中文摘要：

采用低强度超声（72～160w）对活性污泥进行辐射处理，研究超声频率、功率和时间对活性污泥混合液细菌总数、微生物相和脱氢酶活性的影响规律。结果表明，活性污泥的细菌总数在初始超声辐射作用10min内上升，之后逐渐下降，但仍维持在同一数量级水平（10^5）；活性污泥的生物相不随短期超声辐射而改变，微型动物在超声辐射过程中比细菌更敏感，活性下降显著，异养菌对低强度超声的耐受性较好；在超声频率35kHz、超声强度0．6W／mL、超声辐射时间10min的条件下，活性污泥脱氢酶活性在短期内有所提高，但过量超声能量的辐射会使其活性下降；超声辐射作用后8h内，脱氢酶活性仍维持在较高水平，24h后脱氢酶活性保持稳定。

英文摘要：

Low power ultrasonic （72 -- 160 W） was used to deal with the activated sludge. The effect of ultrasonic frequency, ultra- sonic power, ultrasonic time on total number of live heterotrophic bacteria, the change of micro fauna and dehydrogenase activity（DHA） was discussed. Results showed that the total number of live heterotrophic bacteria increases in the first 10 min of ultrasonic radiation, and gradually decreases with ultrasonic time but keeps the same order of magnitudes; The biological phase of activity sludge does not change in a short time, and different microorganism has different susceptibility;The activity of micro fauna which is more sensitive to ultrasonic than bacteria decreases significantly;When the optimal parameters are 35 kHz ,0.6 W/mL, 10 rain, respectively, low power ultrasonic makes DHA increase first and decrease with the excessive energy input;DHA remains at a high level in 8 hours and keeps stable after 24 hours.