Profiles of fatty acids and triacylglycerols and their influence on the anaerobic biodegradability of effluents from poultry slaughterhouse.

The hydrolysis of effluent from a poultry slaughterhouse containing 800 mg oil and grease (O&G)/L was conducted with 1% (w/v) of an enzymatic pool obtained by solid-state fermentation with the fungus Penicillium restrictum. The chromatographic evaluation of the lipid profile during hydrolysis indicated a higher concentration of acids after 4h of reaction (2954 mg/L), with a predominance of oleic, palmitic, and linoleic acids. Effluent aliquots were collected after 4, 8, and 24h of hydrolysis and tested for anaerobic biodegradation in sequential batches. An adaptation of the biomass was observed, both in the control experiment (with non-hydrolyzed raw effluent) and in the experiments with enzymatically pre-treated effluent. The specific methane production in the control experiment was 0.248 L CH(4)/g COD(consumed), and in the experiment with effluent pre-treated for 4h, this production was 0.393 L CH(4)/g COD(consumed), indicating a higher methane production after enzymatic hydrolysis.

Evaluation of different pre-hydrolysis times and enzyme pool concentrations on the biodegradability of poultry slaughterhouse wastewater with a high fat content.

The effect of different hydrolysis times (4, 8 and 24 h) of a lipase-rich enzymatic preparation (0.1, 0.5 and 1.0% w/v) produced by fungus Penicillium sp. in solid-state fermentation was evaluated on the anaerobic biodegradability of a poultry slaughterhouse wastewater with 800 mg oil and grease [O&G]/L in three sequential batches. The enzymatic pre-treatment of O&G in the experiments with no acclimated sludge had no discernible effect because regardless of the conditions adopted COD removal efficiencies of 95.3% to 98.7% were obtained. However, when the sludge was reused (once or twice) the COD removal efficiencies in the control experiments (69.8% and 53.4%) were considerably lower than in the experiments with hydrolyzed effluent (of 93.8% to 98.4%). Higher values of specific methane production were obtained with 0.1% SEP and 4 h of hydrolysis. After acclimation of the sludge, 19.9% fat was still adhered to the sludge in the control experiment, while the sludge in the experiment with enzymatically pre-treated effluent contained only 8.6% fat, confirming the accumulation of fat when the enzyme pool was not used.