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.

摘要 本研究针对某肉类加工污水处理厂的污泥开展超声破解试验。本研究采用0至100 MJ/kg总固体（Total Solids, TS）区间内的不同比能输入条件，通过实验室规模实验评估了超声预处理对污泥厌氧生物降解性与过滤性能的影响。研究表明，供能比能为30 MJ/kg TS时可实现高效细胞裂解；超声预处理可显著提升污泥的生物降解性，生化甲烷潜力试验结果亦佐证了这一结论，当比能为30 MJ/kg TS时，甲烷产气量较原始污泥提升2.4倍。超声预处理同时会改变污泥上清液的特性：当比能为30 MJ/kg TS时，污泥上清液中的含油量、总氮与总磷含量分别提升3.8倍、58倍与12倍。此外本研究还发现，即便在极低比能水平下，超声处理仍会对污泥的过滤性能产生负面影响。