不同反应条件对污泥水热碳化脱水性能的影响

EFFECT OF REACTION CONDITION ON HYDROTHERMAL CARBONIZATION DEWATERING PERFORMANCE OF SLUDGE

随着城市化进程的加快,我国剩余活性污泥的产生量逐年增加,活性污泥中的胞外聚合物EPS含黏性蛋白类物质并高度亲水,因此破坏污泥絮体、释放和水解黏性有机物是改善污泥脱水性能的有效途径。通过分析水热碳化调理前后污泥比阻(SRF)、黏度(μ)、絮体形态特征及上清液的理化性质,考察了温度、时间以及促进剂Fe_2(SO_4)_3对水热碳化污泥脱水性能的影响。结果表明:反应温度为220℃、反应时间为2 h、Fe_2(SO_4)_3浓度为0. 5 mol/L时的水热碳化处理,污泥的脱水性能最好,比阻和黏度分别比对照组降低了97. 7%和98. 7%。水热碳化的高温高压环境破坏了污泥的絮体,使污泥胶体结构的内聚力降低,污泥的脱水性能得到改善。

With the acceleration of urbanization,the amount of excess activated sludge produced in China has increased rapidly year by year. The extracellular polymer EPS in activated sludge contains viscous protein substances and is highly hydrophilic. Therefore,destroying sludge flocs,releasing and hydrolyzing viscous organic compounds are effective ways to improve sludge dewatering performance. By analyzing the specific resistance to filtration( SRF),viscosity(μ) and floc morphology of sludge and physicochemical properties of supernatant before and after hydrothermal carbonization conditioning,the effect of different temperature,time,and accelerant Fe2( SO4)3 on hydrothermal carbonization dewatering performance were studied. The results showed that when the reaction temperature was 220 ℃,the reaction time was 2 h,and the concentration of Fe2( SO4)3 was 0. 5 mol/L,the highest dewatering performance of the sludge was achieved. The specific resistance to filtration and viscosity were reduced by 97. 7% and 98. 7% compared with the control group. The high temperature and high-pressure environment of hydrothermal carbonization destroyed the flocs of the sludge,reduced the cohesive force of the sludge colloid structure,and improved the dewatering performance of the sludge.