Resumen

PIRE-SIERRA, María Carolina; HERNANDEZ-LEON, Jorge Luis; CARRASQUERO-FERRER, Sedolfo José  y  DIAZ-MONTIEL, Altamira Rosa. Effect of an anaerobic treatment on the treatability of tannery wastewater. Rev. Fac. Ing. UCV [online]. 2014, vol.29, n.2, pp.41-50. ISSN 0798-4065.

Biological treatments of industrial wastewater, especially for tannery effluents, do not remove entirely the organic pollutants due to their low biodegradability. For this reason, the aim of this research was to evaluate the effect of an anaerobic pretreatment on the quality of the tannery effluents. The pretreatment of wastewater consisted in storing it in an oxygen-free closed tank, at ambient temperature (31±1 ºC), to be digested anaerobically for periods of 5, 10 and 15 days. The characterization and COD fractionation of the tannery wastewater was done during the first step of this research for raw and pretreated effluents. After that, each effluent was treated biologically using a 2L SBR. Results obtained show that the pretreatment was effective to improve the treatability of tannery wastewater. Statistically, the best result was obtained for a pretreatment of 15 duration days, the COD biodegradable was raised to 64% and the organic nitrogen content was the lowest (87.5 mg·L^-1). The evaluation of the SBR showed the best COD and TKN removal efficiencies when the wastewater was pretreated for 15 days and the cycle in the SBR was 24 hours. The global removals (pretreatment + SBR) were 68.8% for COD, 84.3% for TKN y 99.5% for N-NH₄⁺. The pretreatment removed 39.2% of COD, 25.3% of TKN and 35.4% of N-NH₄⁺, while the SBR contributed with removals of 51.3; 81.4 y 99.0% of COD, TKN and N-NH₄⁺, respectively.

Palabras clave : Anaerobic digestion; SBR; Wastewater; Tannery; Efficiency; Removal.