Effect of Ce3+ on soluble microbial products production in anaerobic granular sludge digestion

2011 ◽  
Vol 64 (7) ◽  
pp. 1459-1465
Author(s):  
Bo Fu ◽  
Rui Liang ◽  
Qing Xia ◽  
Lili Ding ◽  
Ke Xu ◽  
...  
Keyword(s):  
Extracellular Polymeric Substances ◽  
Oxygen Demand ◽  
Granular Sludge ◽  
Cell Lysis ◽  
Bulk Solution ◽  
Anaerobic Sludge ◽  
Anaerobic Granular Sludge ◽  
Soluble Microbial Products ◽  
Sludge Digestion ◽  
Microbial Products

Upflow anaerobic sludge bed reactors fed on glucose were used to investigate the effects of Ce3+ on soluble microbial products (SMP) production, which is the majority of the residual chemical oxygen demand present in the effluent. It was found that Ce3+ concentration of 0.05 mg/L had no significant effect on the amount of SMP production, whereas that of 1 mg/L led to the increase in SMP production. The molecular-weight distribution and carbohydrate analysis indicated that an increase in SMP production may be partly attributed to the release of extracellular polymeric substances (EPS) into the bulk solution resulted from cerium toxicity, and the nucleic acids analysis suggested that increased cell lysis also contributed to SMP accumulation in the presence of Ce3+. The increase in SMP production in the presence of Ce3+ is possibly a consequence of the release of EPS and increased cell lysis due to cerium toxicity.

scholarly journals Comparison of three types of anaerobic granular sludge for treating pharmaceutical wastewater

2017 ◽  
Vol 8 (4) ◽  
pp. 532-543
Author(s):  
Yibo Wang ◽  
Minquan Feng ◽  
Yonghong Liu ◽  
Yaozhong Li ◽  
Bofei Zhang
Keyword(s):  
Oxygen Demand ◽  
Granular Sludge ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
Anaerobic Granular Sludge ◽  
Pharmaceutical Wastewater ◽  
Abundance And Diversity ◽  
Pva Gel ◽  
Anaerobic Sludge Blanket ◽  
Dominant Bacteria

Abstract Three types of anaerobic granular sludge for treating chemical synthesis-based pharmaceutical wastewater were compared: (1) an up-flow anaerobic sludge blanket (UASB) filled with polyvinyl alcohol (PVA) gel beads (UASB-PVA); (2) a UASB filled with traditional anaerobic granular sludge; and (3) a UASB filled with traditional anaerobic granular sludge and granular active carbon (UASB-GAC). The domestication times for the UASB-PVA, UASB, and UASB-GAC reactors were 30, 47, and 47 days, respectively. When the organic loading rate (OLR) was up to 7 kg chemical oxygen demand (COD)/(m3·d), the COD efficiency of the UASB-PVA, UASB, and UASB-GAC stayed in the range of 69% to 75% (deviation 1.8%), 46% to 69% (deviation 8.6%), and 61% to 73% (deviation 4.0%), respectively. The highest OLRs reached for the UASB-PVA, UASB, and UASB-GAC were 12, 7, and 8 kg COD/(m3·d), respectively. The performance of the UASB-PVA was the best of the three, the UASB-GAC was second, and the UASB was the worst. High-throughput pyrosequencing analysis showed that Levilinea, Syntrophorhabdus, Desulfovibrio and Acetobacterium were the dominant bacteria in the UASB-PVA, UASB, and UASB-GAC reactors’ granular sludge. The abundance and diversity of the microbial community in the UASB-PVA sludge were higher than for the UASB and UASB-GAC granular sludge.

Characterisation of biofilm constituents and their effect on membrane filterability in MBRs

2008 ◽  
Vol 58 (10) ◽  
pp. 1933-1939 ◽  
Author(s):  
T. C. A. Ng ◽  
H. Y. Ng
Keyword(s):  
Structural Characteristic ◽  
Extracellular Polymeric Substances ◽  
Membrane Bioreactors ◽  
Significant Fraction ◽  
Bulk Solution ◽  
Soluble Microbial Products ◽  
Microbial Products ◽  
Solution Changes

Fouling is still one of the main issues in the operation of membrane bioreactors (MBRs). While most attention has been paid to extracellular polymeric substances (EPS) and soluble microbial products (SMP) in the bulk solution, changes in membrane filterability may be more adequately described by the structural characteristic of the fouling layer or biofilm. This study shows that membrane filterability and the rise in TMP is associated to the changes in the biofiom structure, and polysaccharides may be the most significant fraction that affects fouling.

Toxicity of Sulfite and Cadmium to Anaerobic Granular Sludge

1994 ◽  
Vol 29 (4) ◽  
pp. 581-598
Author(s):  
C.F. Shew ◽  
N. Kosaric
Keyword(s):  
Granular Sludge ◽  
Upflow Anaerobic Sludge Blanket ◽  
Shock Load ◽  
Anaerobic Sludge ◽  
Anaerobic Granular Sludge ◽  
Scanning Electron Micrographs ◽  
Bacterial Growth Rate ◽  
Digestion Rate ◽  
Sulfate Reducing ◽  
Load Conditions

Abstract Toxicity of sulfite (Na2SO3) and cadmium (CdCl2) ions to anaerobic granular sludge was investigated in 1.2 litre bench-scale upflow anaerobic sludge blanket (UASB) reactors during process acclimation and shock load conditions. Minimal sulfite toxicity was observed under gradual and shock load conditions at sulfite concentrations of up to 1000 mg S/L if proper acclimation was allowed to occur. No long-term toxic effects were observed although the COD digestion rate was temporarily inhibited by shock load of sulfite. Scanning electron micrographs indicated that more sulfate-reducing bacteria were present in the granules developed in the reactors with sulfite supplement although rod-shaped Methanosaeta-like bacteria were still dominant. High bacterial growth rate was observed in the reactors which were supplied with the feed containing sulfite. The COD digestion rate was inhibited at a cadmium loading rate of 2.4 g Cd per day under both acclimation and shock load conditions. Acclimation did not seem to improve the bacteria to tolerate the toxicity of cadmium. The concentration of free cadmium was very low in the reactors under normal conditions, but increased rapidly when the COD digestion in the reactors ceased. The bacteria could not be reactivated after inhibited by cadmium. When reactors were operated at low specific COD loading rates, more inorganic precipitates were formed inside the granules which consequently settled faster.

Acid Endurance and Sorption of Zn2+ of Anaerobic Granular Sludge Acclimated by Flue Gas Pretreatment Wastewater

2013 ◽  
Vol 634-638 ◽  
pp. 182-186
Author(s):  
Juan Wang ◽  
Qin Zhong
Keyword(s):  
Flue Gas ◽  
Ph Value ◽  
Granular Sludge ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Anaerobic Granular Sludge ◽  
Methanogenic Activity ◽  
Activity Inhibition ◽  
Anaerobic Sludge Blanket

With the aim to use anaerobic granular sludge, the methanogenic activity inhibition and recovery of anaerobic granular sludge from an industrial anaerobic reactor (s1) were investigated by measuring the methane volume at low pH. A lab-scale upflow anaerobic sludge blanket (UASB) reactor was inoculated with s1.s1 was used to remove Zn2+ in wastewater. The results show that activity of s1 is similar when the pH value is 6.5 to 7.0. The methane volume is obviously decreased when the pH value is 6.0. The activity is completely inhibited when the pH value is 4.5. The activity is fully recovered when the pH is above 6.5 and hardly recovers when the pH fell to 4.5. The main Zn2+ removal mechanism is chemical adsorption.

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