Floc-Forming Substances Extracted from Activated Sludge with Ammonium Hydroxide and EDTA Solutions

1985 ◽  
Vol 17 (4-5) ◽  
pp. 517-528 ◽  
Author(s):  
T. Sato ◽  
Y. Ose
Keyword(s):  
Molecular Weight ◽  
Activated Sludge ◽  
Sequential Extraction ◽  
Ammonium Hydroxide ◽  
Low Molecular Weight ◽  
Metallic Ions

The authors attempted to extract the floc-forming substances by sequential extraction with NH4OH and EDTA solutions from activated sludge. Some fractions had the capacity for floc formation in acidic ranges and some of the fractions were further fractionated by Sephadex G-50. There is a possibility that low molecular weight substances, except metallic ions related to floc formation and floc-forming substances in activated sludge are not limited to one special substance.

Photosynthesis and metabolism of marine algae. VIII. Incorporation of 14C into the polysaccharides metabolized by Fucus vesiculosus during pulse labeling experiments

1972 ◽  
Vol 50 (1) ◽  
pp. 191-197 ◽  
Author(s):  
R. G. S. Bidwell ◽  
Elizabeth Percival ◽  
Berit Smestad
Keyword(s):  
Molecular Weight ◽  
Sequential Extraction ◽  
Marine Algae ◽  
Alginic Acid ◽  
Fucus Vesiculosus ◽  
Fresh Medium ◽  
Low Molecular Weight ◽  
Acid Extract ◽  
Highly Active ◽  
Residual Material

Samples of Fucus vesiculosus fronds were allowed to assimilate 14CO2 for 10 min and 3 h. In a second experiment fronds were allowed to grow for 10 min in 14CO2 and were then transferred to fresh medium containing 12CO2. Samples were taken immediately, after 30 min, and after 2 h. Sequential extraction and fractionation of the polysaccharides from each of the five samples gave 14C-labeled laminaran, xylogalactofucoglucuronan (A), xyloglucuronogalactofucan (B) (these polysaccharides are named in the order of the increasing proportions of their constituent sugars), fucoidan (C), alginic acid, and residual polysaccharide material containing mainly glucose with some galactose. The activities of each of the polysaccharides, the residual material, and their constituent sugars were measured. Highly active low molecular weight carbohydrates, present in the acid extract, are the suggested precursors of the polysaccharides. The fucose-containing polysaccharides represent the extremes of a family of polymers; it is postulated from these studies that (A) is transformed into fucoidan via polysaccharide (B) in this alga.

Effect of acclimating saccharides on the activated sludge bacterial population: composition abnormality of activated sludge acclimated to glucose

1998 ◽  
Vol 37 (4-5) ◽  
pp. 99-103
Author(s):  
Yuu Ubukata ◽  
Susumu Takii
Keyword(s):  
Molecular Weight ◽  
Chemical Composition ◽  
Activated Sludge ◽  
Bacterial Population ◽  
Municipal Sewage ◽  
Appreciable Amount ◽  
Low Molecular Weight ◽  
Population Composition ◽  
Gram Positive ◽  
Gram Negative

The question of whether the substitution of glucose for starch in municipal sewage as an acclimating saccharide for activated sludge (AS) in the laboratory is valid was investigated using activated sludges acclimated to glucose (G-AS) and dextrin (D-AS), since the bacteria responsible for starch (dextrin) removal in D-AS are verified to take up maltose instead of glucose during dextrin removal. In G-AS, polysaccharides are the major reserve materials, and large amounts of residual organic materials (ROM) are excreted from the AS. In contrast, in D-AS, about half of the reserve materials are low molecular weight saccharides, and no appreciable amount of ROM was detected. It is considered that most bacteria responsible for the removal of dextrin and glucose are Gram-negative and Gram-positive, respectively, based on the results of the chemical composition of AS and the type of reserve saccharide. As a result, in laboratory-scale AS processes, maltose (disaccharide) or dextrin (polysaccharide), instead of glucose (monosaccharide), should be used as a substitute for starch.

