Premium
Comparison of Mechanical Pretreatment Methods for the Enhancement of Anaerobic Digestion of Pulp and Paper Waste Activated Sludge
Author(s) -
Elliott Allan,
Mahmood Talat
Publication year - 2012
Publication title -
water environment research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.356
H-Index - 73
eISSN - 1554-7531
pISSN - 1061-4303
DOI - 10.2175/106143012x13347678384602
Subject(s) - anaerobic digestion , biogas , pulp and paper industry , waste management , activated sludge , methane , environmental science , chemistry , sewage treatment , engineering , organic chemistry
The conventional anaerobic digestion process, requiring long solids retention times (SRTs) to digest solids, is currently viewed as impractical for the pulp and paper industry because of high capital costs associated with the construction of new digesters. Recent developments in sludge solubilization technology could be promising in reducing digester size, which also allows for the potential use of decommissioned tanks, both of which can reduce the capital cost. Three pretreatment technologies for use with anaerobic digestion were tested on laboratory‐scale to investigate their feasibility. The SRTs in all three digesters systematically decreased from 20 to 3 days. The reference digester was fed waste activated sludge (WAS) to serve as the control at the same SRTs. The other digesters were fed WAS that had been preconditioned using mechanical shearing, sonication, or high‐pressure homogenization technology. Anaerobic digestion with high‐pressure homogenization produced as much methane at 3‐day mean SRT as that from the reference digester operated at 20‐day SRT. Therefore, a new digester can theoretically be 85% smaller than a conventional digester. An added benefit of WAS to methane conversion is the recovery of nutrients nitrogen and phosphorus.