Characterization of alginate-like exopolysaccharides isolated from aerobic granular sludge in pilot-plant

Lin, Yuemei; Kreuk, Merle de; Loosdrecht, M.C.M. van; Adin, Avner

doi:10.1016/j.watres.2010.03.019

Cited by 297 publications

(145 citation statements)

References 34 publications

Supporting

Mentioning

123

Contrasting

Order By: Relevance

“…NOTE: In order to check if the extracted EPS had ionic hydrogel formation properties, a bead formation test with Ca 2+ ions was used 25 .…”

Section: Ionic Hydrogel Formation Testmentioning

confidence: 99%

“…The precipitate is acidic ALE 25 . The residual fraction was likely EPS which can be solubilized under the extraction conditions, but cannot form a precipitate at pH 2.2.…”

Section: Alginate-like Extracellular Polymer (Ale) Extractionmentioning

confidence: 99%

“…The granulation process has been regarded as a gel-forming phenomenon with glycosides as the gelling agent 4,9,25,28 . Normally, Ca 2+ is one of the most common cations in wastewater.…”

Section: Ionic Hydrogel Formation Testmentioning

confidence: 99%

See 2 more Smart Citations

Extraction of Structural Extracellular Polymeric Substances from Aerobic Granular Sludge

Felz

Al-Zuhairy

Aarstad

et al. 2016

JoVE

View full text Add to dashboard Cite

To evaluate and develop methodologies for the extraction of gel-forming extracellular polymeric substances (EPS), EPS from aerobic granular sludge (AGS) was extracted using six different methods (centrifugation, sonication, ethylenediaminetetraacetic acid (EDTA), formamide with sodium hydroxide (NaOH), formaldehyde with NaOH and sodium carbonate (Na 2 CO 3 ) with heat and constant mixing). AGS was collected from a pilot wastewater treatment reactor. The ionic gel-forming property of the extracted EPS of the six different extraction methods was tested with calcium ions (Ca 2+ ). From the six extraction methods used, only the Na 2 CO 3 extraction could solubilize the hydrogel matrix of AGS. The alginatelike extracellular polymers (ALE) recovered with this method formed ionic gel beads with Ca 2+. The Ca 2+ -ALE beads were stable in EDTA, formamide with NaOH and formaldehyde with NaOH, indicating that ALE are one part of the structural polymers in EPS. It is recommended to use an extraction method that combines physical and chemical treatment to solubilize AGS and extract structural EPS.

show abstract

“…NOTE: In order to check if the extracted EPS had ionic hydrogel formation properties, a bead formation test with Ca 2+ ions was used 25 .…”

Section: Ionic Hydrogel Formation Testmentioning

confidence: 99%

“…The precipitate is acidic ALE 25 . The residual fraction was likely EPS which can be solubilized under the extraction conditions, but cannot form a precipitate at pH 2.2.…”

Section: Alginate-like Extracellular Polymer (Ale) Extractionmentioning

confidence: 99%

See 1 more Smart Citation

Extraction of Structural Extracellular Polymeric Substances from Aerobic Granular Sludge

Felz

Al-Zuhairy

Aarstad

et al. 2016

JoVE

View full text Add to dashboard Cite

show abstract

“…Reagents were obtained from Sigma-Aldrich. Alginate-like exopolysaccharides (ALE) were extracted using the method described by Lin et al [51]. About 1 L of feed and processed sludge was used in the extraction.…”

Section: Extraction Of Eps and Alementioning

confidence: 99%

“…As alginate is an important structural component in (granulated) activated sludge [51], the ALE fractions of the sludge, before and after pre-treatment, were compared (Table 6). The amount of ALE that could be extracted from WAS and ER were in a similar range, i.e.…”

Section: Changes In Ale Upon Wpmentioning

confidence: 99%

Physical and biochemical changes in sludge uponTubifex tubifexpredation

Valk

Khadem

Foreman

et al. 2016

Environmental Technology

View full text Add to dashboard Cite

Worm predation (WP) on activated sludge leads to increased sludge degradation rates, irrespective of the type of worm used or reactor conditions employed. However, the cause of the increased sludge degradation rates remains unknown. This paper presents a comparative analysis of the physical and biochemical aspects of predated sludge, providing insight into the hydrolytic mechanisms underlying WP. To this end, the sessile worm Tubifex tubifex was used as a model oligochaete and was batch cultivated in an 18-L airlift reactor. Predation on activated sludge showed an average reduction rate of 12 ± 3.8%/d versus 2 ± 1.3%/d for endogenous respirated sludge. Sludge predation resulted in an increased release of inorganic nitrogen, phosphate and soluble chemical oxygen demand (sCOD). The sCOD consisted mainly of polysaccharides; however, fluorescence excitation emission matrix spectroscopy analysis also revealed the presence of Tryptophan-protein-like substances. Results suggest that the released polysaccharides contain a protein-like element. Additionally, soluble iron increased slightly in concentration after WP. The extent of hydrolysis seemed to reach an average plateau of about 40% volatile solids (VS) reduction after 4 days, which is substantially higher than the 29% VS reduction for endogenous decay of activated sludge after 30 days. Furthermore, T. tubifex predominantly consumed the protein fraction of the extracellular polymeric substances. Results suggest that that the worms specifically target a fraction of the sludge that is predominantly biodegradable under aerobic conditions, albeit at significantly higher degradation rates when compared to the endogenous decay of waste activated sludge. ARTICLE HISTORY

show abstract