[Characteristics of thermophilic ASBR treating thermal-hydrolyzed sewage sludge].

The characteristics of thermophilic anaerobic sequencing batch reactor (ASBR) treating thermal-hydrolyzed sewage sludge were investigated. The results showed that increasing the OLR (COD) of the thermophilic ASBR treating thermal-hydrolyzed sewage sludge from 7.762 kg/(m3 x d) to 13.106 kg/(m3 x d) lead to the "acidification" of the reactor with the accumulation of the volatile fatty acid (VFA) and the drop of the pH and gas production. This acidification is recoverability. The OLR(COD) of the thermophilic ASBR treating thermal-hydrolyzed sewage sludge can reach to 10 kg/(m3 x d) after the system was recovered. Under the OLR(COD) of 2.523, 4.196, 7.762 and 10.091 kg/(m3 x d), the methane yield (CH4/COD(input)) of thermophilic ASBR were 250, 247, 219 and 187 mL respectively. There are significant linear relationship among OLR and MPR, the methane yield. With the increase of the OLR, the methane production rate increased while the methane yield reduced.

[Three-dimensional excitation emission matrix fluorescence spectroscopic characterization of loosely bound and tightly bound extracellular polymeric substances of sludge].

Three-dimensional excitation emission matrix fluorescence spectroscopy (3DEEM)was applied to characterize the loosely bound extracellular polymeric substances (LB-EPS) and tightly bound extracellular polymeric substances (TB-EPS) extracted from aerobic sludge in wastewater treatment. The results showed that three fluorescence peaks were identified in threedimensional excitation emission matrix fluorescence spectra of the LB-REPS and TB-EPS: peak B (lamda ex/ lamda em = 270-280 nm/345-360 nm), peak C (lamda ex/ lamda em = 330-340 nm/410-430 nm)and peak D (lamda ex/ lamda em = 390 nm/450-470 nm). The peak B was attributed to the protein-like fluorophores, peak C to the visible fulvic-like fluorophore and peak D to the humic-like fluorophore. Results of the peak intensity showed that the major component of the LB-EPS and TB-EPS is protein-like organic matter, then followed by (from high to low): fulvic-like organic matter and humic-like organic matter. The effects of both pH and concentration were significant to the 3DEEMs of LB-EPS and TB-EPS, but the degree is not the same. LB-EPS has the particular chemical structures which are different from the TB-EPS.

[Gradient elevation of temperature startup experiment of thermophilic ASBR treating thermal-hydrolyzed sewage sludge].

Startup experiment was conducted for thermophilic anaerobic sequencing batch reactor (ASBR) treating thermal-hydrolyzed sewage sludge using the strategy of the step-wise temperature increment: 35 degrees C-->40 degrees C-->47 degrees C-->53 degrees C. The results showed that the first step-increase (from 35 degrees C to 40 degrees C) and final step-increase (from 47 degrees C to 53 degrees C) had only a slight effect on the digestion process. The second step-increase (from 40 degrees C to 47 degrees C) resulted in a severe disturbance: the biogas production, methane content, CODeffluent and microorganism all have strong disturbance. At the steady stage of thermophilic ASBR treating thermal-hydrolyzed sewage sludge, the average daily gas production, methane content, specific methane production (CH4/CODinfluent), TCOD removal rate and SCOD removal rate were 2.038 L/d, 72.0%, 188.8 mL/g, 63.8%, 83.3% respectively. The results of SEM and DGGE indicated that the dominant species are obviously different at early stage and steady stage.

[Study on the effects of organic removal by traditional purification process with three-dimensional excitation emission matrix fluorescence spectroscopy].

Fluorescence spectroscopy is widely used to elucidate the origin and structure of organic matters in water substance. Due to its high sensitivity, good selectivity and nondestructive nature, fluorescence technique is suitable to the study of chemical and physical properties of organic matters. Three-dimensional excitation emission matrix fluorescence spectroscopy (3DEEM) was applied to analyze the effects of organic removal by traditional purification process. The results show that 3DEEM is able to disclosure the changes of organic matters in the treatment processes effectively. Traditional purification process can remove some fulvic-like organic matter, but cannot remove it completely. Coagulant sedimentation basically does not have an effect of fulvic-like organic matter removal. The removal proportion of fulvic-like organic matter through filtration is 5%-15%.