ULTRASONIC PRE-TREATMENT OF WASTEWATER SLUDGE FROM A MEAT PROCESSING INDUSTRY
Abstract This investigation deals with ultrasonic disintegration of sludge taken from a meat processing wastewater treatment plant. Different specific energy inputs ranging between 0 and 100 MJ/kg Total Solids (TS) were used in the study. The effect of ultrasonic pre-treatment on anaerobic biodegradability and filterability characteristics of sludge were evaluated using lab-scale experiments. 30 MJ/kg TS of supplied energy is efficient for cell lyses. Ultrasonic pre-treatment significantly enhanced the biodegradability of sludge. Biochemical methane potential test results also supported this result. For 30 MJ/kg TS, 2.4 times higher methane production was achieved compared to raw sludge. Sludge's supernatant characteristics were also affected by the ultrasonic pre-treatment. For 30 MJ/kg TS, oil content, total nitrogen and total phosphorus in the sludge supernatant increased by 3.8 times, 58 times, and 12 times, respectively. The other result is that ultrasonic treatment adversely affected filterability characteristics of sludge even for very low specific energy levels.