Abstract:
This thesis deals with the studies of aerobic biodegradation of hydrocarbon in the combined sludge of oily sludge, and bio-sludge, collected from a dissolved air flotation unit and wastewater treatment unit. The experimentation was conducted in a laboratory, where incubated temperature was 30'~ and incubated in the rotary shaker (200rpm) for 42 days. The results indicated that characteristic of hydrocarbon in oily sludge showed more complex composition than bio-sludge. Oily sludge composed of C,,-C,, while bio-sludge lack of some odd number of hydrocarbon atom such as C,,, C,, and C2,. The results of biodegradation showed that the most appropriate growth of Hydrocarbon Degradation Microorganism (HDM) and the reduction of total hydrocarbon occurred at a concentration of 5% oil, which reduce the total hydrocarbon by 11% on day 42.When concentration of oil was increased, the growth of HDM could adjust themselves better than other microorganisms. The C:N ratio of 10:l by added (NH4),S04, could increase the reduction of total hydrocarbon by 54% on day 21, The addition of nitrogen could stimulate HDM growth by 3 log-cycle. The results of hydrocarbon degradation studied by gas chromatography clearly showed the reduction of some hydrocarbon atom. The study of effect of surfactant on biodegradation, SDS and Triton X-100, inhibited HDM growth as well as the degradation of hydrocarbon. To utilize degraded sludge as coinpost was inappropriate, because original C:N ratio was less than C:N ratio of the compost, In order to use the aerobic sludge system to produce compost, higher C:N ratio should be initially adjusted.