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Effect of the generation and physical-chemical characterization of swine and dairy cattle slurries on treatment technologies

Abstract:

Differences in biodegradability can affect the treatment of slurry before its use in spraying. The objective of this study was to evaluate the effect of the generation and physical-chemical characterization of swine and dairy cattle slurries on different biological treatment technologies. This research involved monthly sampling (number/composition) for 1 year of 24 swine farms (16%), cattle farms (38%), and mixed swine and cattle farms (46%). The results obtained showed differences in feeding (3 l water kg-1 food for cattle and 5 l water kg-1 food for swine) and assimilation (0.6 kg food kg -1 milk produced and 3 kg kg-1weight gain), which may influence the generation of slurry (57 l animal-1d-1 in cattle and 31 l animal-1 d-1 in swine) and its composition. In addition, the composition of swine slurry [23 g chemical oxygen demand (COD) l-1, 3 g total nitrogen (TN)l-1] issignificantly different (P < 0.01) to cattle slurry (4 g COD l -1, 0.3 g TN l-1). Finally, the composition and the S index applied to swine slurry [COD N-1 = 8, biological oxygen demand (BOD)5 COD-1 = 0.3, S index > 0] and cattle slurry (COD N -1 = 16, BOD5 COD-1 = 0.6, S index < 0) show a difference on the biodegradability of both slurries. Suitability of anaerobic and aerobic treatment was assessed based on the findings. © 2013 The Author(s).