Dairy manure wastewater in serial UASB reactors for energy recovery and potential effluent reuse

• Autor(a) principal: Montoya, A. C.V. [UNESP]
• Data de Publicação: 2017
• Outros Autores: Da Mazareli, R. C.S. [UNESP], Da Silva, D. C. [UNESP], De Oliveira, R. A. [UNESP], Leite, V. D.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.1590/0104-6632.20170344s20160297; http://hdl.handle.net/11449/170671
• topic: Bio-energy; High-rate reactors; Livestock waste; Nutrients

This manuscript addresses the use of dairy manure wastewater (DMW) as a substrate for methane production in a high rate system - two serial UASB reactors - and the characterization of the effluent in the different phases of the treatment. Two experimental conditions were applied. In the first, the organic load rate (OLR) was 6.2 gCODtotal L-1 d-1 and the hydraulic retention time (HRT) was 12 days, whereas in experiment 2 they were 14.2 gCODtotal L-1 d-1 and 7.5 days, respectively. The reactors showed a high capacity of removal of COD and solids, i.e., above 71%, which led to bioenergy productivities of 0.55 and 0.73 L CH4 L-1 d-1 in experiments 1 and 2, respectively. The methane yield in UASB1 was 0.19 and 0.08 L CH4g CODrem 1, respectively, in experiments 1 and 2. The methane yield in UASB1 was greater than UASB2, with approximately 70% of methane content in the biogas in this reactor. The effluent characterization showed micro and macronutrients - some in high concentrations, as nitrogen, phosphorous, K, and Fe between 12.1 and 521.4 mg L-1, and others in low concentrations, as Ca, Mg, Zn and Mn between 0.6 and 13 mg L-1. Na was not removed from the UASB systems and its concentration in the effluent was raised to 23.5% in comparison with the substrate.