超声波处理剩余活性污泥促进厌氧消化

Ultrasonic Treatment of Excess Activated Sludge for Improving Its Anaerobic Digestion

用超声波处理剩余活性污泥(简称污泥),考察了污泥絮体结构、污泥中溶解性化学需氧量(SCOD)的变化规律及超声波处理对污泥厌氧消化的影响。实验结果表明,声强大于1 040W/m2时,用超声波处理污泥30m in以上,污泥絮体被打碎,污泥絮体结构遭到严重破坏,污泥中SCOD迅速增加,加速了污泥中有机质的水解反应;声强为2 000W/m2时,用超声波处理污泥60m in,中温((37±1)℃)厌氧消化10d,COD去除率为41%;厌氧消化25d的总产气量比未经超声波处理的污泥总产气量提高了53%;将发酵罐容积放大10倍,经超声波处理的污泥25d累积的总产气量比未经超声波处理的污泥总产气量提高了约25%。

Excess activated sludge was treated by ultrasound wave. The structure of sludge flocs, the change of soluble chemical oxygen demand（SCOD） in sludge and the effect of ultrasonic treatment on sludge anaerobic digestion were studied. The experimental results indicate that：When sludge is treated by ultrasound wave with more than 1 040 W/m^2 of sound intensity for over 30 min, sludge flocs structure is smashed badly, and the SCOD of sludge is increased rapidly, therefore the hydrolytic reaction of organic compounds in sludge is accelerated ; After sludge is treated by ultrasound wave With 2 000 W/m^2 of sound intensity for 60 min and anaerobically digested at moderate temperature （ （37 ± 1 ）℃ ）for 10 d, the removal rate of COD is 41% ;Compared with untreated sludge, the total gas production rate in 25 d of anaerobic digestion is increased by 53% ;When the fermenter volume is scaled up to 10 times,the total gas production rate in 25 d of anaerobic digestion is increased by about 25%.