The Removal of Chlorinated Organics from Conventional Pulp and Paper Wastewater Treatment Systems

1992 ◽  
Vol 26 (1-2) ◽  
pp. 417-425 ◽  
Author(s):  
C. W. Bryant ◽  
J. J. Avenell ◽  
W. A. Barkley ◽  
R. N. Thut
Keyword(s):  
Molecular Weight ◽  
Wastewater Treatment ◽  
Activated Sludge ◽  
High Molecular Weight ◽  
High Performance ◽  
Treatment Plant ◽  
Low Molecular Weight ◽  
Pulp Mills ◽  
Minimal Impact ◽  
Wastewater Treatment Systems

A two-year survey of adsorbable organic halide (AOX) removals was conducted for eight full-scale wastewater treatment systems operated at pulp mills in North America. The resulting AOX database, one of the most comprehensive currently available, supports several significant findings. AOX removals averaged 46% for the two activated sludge systems and 34% for the five aerated stabilization basins (ASBs). Both the activated sludge facilities and ASBs averaged removing over half of the influent low molecular weight AOX. The average removal of high molecular weight AOX varied among mill sites from 1% to 47% and was not correlated with the type of treatment process used. The best-performing treatment facility, located at a sulfite mill receiving nearly 100% hardwood furnish and using an activated sludge treatment system, was able to consistently remove 53% of the AOX, 62% of the low molecular weight AOX, and 47% of the high molecular weight AOX in bleaching wastewaters. Factors responsible for this high performance are not currently understood. Effluent AOX was strongly correlated (R2 = 0.90) to the influent loading for ASBs. In-mill improvements such as the use of oxygen and peroxide as well as chlorine dioxide substitution reduce influent AOX loading, apparently with minimal impact on treatment plant removal efficiency.

scholarly journals Comparison of ΣLMW Utilization Rate from Saline Wastewater in SBR Reactors with Granular and Flocked Activated Sludge

Proceedings ◽  
2019 ◽  
Vol 16 (1) ◽  
pp. 17
Author(s):  
Ofman ◽  
Skoczko
Keyword(s):  
Molecular Weight ◽  
Polycyclic Aromatic Hydrocarbons ◽  
Activated Sludge ◽  
Aromatic Hydrocarbons ◽  
Oxygen Demand ◽  
Biological Oxygen Demand ◽  
Utilization Rate ◽  
Low Molecular Weight ◽  
Saline Wastewater ◽  
Polycyclic Aromatic

Paper discuses changes in utilization rate of Low Molecular Weight polycyclic aromatic hydrocarbons PAHs in sequencing bath reactors (SBR) operating with flocked and aerobic granular activated sludge. Studies were carried out in laboratory scale SBR reactors filled with model wastewater characterized by salinity at level 4.00 g·dm−3. Wastewater inflowing to laboratory reactors was characterized by varying biological oxygen demand (BOD) load in the range of 0.05–1.60 kg BOD·kg−1·d−1.

Characterization of a Biologically Treated Wastewater from Oil Reclaiming: Recording of Low Molecular Weight Organics and Estimation of Humic Substances

1994 ◽  
Vol 29 (9) ◽  
pp. 195-198 ◽  
Author(s):  
H. Gulyas ◽  
M. Reich ◽  
I. Sekoulov
Keyword(s):  
Molecular Weight ◽  
Humic Acid ◽  
Activated Sludge ◽  
Treated Wastewater ◽  
Nitrogen Compounds ◽  
Low Molecular Weight ◽  
Activated Sludge Process ◽  
Wastewater Samples ◽  
Acid Esters

