Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6585523 | Chemical Engineering Journal | 2015 | 33 Pages |
Abstract
Cheese whey is considered an important pollutant in dairy wastewaters and an environmental problem to solve. This study aimed to develop a treatment process that combines the advantages of co-digesting cheese whey with manure and the short hydraulic retention time of a high-load anaerobic treatment system by using liquid fractions of dairy manure as a co-substrate. The proposed co-digestion process consists of a one-stage UASB reactor with an external settler and effluent recycling for alkalinity supplementation. Under a constant hydraulic retention time of 2.2Â days and increasing proportion of cheese whey in the feed, the system demonstrated stable operation up to a 75% cheese whey fraction in the feed, with an applied organic loading rate of 19.4Â kg COD mâ3Â dâ1, obtaining a 94.7% COD removal and a volumetric methane production rate of 6.4Â m3 CH4 mâ3Â dâ1. Critical biomass washout was experienced when the cheese whey fraction in the feed was 85%. Operation at a constant 60% cheese whey fraction in the feed mixture enabled stable operation under an organic loading rate of 28.7Â kg COD mâ3Â dâ1 and 1.3Â days HRT, with 95.1% COD removal and a volumetric methane production rate of 9.5Â m3 CH4 mâ3Â dâ1. This new high-load co-digestion method proposed is a promising solution for areas where cheese factories and intensive livestock farming are responsible for environmental pollution caused by unsuitable cheese whey and manure management practices.
Keywords
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Chemical Engineering (General)
Authors
Carlos Rico, Noelia Muñoz, Josefa Fernández, José Luis Rico,