The Effect of Different Inoculums on Anaerobic Digestion of Swine Wastewater

CÓRDOBA VERÓNICA; MONICA FERNANDEZ; ESTELA SANTALLA

Journal of Environmental Chemical Engineering

Elsevier

Año: 2015

2213-3437

Methane production from swine wastewater was evaluated by usingthree inoculums: rumen (I1), stabilized swine wastewater (I2) and sewagesludge (I3). Experimental design was based on four treatments byduplicate: T0: swine wastewater as substrate (S) without inoculum (I),T1: S+I1, T2: S+I2 and T3: S+I3 all with 90 (S) -10 (I) % vol with aratio S/I approximately constant (1:0.05). ANOVA test was applied toevaluate the significance of treatments at 95% confidence. After a batchexperiment of 140 days, results indicated that the addition of anyinoculum improved methane production rate and shortened the start-up ofmethane exponential growth stage. I2 and I3 promoted the highestpercentage of organic matter removal (close to 50% in terms of VS andCOD) in relation to control test and the higher methane productionachieving 0.25 L CH4/g VS. The use of rumen (I1) did not improved methaneproduction in the same extent as the other inoculums while organic matterremoval only achieved 15%. The evolution of VFA and alkalinity explaineda two-stage kinetics showing that methanogenic phase could be consideredas the rate limiting step of the global methane production rate.