| Anaerobic granular sludge has the characteristics of strong activity,stable structure and good sedimentation,which can not only keep high sludge volume and good mass transfer effect in the reactor,but also promote the rapid start-up and efficient and stable operation of the reactor.In order to cultivate granular sludge rapidly,the start-up characteristics of the reactor,the formation and characteristics of granular sludge,the influence of granular sludge on the restart of the reactor,the start-up and operation of the newly built dairy wastewater anaerobic reactor and the granular sludge were studied under the conditions of self-made high mass transfer internal circulation anaerobic reactor,pretreatment of inoculated sludge and high load start-up and lifting The results show that:1.Start up characteristics of anaerobic reactor.At the temperature of(35 ± 1)℃,the initial COD concentration is 3000 mg·L-1.When the COD removal rate reaches more than 50%and each index is stable,the load is increased according to 50%of the volume load.After 35 days,the reactor quickly rises from the initial 4 kg·(m3·d)-1 to 30.4 kg·(m3·d)-1.The effluent pH,VFA,ALK and ORP of the reactor are normal,the COD removal rate is stable at more than 90%,and the maximum gas production efficiency is 0.48 m3·(kg·d)-1,it is considered that the reactor startup is completed and the reactor can be started quickly.2.At the same time of reactor start-up,the rapid cultivation of granular sludge was realized successfully.At the 22nd day of reactor start-up,the proportion of granular sludge with particle size>0.2 mm increased from 26.2%to 52.3%,and a large number of visible black granular sludge appeared.On the 47th day of start-up,the proportion of particles>0.2 mm reached 74.6%,the proportion of particles>2.0 mm was 2.3%,the average settling speed increased from 31.8 m·h-1 to 63.7 m·h-1,the value of VSS·TSS-1 increased from 35.3%to 73.6%,the color of mature particles was black,most of them were spherical or ellipsoidal.3.After the mature granular sludge reactor was idle for 30 days,it was restarted at 35℃,HRT of 5.4 h,and volume load of 30.4 kg·(m3·d)-1.The results showed that the COD removal rate of the reactor could be restored to about 90%on the 8th day of start-up,the pH of the reactor effluent kept at about 7.45,the gas production rate increased rapidly from 175 L·d-1 on the 2nd day to 813 L·d-1 and ORP from-350 mV on the 8th day decreased to-475 mV,the reactor was restarted,which indicated that granular sludge had a fast start-up characteristic.4.In the newly built anaerobic reactor for dairy wastewater,by adding the agent for rapid cultivation of granular sludge,the reactor was put into operation for 43 days.The reactor reached the design load,the effluent COD was less than 300 mg·L-1,and the effluent index met the design requirements of the project.On the 60th day of start-up,the granular sludge was cultured successfully in the reactor.The proportion of granular sludge with particle size more than 0.2 mm was 81.4%,the average settling speed of granular sludge was 56 m·h-1,and the value of VSS·TSS-1 increased from 39%to 68.4%.The start-up and operation of the new anaerobic reactor for dairy wastewater and the cultivation of granular sludge were completed. |
PDF Full Text Request