Anaerobic treatment of agro-industrial wastewaters for COD removal in expanded granular sludge bed bioreactor

Document Type: Research Paper

Authors

1 Facultad de Ingeniería. Universidad de Ciencias y Artes de Chiapas. Libramiento Norte Poniente 1150. Lajas Maciel, Tuxtla Gutiérrez, C.P. 29039, Chiapas, México.

2 Departamento de Ingeniería Química y Bioquímica, Tecnológico Nacional de México-Instituto Tecnológico de Tuxtla Gutiérrez, Carretera Panamericana Km 1080, Tuxtla Gutiérrez, C.P. 29050, Chiapas, México.

3 Centro de Investigación y Desarrollo Tecnológico en Energías Renovables, Universidad de Ciencias y Artes de Chiapas, Libramiento Norte Poniente 1150, Lajas Maciel, Tuxtla Gutiérrez, C.P. 29039, Chiapas, México.

4 Catedrática CONACYT, Tecnológico Nacional de México-Instituto Tecnológico de Tuxtla Gutiérrez. Carretera Panamericana Km 1080, Tuxtla Gutiérrez, C.P. 29050, Chiapas, México.

Abstract

Untreated agro-industrial wastewaters are undesirable in the aquatic environment due to the presence of high organic matter contents. However, they may constitute a large potential for biogas production. The present investigation is focused on three laboratory-scale anaerobic expanded granular sludge bed (EGSB) bioreactors, continuously operated for 60 d under mesophilic condition with the aim of exploring the feasibility of treating three most significant agro-industrial wastewaters in Chiapas, Mexico (i.e., cheese whey, vinasse, and coffee-processing wastewater). The EGSB bioreactors were operated with a hydraulic retention time (HRT) of 6 d under stable conditions (i.e., buffer index (BI) of 0.31, 0.34, and 0.03), generating a maximum chemical oxygen demand (COD) removal efficiency of 91, 74, and 96% with an average methane production of 340, 245, and 300 mL/g COD∙d for cheese whey, vinasse, and coffee-processing wastewater, respectively. According to the obtained results, the EGSB bioreactors could be a sustainable alternative to simultaneously solve the environmental problems and to produce bioenergy.

Graphical Abstract

Anaerobic treatment of agro-industrial wastewaters for COD removal in expanded granular sludge bed bioreactor

Highlights

  • Anaerobic EGSB bioreactors were successfully performed for treating different agro-industrial wastewaters.
  • COD removal of upto 91, 74, and 96% for cheese whey, vinasse, and coffee-processing wastewater, respectively.
  • CH4 yield of 340, 245, and 300 mL/gCOD∙d for cheese whey, vinasse, and coffee-processing wastewater, respectively.
  • Biogas generated contained 63.5, 70.8, and 80.3% CH4 for cheese whey, vinasse, and coffee-processing wastewater, respectively.

Keywords


[2] Adams, M.R., Dougan, J., 1987. Coffee Technology, John Wiley and Sons. New York.

[3] Aguirre, P., 2004. Removal mechanisms of organic matter and nutrients in subsurface flow constructed wetlands. New criteria for the design and operation of constructed wetlands. CPET. Barcelona. 17-29.

[8] De Matos, T.A., Lo Monaco, P.A., Pinto, A.B., Fia, R., Fukunaga, D.C., 2001. Pollutant potential of wastewater of the coffee fruits processing. Federal University of Viçosa, Department of Agricultural Engineering, Viçosa-MG, Brazil.

[15] MoEF; Ministry of Environment and Forest, 2003. Water (Prevention and Control of Pollution) Cess (Amendment) Act, 2003. Ministry of Environment and Forests, Government of India, New Delhi.

[16] Pérez, A., Torres, P., 2008. Alkalinity indices for control of anaerobic treatment of readily acidifiable wastewaters. Ing. Compet. 10(2), 41-45.

[19] Robles-González, V., 2011. Integrated treatment of mezcal vinasses for depuration and discharge. Doctoral Thesis. ENCB del IPN. México D.F., México.

[22] Rojas, O., 2004. La alcalinidad como parámetro de control de los ácidos grasos volátiles en digestores UASB. 101-105.

[26] EPA, 2003. CAFO regulations, Federal Register 68(29).

[28] Walkley, A., Black, I., 2006. An examination of the Degtjareff method for determining organic carbon in soils: effect of variations in digestion conditions and of inorganic soil constituents. Soil Sci. 63, 251-263.

[29] WHO, 1995. Guideline for discharge of industrial effluent characteristics. WHO, Geneva. 3, 231-236.