Anaerobic biodegradation of aliphatic compounds in oily sludge under biostimulating conditions to determine sludge optimum composition

Aliphatic hydrocarbons are one of the most important oily sludge compounds that have becomefrequently encountered as environmental pollutants. Bioremediation technologies are also one of the mostpopular techniques to treat many petroleum contaminating compounds. Due to simplicity, lack of oxygensupply and very low amount of biomass production, anaerobic treatment in this study was selected as abioremediating method to reduce aliphatic hydrocarbons of oily sludge. Furthermore in this experimentcowdung was also selected as a biostimulating factor. The experiment was applied for six compositions ofoily sludge, cowdung and water for about 150 days. After this time period, the percentages of aliphaticcompounds and TPH (total petroleum hydrocarbons) reduction were measured and compared with eachother. The results displayed significant relations between concentrations of aliphatic compounds andpercentage of reduction because contaminants concentration affects directly microbial activity andtherefore best degradations were observed in compositions with 3 to 10% oily sludge. High microbialpopulations and cowdung nutrients richness had most important roles in contaminants deterioration. Alsoin this research the best composition of oily sludge in an anaerobic biostimulating process to reach at least90% reduction was proposed between 10 to 15%.

کلیدواژه ها:

Oily sludge ، Aliphatic hydrocarbons ، Bioremediation ، Biostimulation