The Use of Ozone to reduce the Concentration of Malodorous Metabolites in Swine Manure Slurry
摘要
A pilot-scale ozonation system was constructed and operated to reduce the malodours emanating from fresh and stored swine manure slurry. The concentrations of the malodorous bacterial metabolites (phenol,p-cresol,p-ethylphenol and skatole) found in the liquid fraction of the manure slurry were found to increase during three weeks of storage. The fresh and stored manure slurry was ozonated at dosages of 0·25, 0·5, 0·75 and 1·0 g/l. Ozonation eliminated these metabolites from the manure slurry. On the contrary, no useful decrease in the concentration of all the above metabolites was observed after treatment with either nitrogen or oxygen. The odour intensity of the manure slurry was also significantly reduced (P<0·05) after ozonation at a dosage of 0·5 g/l. In contrast, neither stripping with nitrogen nor oxidation using oxygen had a significant effect on the odour acceptability of the mature. The use of hydrogen peroxide and ozone did not offer additional benefit over that obtained with ozone alone. Within the range of 14–25°C, temperature had no effect on the efficiency of ozonation. The ozonated manure did not regain its original malodour after one month of storage subsequent to ozonation.