5-10, when the short anaerobic pre-hydrolysis at 35 °C was applied. After the pre-hydrolysis phase at 35 °C and decreasing the temperature, no lag phase was observed in any case. Without the pre-hydrolysis, the lag phase for cellulose hydrolysis at 35-10 °C was 4-30 days. Tributyrin hydrolysis showed no lag phase at any temperature. The hydrolysis efficiency of cellulose increased from 40 to 62%, and from 9.6 to 40% after 9.1 days at 15 and 10 °C, respectively, when the pre-hydrolysis at 35 °C was applied. The hydrolysis efficiency of tributyrin at low temperatures with the pre-hydrolysis at 35 °C was similar to those without the pre-hydrolysis. The hydrolytic activity of the supernatant collected from the digestate after batch digestion of cellulose and tributyrin at 35 °C was higher than that of the supernatants collected from the low temperature (≤25 °C) digestates.
authors.affiliation: Sub-department of Environmental Technology, Wageningen University, P.O. Box 17, 6700 AA, Wageningen, The Netherlands. Electronic address: Lei3.zhang@wur.nl.
authors.forename: L
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Sub-department of Environmental Technology, Wageningen University, P.O. Box 17, 6700 AA, Wageningen, The Netherlands.
authors.forename: R
authors.initials: R
authors.lastname: Gao
authors.affiliation: Sub-department of Environmental Technology, Wageningen University, P.O. Box 17, 6700 AA, Wageningen, The Netherlands.
authors.forename: A
authors.initials: A
authors.lastname: Naka
authors.affiliation: Sub-department of Environmental Technology, Wageningen University, P.O. Box 17, 6700 AA, Wageningen, The Netherlands.
authors.forename: T L G
authors.initials: TLG
authors.lastname: Hendrickx
authors.affiliation: Sub-department of Environmental Technology, Wageningen University, P.O. Box 17, 6700 AA, Wageningen, The Netherlands.
authors.forename: H H M
authors.initials: HHM
authors.lastname: Rijnaarts
authors.affiliation: Sub-department of Environmental Technology, Wageningen University, P.O. Box 17, 6700 AA, Wageningen, The Netherlands.
authors.forename: G
authors.initials: G
authors.lastname: Zeeman
mesh_terms: D000693:Anaerobiosis; D002482:Cellulose; D006868:Hydrolysis; D012722:Sewage; D013696:Temperature
chemical_list: D012722:Sewage; D002482:Cellulose
keywords: Anaerobic digestion; Cellulose; Hydrolysis rate constant; Low temperature; Tributyrin