Insight into correlation of advanced nitrogen removal with extracellular polymeric substances characterization in a step-feed three-stage integrated anoxic/aerobic biofilter system

2021 ◽  
pp. 151418
Author(s):  
Zilong Hou ◽  
Xin Zhou ◽  
Wenyi Dong ◽  
Hongjie Wang ◽  
Huaguang Liu ◽  
...  
Keyword(s):  
Nitrogen Removal ◽  
Extracellular Polymeric Substances ◽  
Advanced Nitrogen Removal ◽  
Insight Into

Archaeal biofilms: widespread and complex

2013 ◽  
Vol 41 (1) ◽  
pp. 393-398 ◽  
Author(s):  
Sabrina Fröls
Keyword(s):  
Biofilm Formation ◽  
Extracellular Polymeric Substances ◽  
Bacterial Species ◽  
Surface Adhesion ◽  
Form Complex ◽  
Abiotic Surfaces ◽  
Archaeal Species ◽  
Physical And Chemical ◽  
Insight Into ◽  
Mixed Communities

Biofilms or multicellular structures become accepted as the dominant microbial lifestyle in Nature, but in the past they were only studied extensively in bacteria. Investigations on archaeal monospecies cultures have shown that many archaeal species are able to adhere on biotic and abiotic surfaces and form complex biofilm structures. Biofilm-forming archaea were identified in a broad range of extreme and moderate environments. Natural biofilms observed are mostly mixed communities composed of archaeal and bacterial species of various abundances. The physiological functions of the archaea identified in such mixed communities suggest a significant impact on the biochemical cycles maintaining the flow and recycling of the nutrients on earth. Therefore it is of high interest to investigate the characteristics and mechanisms underlying the archaeal biofilm formation. In the present review, I summarize and discuss the present investigations of biofilm-forming archaeal species, i.e. their diverse biofilm architectures in monospecies or mixed communities, the identified EPSs (extracellular polymeric substances), archaeal structures mediating surface adhesion or cell–cell connections, and the response to physical and chemical stressors implying that archaeal biofilm formation is an adaptive reaction to changing environmental conditions. A first insight into the molecular differentiation of cells within archaeal biofilms is given.

Extracellular polymeric substances and dewaterability of waste activated sludge during anaerobic digestion

2014 ◽  
Vol 70 (9) ◽  
pp. 1555-1560 ◽  
Author(s):  
Fenxia Ye ◽  
Xinwen Liu ◽  
Ying Li
Keyword(s):  
Anaerobic Digestion ◽  
Activated Sludge ◽  
Extracellular Polymeric Substance ◽  
Extracellular Polymeric Substances ◽  
Waste Activated Sludge ◽  
Sludge Dewatering ◽  
Capillary Suction ◽  
Relationship Analysis ◽  
The Relationship ◽  
Insight Into

Anaerobic digestion of waste activated sludge was conducted to gain insight into the mechanisms underlying change in sludge dewaterability during its anaerobic digestion. Unexpectedly, the results indicated that sludge dewatering properties measured by capillary suction time only deteriorated after 10 days of anaerobic digestion, after which dewaterability recovered and remained stable. The loosely bound extracellular polymeric substance (LB-EPS) content increased three-fold after 20 days of anaerobic digestion, and did not change significantly during the remaining 30 days. The tightly bound EPS (TB-EPS) content reduced slightly after 20 days of anaerobic digestion, and stabilized during the last 30 days. Polysaccharides (PS) and proteins (PN) content in LB-EPS increased after 10 days of anaerobic digestion. However, PS and PN contents in TB-EPS decreased slightly. The relationship analysis showed that only LB-EPS correlated with dewaterability of the sludge during anaerobic digestion.

Advanced nitrogen removal via nitrite from municipal wastewater in a pilot-plant sequencing batch reactor

2009 ◽  
Vol 59 (12) ◽  
pp. 2371-2377 ◽  
Author(s):  
Q. Yang ◽  
X. H. Liu ◽  
Y. Z. Peng ◽  
S. Y. Wang ◽  
H. W. Sun ◽  
...  
Keyword(s):  
Carbon Source ◽  
Process Control ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Pilot Plant ◽  
Sequencing Batch Reactor ◽  
Municipal Wastewater ◽  
Batch Reactor ◽  
Nitrite Accumulation ◽  
Advanced Nitrogen Removal

To obtain economically sustainable wastewater treatment, advanced nitrogen removal from municipal wastewater and the feasibility of achieving and stabilizing short-cut nitrification and denitrification were investigated in a pilot-plant sequencing batch reactor (SBR) with a working volume of 54 m3. Advanced nitrogen removal, from summer to winter, with effluent TN lower than 3 mg/L and nitrogen removal efficiency above 98% was successfully achieved in pulsed-feed SBR. Through long-term application of process control in pulsed-feed SBR, nitrite accumulation reached above 95% at normal temperature of 25°C. Even in winter, at the lowest temperature of 13°C, nitrite was still the end production of nitrification and nitrite accumulation was higher than 90%. On the basis of achieving advanced nitrogen removal, short-cut nitrification and denitrification was also successfully achieved. Compare to the pulse-feed SBR with fixed time control, the dosage of carbon source and energy consumption in pulsed-feed SBR with process control were saved about 30% and 15% respectively. In pulsed-feed SBR with process control, nitrogen removal efficiency was greatly improved. Moreover, consumption of power and carbon source was further saved.

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