Anaerobic digestion of wastewater from the production of bleached chemical thermo-mechanical pulp – higher methane production for hardwood than softwood
2016 (English)Article in journal (Refereed) In press
BACKGROUND: Chemical thermo-mechanical pulp (CTMP) mills holds a large biomethane potential in their wastewater. Theirbroadened market has involved increased bleaching and utilization of different raw materials. Therefore, the main aim of thisstudy was to obtain and maintain a well-functioning anaerobic digestion (AD) process, with a high methane yield and totalorganic carbon (TOC) reduction, when digesting CTMP wastewater, from different production protocols including shifts in rawmaterial and bleaching. A lab-scale upflow anaerobic sludge bed (UASB) reactor was used for the tests.RESULTS: The variations in raw material (spruce, birch and aspen) and consequently in TOC-loading (3.6–6.6 kg TOC m−3 andday−1) did not affect the UASB process negatively. Methane production values from 360 to 500 NmL g−1 TOC were obtained,with the highest yield for wastewater from the production of birch- followed by aspen- and spruce pulp. The acetic acid andfiltered-TOC (fTOC) reduction ranged from90 to 95% and 61 to 73%, respectively.CONCLUSIONS: A well-functioning process maintained during shifts in raw material for pulp production which shows that ADis feasible for CTMP mills with a diversified product portfolio. Furthermore, the increased use of hardwood and bleaching willmost likely increase their potential as a biomethane producer.
Place, publisher, year, edition, pages
biogas; wastewater treatment; UASB; CTMP; softwood; hardwood
IdentifiersURN: urn:nbn:se:liu:diva-131782DOI: 10.1002/jctb.4980OAI: oai:DiVA.org:liu-131782DiVA: diva2:1033094
FunderSwedish Energy Agency, 32802–1