title: The effect of digestion and dewatering on sudden increases and regrowth of indicator bacteria after dewatering.
abstract: Several investigators have reported higher densities of indicator bacteria after dewatering of anaerobically digested biosolids. The increases appear to occur at two points in the biosolids process: the first, referred to as "sudden increase", occurs immediately after dewatering; the second, "regrowth", occurs during storage over longer periods. The objectives of this study were to examine the effect of digestion and dewatering processes on sudden increase and regrowth of fecal coliform and E. coli. Samples were collected from five thermophilic and five mesophilic digestion processes, with either centrifuge or belt filter press dewatering. Sudden increase typically was observed in the thermophilic processes with centrifuge dewatering and was not observed in the mesophilic processes with either centrifuge or belt filter press dewatering. Regrowth was observed in both thermophilic and mesophilic processes with centrifuge dewatering but not belt filter press dewatering.
authors.affiliation: Penn State Harrisburg, Middletown, Pennsylvania, USA.
authors.forename: Yen-Chih
authors.initials: YC
authors.lastname: Chen
authors.forename: Sudhir N
authors.initials: SN
authors.lastname: Murthy
authors.forename: Donald
authors.initials: D
authors.lastname: Hendrickson
authors.forename: Gordon
authors.initials: G
authors.lastname: Araujo
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Higgins
mesh_terms: D001483:Base Sequence; D017931:DNA Primers; D004755:Enterobacteriaceae / Q000254:growth & development*; D004926:Escherichia coli / Q000254:growth & development*; D005243:Feces / Q000382:microbiology; D015203:Reproducibility of Results; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014871:Water Microbiology
chemical_list: D017931:DNA Primers