Activated sludge poly

Comeau et al. [46] have described a simple assay for separating and quantifying poly-beta-hydroxybutyrate and poly-beta-hydroxyvalerate in activated sludge samples involved sludge lyophilization, purification of the chloroform extract by re-extraction with water, and capillary gas liquid chromatography. The detection limit, estimated by using hydroxybutyric acid standards, was approximately lOug per litre. 

The problem here consists in listing the material parameters because, in activated sludge, they fluctuate strongly (much in contrast to ore flotation). Surely, the degree of hydrophobicity (wettability) of the particle surface (contact angle, ) will be of importance. Furthermore, the pH value, the concentration of the flocculant (poly-electrolyte), cF, the portion of solids, [Pg.30]

G. N. Rees, G. Vasiliadis, J. W. May and R. C. Bayly (1992). Differentiation of polyphosphate and poly-beta-hydroxybutyrate granules in an Acinetobacter sp. isolated from activated sludge. FEMS Microbiol. Lett., 73, 171-173. 

The ready availability of starch-based industrial wastes and their renewable nature merit their use as substrates for poly-betahydroxybutyrate (PHB) production from activated sludge. This would not only utilize the excess sludge generated and reduce the load on landfills, but would also contribute to reduction in the cost of PHB production by avoiding sterile conditions and pure carbon sources for maintenance and growth of pure cultures. PHB content is the most important factor affecting the production cost of PHB due to its effect on PHB yield and recovery efficiency, followed by cultural conditions and carbon substrates used (Khardenavis, 2007). 

Poly(vinyl alcohol) is the most readily biodegraded, compared to other vinyl polymers, e.g., polystyrene, polyethylene, and polypropylene. Respirometric assays with mixed culture activated sludge have shown that poly(vinyl alcohol) is mineralized [92]. Extensive studies have been reported on the purification, characterization, and mechanism on degradation of poly(vinyl alcohol) by enzymes isolated fi om pseudomonas. The polymer is degraded as the sole carbon source by thee organisms the mechanism of action is summarized in Figure 5.52. 

Casey, J. P. and Manly, D. G., 1976. Poly(vinyl alcohol) biodegradation by oxygen-activated sludge. Proceedings of 3rd International Biodegradation Symposium, Applied Science, Barkins, England. 

Imam, S.H. Gordon, S.H. Shogren,R.L. Greene,R.V. Biodegradationofstarch-poly((3-hydroxybutyrate-co-valerate) composites in municipal activated sludge. J. Environ. Polym. Degr. 1995, 3 (4), 205-213. 

Wallen, L.L. and Rohwedder, W.K. (1974) Poly-beta-hydroxytilkanoate from activated sludge. Emriron-... 

Pseudomonas fluorescens BM07 was isolated from activated sludge in a municipal wastewater treatment plant in Chinju, Korea, in 2001 (Lee et al. 2001). This strain was able to produce up to 25.2% (w/w) mcl-PHA that contained 30.8 mol% 3-hydroxy-cM-5-dodecenoate and 4.5 mol% 3-hydroxy-cw-7-tetradecenoate from nonrelated carbon sources such as fructose and succinate. Interestingly, stearic acid was taken up by this strain and stored inside the cell as the free acid. P fluorescens, especially strain GK13, is better known for its capability of degrading extracellular poly[(R)-3-hydroxyoctano-ate] (Schirmer and Jendrossek 1994 Schirmer et al. 1993,1995). 

Fig. 26 Biodegradation of PBSA copolymers in activated sludge a PBS, b Polyfbutylenes succinate-co-5 mol% butylene adipate) copolymer (PBSA-5), c Poly(butylenes succdnate-co-lO mol% butylene adipate) copolymer (PBSA-10), d PBSA-15, e PBSA-20 (Ding 2002)...

Fig. 27 Micrographs of poly(butylene succinate-co-butylene methylsuccinate) copolymers after biodegraded in activated sludge for 2 weeks a poly(butylene succinate-co-10 mol% butylene methylsuccinate), b poly(butylene succinate-co-20 mol% butylene methylsuccinate), c poly(butylene succinate-co-30 mol% butylene methylsuccinate), d poly(butylene succinate-co-40 mol% butylene methylsuccinate) (Sun 2005)...

Poly(carboxylic acid) Poly(acrylic acid salt)-co-(vinyl alcohol)-(M = 7300-12000). BOD measurements Optical density and analysis Activated sludge Pseudomonas sp. and Trichoderma sp. [106]... 

Bacterial Poly(3 hydroxybutyrate-co-3 Dynamic mechanical Activated sludge [115]... 

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