高温条件下初始pH值对污泥-餐厨垃圾联合厌氧发酵产氢余物产CH4的影响

污泥-餐厨垃圾厌氧消化产氢产CH₄可将城市有机废弃物转化为可再生能源H₂、CH₄,对实现碳减排发挥着重要作用。通过批式试验探究高温条件下(55±1℃),不同初始pH值对污泥和餐厨垃圾联合厌氧发酵产氢余物产CH₄的影响。研究结果表明:适度地增加产氢余物的碱度会提高产CH₄效能,而过低的初始pH则抑制了产氢余物产CH₄效能。初始pH=8时,CH₄最高浓度(79.08%)、累积产甲烷量(101 mL/g DS)和最大CH₄生产速率(12.21 mL/d)均达到最大。不同初始pH下,总糖和总蛋白质的降解量跟累积产甲烷量呈正相关,其中总蛋白的降解量及降解率均高于总糖。初始pH=8时,总糖和总蛋白质的降解量及降解率最高,分别为6078 mg/L、55.70%和4710 mg/L、69.67%。不同初始pH值下,产氢余物厌氧消化后的pH都趋于7.5左右。

EFFECT OF INITIAL pH VALUE ON METHANE PRODUCTION FROM RESIDUE AFTER ANAEROBIC CO-FERMENTATIVE HYDROGEN PRODUCTION OF SEWAGE SLUDGE AND FOOD WASTE UNDER THERMOPHILIC OPERATION

Simultaneously producing hydrogen and methane via sewage sludge and food waste anaerobic co-digestion, widely regarded as one of the promising methods for renewable energy, plays an important role in carbon emission reduction. This study explored the effect of different initial pH values on the methane production from the residue from anaerobic co-fermentative hydrogen production of sewage sludge and food waste through batch experiments under thermophilic operation(55±1)℃. The results showed that properly increasing the alkalinity of the initial substrate of residue from hydrogen production improved methanogenic performance, while the initial pH=6 inhibited methane production. The highest value of maximum methane concentration(79.08%), cumulative methane yield(101 mL/g DS), and maximum methane production rate(12.21 mL/d) were all found in the test group of initial pH=8. The degradation ratios of total carbohydrate and total protein with different initial pH values were positively correlated with the cumulative methane yield. And total carbohydrate and total protein degradation were also the highest at initial pH=8, with values of 6078 mg/L~55.70% and 4710 mg/L~69.67%, respectively. Among these, the degradation rate of total protein was higher than total carbohydrate. Meanwhile, the pH value after digestion from different initial pH values tended to be 7.5 or so.