STATISTICAL COMPARISON OF BIOGAS PRODUCTION FROM SELECTED DOMESTIC ANIMAL DUNGS

Abstract

Slurries (four per dung) of cattle, camel, sheep, goat and horse dung were prepared by mixing 200g dung with 800cm3 of water. The slurries were digested anaerobically over a retention period of 13 weeks at an average temperature of 31.8°c. The average total biogas yields were found to be 14.10, 16.30,23.08,24.66 and 29.22 dm3, respectively. That is, horse dung> goat dung> sheep dung> camel dung> cattle dung. Analysis of variance test indicates that the difference between the mean biogas yields of the dung is highly significant. However, pairwise comparison of the mean yields using the Least Significant Difference (LSD) and the Duncan's Multiple Range (DMR) tests show that the difference in mean yields between horse, goat and sheep dung is not significant at the 1% level of significance. Also, that between goat and sheep, as well as came) and cattle dung is not significant at the 5% level of significance. But, while LSD indicates that the difference between the mean yields of sheep and camel is significant at 5% level, the DMR test suggests otherwise. The DMR test is considered to be more accurate.