Method for sludge dewatering using kitchen waste to synergistically enhance anaerobic biological acidification and low-temperature thermal hydrolysis of excess sludge

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.