纯氧曝气活性污泥培养过程中絮体结构变化

采用纯氧曝气序批式反应器(SBR)直接培养、驯化培养活性污泥,运用显微技术分析絮体当量直径(Deq)、规则度(Rd)、孔隙率(Po)和单位悬浮固体内总细丝长度(Ftl)在培养不同时期的变化规律,采用Pearson相关性分析法分析絮体结构参数的相关性.结果表明:污泥直接培养过程中絮体Deq不断增大,驯化培养初期絮体Deq减小,中后期不断增大,驯化培养污泥絮体颗粒较大;污泥直接培养过程中絮体Rd不断减小,驯化污泥絮体Rd变化不大,在0.400~0.520内波动,两种方式培养的絮体规则度值相当;直接培养初期、中期絮体Po随絮体粒径增大而增大,驯化污泥絮体Po初期、后期呈减小趋势,中期呈增大趋势,直接培养法的絮体Po较小;污泥直接培养中、后期出现大量丝状菌,但很快又减少,污泥驯化整个过程中系统内均无大量丝状菌出现.污泥直接培养初期絮体Deq与Po显著正相关,Rd与Deq、Po显著负相关;中期丝状菌作用较大,Ftl与Po、Rd都显著负相关.污泥驯化初期,絮体Deq与Rd、Po均显著正相关,驯化后期Rd起较大作用,与其他参数均显著相关.

Research on the change of floc structure in the process of activated sludge culture with pure oxygen aeration

Activated sludge were cultured by two ways of direct culture and domesticated incubation in sequencing batch reactor(SBR) by pure oxygen aeration, respectively. Microscopic analysis technology was used to analyze the change of Aggregate Equivalent diameter(D_eq), Regularity degree(R_d), Porosity(P_o) and Total filaments length per total suspended solids(F_tl) of the sludge floc. The correlations among sludge floc structure characteristic parameters were drawn by the method of Pearson correlation analysis. The result shows that the size of sludge floc D_eq increases during the process of direct culture, correspondingly, floc D_eq in domesticated incubation decreases during the early phase but constantly increases from the middle to the late phase. larger size of sludge floc particles is obtained in domesticated incubation method. Sludge floc R_d changes little and fluctuates between 0.400 and 0.520 in domesticated incubation, which is similar to floc R_d in direct culture process. Sludge floc P_o increases along with size of floc particles at early and middle stages of direct culture, and decreases at early and late stages of domesticated incubation. The values of floc P_o in direct culture method are low. A great number of filamentous bacteria are observed emerging at middle and late stages of direct culture but then decrease dramatically. Little filamentous bacteria appear in the whole process of domesticated incubation. During the process of direct culture, positive and negative correlations are observed between floc D_eq and floc P_o, and floc R_d and floc D_eq, P_o respectively at the very beginning. Filamentous bacteria plays an important role and sludge floc F_tl are significantly and negatively correlated with floc P_o and R_d at the middle stage in the process of direct culture. At the beginning stage of domesticated incubation, sludge floc D_eq are significantly and positively correlated with sludge floc R_d and P_o, floc R_d plays significant effect at the late period of domesticated incubation and are significantly related with all other parameters.