超声联合生物酶强化剩余污泥厌氧产酸性能研究

Anaerobic acid production characteristics of excess sludge enhanced by ultrasound and biological enzymes

采用超声和生物酶联用技术处理剩余污泥以促进污泥厌氧发酵产酸,实现污泥资源化。首先,以天津市某污水处理厂二沉池剩余污泥为处理对象,采用单因素实验考察了超声预处理过程中处理时间、超声频率、超声振幅对剩余污泥溶出SCOD的影响,结果表明,超声预处理剩余污泥的最佳处理条件为处理时间5 min、超声频率20 kHz、振幅80%,此条件下,污泥溶出SCOD为407.5 mg/L。之后向经超声处理后的剩余污泥中分别投加污泥质量5%的α-淀粉酶、纤维素酶、溶菌酶和复合酶进行厌氧发酵,以探究生物酶对剩余污泥厌氧消化的影响,结果表明,在温度35℃下,复合酶对于污泥厌氧发酵产酸效果最好,污泥溶出SCOD在第2天增加2384.9mg/L,在第4天产酸量达到最大值1465.8 mg/L,其中乙酸量为1058.6 mg/L,丙酸量为136.0 mg/L。溶菌酶效果优于其他单酶,SCOD第2天增幅达1840 mg/L,在第4天产酸量达1240.4 mg/L,其中乙酸量为406.4 mg/L,丙酸量为524.3 mg/L。

The combination of ultrasound and biological enzyme technology was used to treat excess sludge to promote anaerobic fermentation and acid production,so as to achieve sludge resource utilization.Firstly,a single factor experiment was conducted to investigate the effects of treatment time,ultrasonic frequency,and ultrasonic amplitude on the dissolution of SCOD from the excess sludeg in secondary sedimentation tank of a sewage treatment plant in Tianjin.The results showed that the optimal treatment conditions for ultrasonic pretreatment of excess sludge were 5 minutes of treatment time,20 kHz of ultrasonic frequency and 80%of amplitude.Under these conditions,the dissolution of SCOD from sludge reached 407.5 mg/L.Afterwards,α-amylase,cellulase,lysozyme,and composite enzymes were added to the sludge after ultrasonic treatment,which account for 5%of the sludge,so as to investigate the effect of biological enzymes on anaerobic digestion of excess sludge.The results showed that the composite enzyme had the best effect on anaerobic fermentation of sludge at a temperature of 35℃.The SCOD of sludge increased by 2384.9 mg/L on the second day,and the maximum acid production reached 1465.8 mg/L on the fourth day,with 1058.6 mg/L acetic acid and 136.0 mg/L propionic acid.The effect of lysozyme was superior to other single enzymes,with a SCOD increase of 1840 mg/L on the second day and an acid production of 1240.4 mg/L on the fourth day,including 406.4 mg/L acetic acid and 524.3 mg/L propionic acid.