Wastewater originating from oil reclaiming (COD about 300 mg/l, TOC about 70 mg/l) which was pretreated by equalization, neutralization, adsorption to activated sludge from a publicly owned treatment work, flocculation, and flotation and finally oxidized in an activated sludge process was analyzed for humic acids and gas chromatographically detectable organic compounds. The humic acid concentration was estimated to represent about 15% of the COD. Hydrocarbons were detected in activated sludge, but no hydrocarbons were identified gas chromatographically. In the two analyzed wastewater samples ethers (mainly containing polyethoxy structures), carboxylic acids and carboxylic acid esters were found. In one sample several nitrogen compounds (amines and amides) were detected. Except for l,l'-oxybis-(2-methoxy)-ethane, which was a constituent of both samples, the organic gas chromatographically detectable compounds differed completely from sample to sample. This is obviously due to changing composition of the processed spent oils.

Improved Sludge Dewatering by Dual Polymer Conditioning

1993 ◽  
Vol 28 (1) ◽  
pp. 53-57 ◽  
Author(s):  
P. R. Senthilnathan ◽  
Roger G. Sigler
Keyword(s):  
Molecular Weight ◽  
Pharmaceutical Industry ◽  
Activated Sludge ◽  
High Molecular Weight ◽  
Full Scale ◽  
Screening Methods ◽  
Low Molecular Weight ◽  
Sludge Dewatering ◽  
Sludge Cake ◽  
Solids Content

Dual polymer conditioning enhanced the dewatering characteristics of aerobically digested activated sludge from a pharmaceutical industry. The solids content of the dewatered sludge cake, from a belt filter, increased from 8-11% range to 11-14% range due to dual polymer conditioning. In addition, dual polymer conditioning improved the compressibility of the sludge cake, reduced blinding of the belt filter media, and enhanced solids capture by the belt filter. Initially, bench scale studies were conducted to screen suitable polymers for conditioning. From these studies, two polymers, namely, Calgon Catfloc 8964 (a low molecular weight, high cationic charge) and Calgon WT2476I (a high molecular weight, high cationic charge) were chosen for full scale experiments. This paper reports the details of the polymer screening methods, dual polymer conditioning procedures, and the results of the full scale trials.

A high-performance oil-free backing pump for electron microscopes

1978 ◽  
Vol 36 (1) ◽  
pp. 110-111
Author(s):  
G.K.W. Balkau ◽  
E. Bez ◽  
J.L. Farrant
Keyword(s):  
Molecular Weight ◽  
Electron Microscope ◽  
Hot Spots ◽  
High Performance ◽  
Carbonaceous Material ◽  
Contamination Rate ◽  
Low Molecular Weight ◽  
Principal Source ◽  
Rotary Pumps ◽  
Electron Microscopes

The earliest account of the contamination of electron microscope specimens by the deposition of carbonaceous material during electron irradiation was published in 1947 by Watson who was then working in Canada. It was soon established that this carbonaceous material is formed from organic vapours, and it is now recognized that the principal source is the oil-sealed rotary pumps which provide the backing vacuum. It has been shown that the organic vapours consist of low molecular weight fragments of oil molecules which have been degraded at hot spots produced by friction between the vanes and the surfaces on which they slide. As satisfactory oil-free pumps are unavailable, it is standard electron microscope practice to reduce the partial pressure of organic vapours in the microscope in the vicinity of the specimen by using liquid-nitrogen cooled anti-contamination devices. Traps of this type are sufficient to reduce the contamination rate to about 0.1 Å per min, which is tolerable for many investigations.

Low-molecular-weight heparin in the prevention and treatment of thromboembolic disorders

1998 ◽  
Vol 1 (5) ◽  
pp. 166-174 ◽  
Author(s):  
Evelyn R Hermes De Santis ◽  
Betsy S Laumeister ◽  
Vidhu Bansal ◽  
Vandana Kataria ◽  
Preeti Loomba ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight Heparin ◽  
Low Molecular Weight ◽  
Prevention And Treatment
Sign in / Sign up

Export Citation Format

Share Document