• 关键词：剩余污泥  超声波处理  缺氧/好氧消化  胞外聚合物  溶出物  酶活性  活菌数

• 基金项目：广东省教育部产学研合作专项(No. 2008B0905200253)

• 姚炜婷
• 广东工业大学环境科学与工程学院,广州 510006

• 孙水裕
• 广东工业大学环境科学与工程学院,广州 510006

• 郑莉
• 广东工业大学环境科学与工程学院,广州 510006

• 尹光彩
• 广东工业大学环境科学与工程学院,广州 510006

• 李楚华
• 广州市沥滘污水处理厂,广州 510290

• 蔡明山
• 广州市沥滘污水处理厂,广州 510290

• 许燕滨
• 广东工业大学环境科学与工程学院,广州 510006

• 童文锦
• 广东工业大学环境科学与工程学院,广州 510006

• 摘要：为研究超声波促进污泥缺氧/好氧消化的机理,采用最佳超声波参数(超声频率28 kHz,超声密度0.1 W · mL^-1,超声时间15 min,超声间隔时间12 h)与缺氧/好氧消化衔接进行间歇试验,研究了消化过程中污泥胞外聚合物(EPS)组分(蛋白质、多糖、DNA)和相应溶出物占总量的比例,以及酶活性(蛋白酶,脱氢酶)和菌落数的变化趋势,同时以未经超声处理的消化过程作对照.结果表明,在最佳超声波条件下,消化10 d后消化污泥的VSS去除率达到40.14%,高出对照污泥20%,同时释放出大量可溶性物质,说明该超声参数对污泥消化效率有明显的促进作用.超声波-缺氧/好氧消化过程中,超声污泥和对照污泥的EPS组分占总量的比例基本相同,表明超声波促进污泥消化不会引起各组分所占比例的改变.污泥的酶活性随消化时间的增加呈现先增加后减小的变化趋势,消化第4 d达到峰值.消化前5 d,超声污泥的蛋白酶活性大于对照污泥,由于蛋白酶活性的增加和生物反应速度的加快,增加的可溶性物质被大量降解,有机物降解比例提高,因此,超声污泥的VSS去除率大于对照污泥.而脱氢酶活性的变化趋势与对照污泥基本相同,其变化趋势不能用于表征超声波对消化过程的促进作用.污泥的活菌数同样呈先增加后减少的变化趋势,但活菌数的测定方法存在较大误差性,其变化趋势有待进一步的验证.

• Abstract：In order to investigate the sludge anaerobic/aerobic digestion mechanism by ultrasonic sludge treatment, the index proportion of EPS and dissolved substances (polysaccharides, protein and DNA), enzyme activities (protease activity and dehydorgenase activity) were measured in the anaerobic/aerobic digestion by the optimal ultrasonic treatment (28 kHz ultrasonic frequency, 0.1 W · mL^-1 ultrasonic density, 15 min ultrasonic time and 12 h ultrasonic interval time). It showed that the performances of anaerobic/aerobic digestion were greatly improved by ultrasonic treatment, with the removal rate of VSS reaching 40.14% after digestion for 10 days, 20% more than that of the controlled, and at the same time great amount of soluble organics was released. The index proportions of EPS and dissolved substances in the ultrasonic sludge and the control were almost the same, indicating that ultrasonic could promote oxygen/aerobic sludge digestion but would not change the index proportion of EPS and their dissolved substances. The variation trend of enzyme activities increased at the beginning and then dropped off after 10 days' digestion, with the maximum value appearing on the fourth day. The protease activity of ultrasonic sludge was more than that of the controlled during 0~5 d digestion, due to the markedly improved protease activity and the high-speed biological reaction. Organic matter degradation ratio was also improved greatly, leading to the improved VSS removal rate in ultrasonic sludge. While the variation of dehydrogenase activity in ultrasonic sludge was almost the same compared with the controlled, it was therefore unable to represent ultrasonic promotion by sludge anaerobic/aerobic digestibility. The variation trend of sludge bacteria density also increased at the beginning and then dropped off after 10 days’ digestion, but it is controversial for the measurement of bacteria density. Further study is needed.

• Key words：sewage sludge  ultrasonic treatment  anaerobic/aerobic digestion  extracellular polymeric substances  dissolved substances  enzyme activity  bacteria density

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