title: Analysis of substrate degradation, metabolite formation and microbial community responses in sand bioreactors treating winery wastewater: a comparative study.
abstract: There is a global need for the implementation of more cost-effective green technologies for the treatment of effluent from wineries. However, systems reliant on microbial biodegradation may be adversely affected by the highly seasonal character of cellar waste. In this study, the biodegradation of two different formulations of winery effluent in sand bioreactors was compared. The degradation of organic substrates and formation of metabolites was monitored by physicochemical analyses of pore water and final effluent samples. Changes in the bacterial community structures were detected using molecular fingerprinting. In wastewater with an overall COD of 2027 mg/L, a formulation with a high concentration of acetate (800 mg COD/L) was more recalcitrant to degradation than a formulation with a high concentration of glucose (800 mg COD/L). Ethanol, glucose and phenolics were degraded preferentially in the deeper layers of the sand bioreactors (average Eh 25 mV) than in the superficial layers (average Eh 102 mV). The redox status also played a pivotal role on the bacterial community composition. The study yielded valuable insight that can be utilized in the design (configuration and operation) of full scale sand bioreactors.
authors.affiliation: Biocatalysis and Technical Biology (BTB) Research Group, Cape Peninsula University of Technology, PO Box 1906, Bellville 7535, South Africa. Electronic address: welzp@cput.ac.za.
authors.forename: P J
authors.initials: PJ
authors.lastname: Welz
authors.affiliation: Biocatalysis and Technical Biology (BTB) Research Group, Cape Peninsula University of Technology, PO Box 1906, Bellville 7535, South Africa; Institute for Microbial Biotechnology and Metagenomics, University of the Western Cape, Bellville 7535, South Africa. Electronic address: Zoom.Palmer@gmail.com.
authors.forename: Z
authors.initials: Z
authors.lastname: Palmer
authors.affiliation: Biocatalysis and Technical Biology (BTB) Research Group, Cape Peninsula University of Technology, PO Box 1906, Bellville 7535, South Africa. Electronic address: shisaacs.30@gamil.com.
authors.forename: S
authors.initials: S
authors.lastname: Isaacs
authors.affiliation: Institute for Microbial Biotechnology and Metagenomics, University of the Western Cape, Bellville 7535, South Africa. Electronic address: bkirby@uwc.ac.za.
authors.forename: B
authors.initials: B
authors.lastname: Kirby
authors.affiliation: Biocatalysis and Technical Biology (BTB) Research Group, Cape Peninsula University of Technology, PO Box 1906, Bellville 7535, South Africa. Electronic address: leroesm@cput.ac.za.
authors.forename: M
authors.initials: M
authors.lastname: le Roes-Hill
mesh_terms: D001673:Biodegradation, Environmental; D019149:Bioreactors; D007220:Industrial Waste / Q000032:analysis*; D059013:Microbial Consortia; D012822:Silicon Dioxide / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000032:analysis*; D014920:Wine
chemical_list: D007220:Industrial Waste; D012822:Silicon Dioxide; D062065:Wastewater
keywords: Biological sand filter; Bioreactor; Constructed wetland; Redox; Volatile fatty acid; Winery wastewater