超声波促进城市生活污泥缺氧/好氧消化的研究

A study on enhancing anoxic/aerobic digestion of municipal sewage sludge by ultrasound

本研究将超声波预处理引入城市生活污泥缺氧/好氧消化工艺中,自主设计了容积为30 L的生活污泥超声波-缺氧/好氧消化中试系统并用以实验研究。超声波预处理的参数为超声频率28 kHz,声能密度0.15 W/mL,超声时间10min,超声间隔12 h,污泥超声比例30%。结果表明,引入超声预处理后,缩短了污泥的稳定时间,提高了污泥的消化效率。污泥消化10 d就已经达到了稳定标准,比未引入超声预处理时缩短了12 d,而MLVSS最大去除率提高了11%,达到了55.10%。超声波的引入,对污泥缺氧/好氧消化系统中污泥上清液溶解性COD(SCOD)的变化趋势影响比较明显,而对上清液的pH、氨氮和TP的变化趋势没有明显影响。

Ultrasonic pretreatment was introduced to anoxic/aerobic digestion of municipal sewage sludge in this study.A reactor with a volume of 30 L was designed and specialized for the ultrasonic anoxic/aerobic digestion.The pretreatment tests were carried out under the following conditions： ultrasonic frequency of 28 kHz,ultrasonic density of 0.15 W/mL,ultrasonic time of 10 min,ultrasonic interval of 12 h,and pretreated sludge proportion of 30%.The results show that the ultrasonic pretreatment can reduce the digestion time of sludge and improve the digestion efficiency.Sludge reached the discharge standard after 10 days＇ digestion,12 days shorter than that without ultrasonic pretreatment.The maximum removal rate of MLVSS increased by 11%,up to 55.10%.In addition,the ultrasonic pretreatment had a significant effect on the change trend of soluble COD（SCOD） of supernatant digestion liquid,but a little on that of pH,ammonia nitrogen and TP.