title: Removal of stigmasterol from Kraft mill effluent by aerobic biological treatment with steroidal metabolite detection.
abstract: Stigmasterol is a phytosterol contained in Kraft mill effluent that is able to increase over 100% after aerobic biological treatment. This compound can act as an endocrine disrupter as its structure is similar to that of cholesterol. The aim of this study was to evaluate the removal of stigmasterol from Kraft mill effluents treated by a moving bed biofilm reactor (MBBR) with steroidal metabolite detection. The MBBR was operated for 145 days, with a hydraulic retention time of 2 days. Stigmasterol and steroidal metabolites were detected by gas chromatography with a flame ionization detector during MBBR operation. The results show that the MBBR removed 87.4% of biological oxygen demand (BOD5), 61.5% of chemical oxygen demand (COD), 24.5% of phenol and 31.5% of lignin, expressed in average values. The MBBR system successfully removed 100% of the stigmasterol contained in the influent (33 µg L(-1)) after 5 weeks of operation. In that case, the organic load rate was 0.343 kg COD m(-3) d(-1). Furthermore, different steroidal compounds (e.g., testosterone propionate, stigmast-4-en-3-one, 5α-pregnan-12-one-20α-hydroxy, 5α-pregnane-3,11,20-trione and 3α-hydroxy-5α-androstane-11,17-dione were detected in the Kraft mill effluent as potential products of phytosterol biotransformation.
authors.affiliation: a Engineering and Environmental Biotechnology Group, Environmental Science Faculty and EULA-Chile Center, University of Concepción , Concepción , Chile.
authors.forename: Soledad
authors.initials: S
authors.lastname: Chamorro
authors.affiliation: a Engineering and Environmental Biotechnology Group, Environmental Science Faculty and EULA-Chile Center, University of Concepción , Concepción , Chile.
authors.forename: Juan P
authors.initials: JP
authors.lastname: Vergara
authors.affiliation: a Engineering and Environmental Biotechnology Group, Environmental Science Faculty and EULA-Chile Center, University of Concepción , Concepción , Chile.
authors.forename: Mayra
authors.initials: M
authors.lastname: Jarpa
authors.affiliation: b Natural Products Chemistry Laboratory, Faculty of Natural and Oceanographic Sciences, University of Concepción , Concepción , Chile.
authors.forename: Victor
authors.initials: V
authors.lastname: Hernandez
authors.affiliation: b Natural Products Chemistry Laboratory, Faculty of Natural and Oceanographic Sciences, University of Concepción , Concepción , Chile.
authors.forename: Jose
authors.initials: J
authors.lastname: Becerra
authors.affiliation: a Engineering and Environmental Biotechnology Group, Environmental Science Faculty and EULA-Chile Center, University of Concepción , Concepción , Chile.
authors.forename: Gladys
authors.initials: G
authors.lastname: Vidal
mesh_terms: D001420:Bacteria, Aerobic / Q000737:chemistry*; D001673:Biodegradation, Environmental; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors; D002677:Chile; D052244:Endocrine Disruptors / Q000032:analysis; D007220:Industrial Waste / Q000032:analysis; D008031:Lignin / Q000032:analysis* / Q000737:chemistry*; D010209:Paper; D028223:Pinus; D013256:Steroids / Q000032:analysis / Q000737:chemistry; D013265:Stigmasterol / Q000032:analysis* / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D052244:Endocrine Disruptors; D007220:Industrial Waste; D013256:Steroids; D008031:Lignin; D013265:Stigmasterol
keywords: Biotransformation; Kraft mill effluent; moving bed biofilm reactor; steroidal metabolites; stigmasterol