US 12,006,271 B2
Method for sludge dewatering using kitchen waste to synergistically enhance anaerobic biological acidification and low-temperature thermal hydrolysis of excess sludge
Bin Dong, Shanghai (CN); Sisi Chen, Shanghai (CN); Jun Gao, Shanghai (CN); Renjie Chen, Shanghai (CN); Xiangjuan Sun, Shanghai (CN); Zao Yang, Shanghai (CN); and Bing Xue, Shanghai (CN)
Assigned to TONGJI UNIVERSITY, Shanghai (CN)
Filed by Tongji University, Shanghai (CN)
Filed on Jan. 21, 2021, as Appl. No. 17/153,904.
Claims priority of application No. 202010311503.6 (CN), filed on Apr. 20, 2020.
Prior Publication US 2021/0323888 A1, Oct. 21, 2021
Int. Cl. C05F 7/00 (2006.01); C02F 9/00 (2023.01); C02F 11/04 (2006.01); C02F 11/127 (2019.01); C02F 11/13 (2019.01)
CPC C05F 7/00 (2013.01) [C02F 9/00 (2013.01); C02F 11/04 (2013.01); C02F 11/127 (2013.01); C02F 11/13 (2019.01); C02F 2303/06 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A method for sludge dewatering using kitchen waste to synergistically enhance anaerobic biological acidification and low-temperature thermal hydrolysis of excess sludge includes the following steps:
first, uniformly mixing the excess sludge and the kitchen waste for anaerobic biological acidification at 36.5-37.5° C. for 2-4 days to obtain an acidified mixture, wherein a pH value of the acidified mixture is 4-5;
then centrifuging the acidified mixture at a speed of 3000-5000 rpm for 5-10 min to remove a supernatant and then obtain a centrifuged product, wherein a volatile fatty acid content of the supernatant is 800-1500 mg/L, and a chemical oxygen demand (COD) degradation rate of the supernatant is not less than 95%; the supernatant after centrifugally concentrating is returned to a sewage treatment system of a sewage treatment plant as a carbon source;
performing a low-temperature thermal hydrolysis treatment on the centrifuged product for 15-30 min at 100-140° C. to obtain a treated residue;
and after the low-temperature thermal hydrolysis treatment is finished, cooling and dewatering the treated residue to obtain a dewatered sludge cake and a dewatered filtrate.