EFFECT OF SULFATE AND NITRATE ON ANAEROBIC OXIDATION OF VOLATILE FATTY-ACIDS IN RABBIT WASTE AT 20-DEGREES-C

Effect of sulfate and nitrate on anaerobic degradation of volatile fat ty acids at 20 degrees C was investigated. Acetate degradation was fou nd to be independent of the presence of sulfate. The addition of sulfa te enhanced propionate/butyrate/valerate oxidation with acetate accumu lation. Sulfate appreciably inhibited (CH4)-C-14 production from H-2+( CO2)-C-14 only in the absence of an exogenous electron donor. The sulf ate-reducing bacterial counts on propionate increased 10-fold in the p resence of sulfate compared to control. Whereas, molybdate and nitrate decreased the volatile fatty acids degradation and methane production by inhibiting both SRB and methanogens.