Microbial processes associated to the decontamination and detoxification of a polluted activated sludge during its anaerobic stabilization.
Xenobiotic compounds accumulate in activated sludge resulting from wastewater treatment plants serving both civil and industrial areas. The opportunity to use anaerobic digestion for the decontamination and beneficial disposal of a contaminated activated sludge was investigated in mesophilic and thermophilic microcosms monitored through an integrated chemical, microbiological and ecotoxicological procedure. The 10 months anaerobic sludge incubation at 35 degrees C resulted in an extensive production of a methane-rich biogas, a marked reduction of pathogenic cultivable bacteria and, importantly, a marked biodegradation of the sludge-carried organic pollutants, including some polychlorinated biphenyls and polycyclic aromatic hydrocarbons, along with a relevant sludge detoxification. The sludge decontamination seemed to occur mostly under methanogenic conditions and was not significantly affected by the addition of yeast extract or molasses. Lower bioremediation and biomethanization yields were observed under thermophilic conditions.
Bertin
Lorenzo
L
DICASM, Faculty of Engineering, University of Bologna, viale Risorgimento 2, I-40136 Bologna, Italy.
Capodicasa
Serena
S
Occulti
Fabio
F
Girotti
Stefano
S
Marchetti
Leonardo
L
Fava
Fabio
F
D000693:Anaerobiosis; D001673:Biodegradation, Environmental; D019149:Bioreactors; D003666:Decontamination; D008697:Methane / Q000378:metabolism; D011078:Polychlorinated Biphenyls / Q000378:metabolism; D011084:Polycyclic Aromatic Hydrocarbons / Q000378:metabolism; D012722:Sewage / Q000737:chemistry / Q000382:microbiology*; D013696:Temperature; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000379:methods*; D018505:Waste Management; D014873:Water Pollutants / Q000378:metabolism* / Q000633:toxicity
D011084:Polycyclic Aromatic Hydrocarbons; D012722:Sewage; D014873:Water Pollutants; D011078:Polychlorinated Biphenyls; D008697:Methane