title: Algaculture integration in conventional wastewater treatment plants: anaerobic digestion comparison of primary and secondary sludge with microalgae biomass.
abstract: This study evaluated the feasibility of using microalgae biomass as feedstock for anaerobic digestion together with other biomasses (primary and secondary sludge) normally generated in WWTP. Raw microalgae biomass anaerobic biodegradability (33%) was higher than that of secondary sludge (23%). Thermal pretreatment enhanced 62% and 16% methane yield for Chlorellavulgaris and secondary sludge, respectively. When both substrates were codigested, methane yields remained low. On the other hand, primary sludge supported the highest anaerobic biodegradability (97%) and when combined with thermally pretreated C. vulgaris, methane yields were higher (13-17%) than the ones expected theoretically. Despite the high protein content of those substrates and the high nitrogen mineralization, no ammonia inhibition was detected. Thereby, this study showed that algae biomass is a potential cosubstrate for biogas production together with municipal wastewater sludge.
authors.affiliation: IMDEA Energy, Avda. Ramón de la Sagra 3, 28935 Móstoles, Madrid, Spain; Department of Agricultural Microbiology, Faculty of Agriculture, Zagazig University, 44511 Zagazig, Egypt.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Mahdy
authors.affiliation: IMDEA Energy, Avda. Ramón de la Sagra 3, 28935 Móstoles, Madrid, Spain.
authors.forename: Lara
authors.initials: L
authors.lastname: Mendez
authors.affiliation: IMDEA Energy, Avda. Ramón de la Sagra 3, 28935 Móstoles, Madrid, Spain; CIEMAT, Avda. Complutense, 28040 Madrid, Spain.
authors.forename: Mercedes
authors.initials: M
authors.lastname: Ballesteros
authors.affiliation: IMDEA Energy, Avda. Ramón de la Sagra 3, 28935 Móstoles, Madrid, Spain. Electronic address: cristina.gonzalez@imdea.org.
authors.forename: Cristina
authors.initials: C
authors.lastname: González-Fernández
mesh_terms: D000693:Anaerobiosis; D056804:Biofuels; D018533:Biomass; D002708:Chlorella / Q000254:growth & development / Q000378:metabolism; D006868:Hydrolysis; D008697:Methane / Q000096:biosynthesis; D058086:Microalgae / Q000254:growth & development* / Q000378:metabolism; D008903:Minerals / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D012722:Sewage / Q000382:microbiology*; D013696:Temperature; D062065:Wastewater / Q000382:microbiology*; D018508:Water Purification / Q000379:methods*
chemical_list: D056804:Biofuels; D008697:Methane; D008903:Minerals; D009584:Nitrogen; D012722:Sewage; D062065:Wastewater
keywords: Codigestion; Methane; Microalgae; Primary sludge; Secondary/activated sludge