Particle Size Distribution (PSD) Obtained in Effluents from an Advanced Primary Treatment Process Using Different Coagulants

Mejía, Alma Chávez; Cisneros, Blanca Jiménez

doi:10.1007/978-3-642-59791-6_24

Cited by 15 publications

(5 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…After rapid mix at 400 rpm (mean shear rate, G = 518 s −1 ) for 5–60 s, slow stirring at 50 rpm ( G = 23 s −1 ) for 10–30 min and settling for 30 min, supernatant samples were withdrawn for turbidity measurements. The G values were calculated following the method of Mejia and Cisneros,15 who used a similar jar test device.…”

Section: Methodsmentioning

confidence: 99%

The effect of rapid mixing on the break‐up and re‐formation of flocs

Yükselen

Gregory

2004

J of Chemical Tech & Biotech

118

View full text Add to dashboard Cite

The effect of rapid mixing on floc formation, breakage and re-formation using aluminium sulfate ('alum'), polyaluminium chloride and a cationic polyelectrolyte were investigated using a continuous optical monitoring technique. For the aluminium-based coagulants it was found that, with shorter times of rapid mix, larger flocs were formed, but only limited re-growth occurred in all cases, indicating a significant irreversibility of the floc break-up process. For cationic polyelectrolytes, the re-growth of flocs occurred to a much greater extent and with longer rapid mix times floc breakage was almost fully reversible. Residual turbidity values before floc breakage and after re-formation were consistent with the dynamic monitoring results.

show abstract

Section: Methodsmentioning

confidence: 99%

The effect of rapid mixing on the break‐up and re‐formation of flocs

Yükselen

Gregory

2004

J of Chemical Tech & Biotech

118

View full text Add to dashboard Cite

show abstract

“…The structure of activated sludge model did not discourage research on the use of particle size information for a better understanding of biological processes . A procedure for particle size distribution (PSD) analysis was developed, involving a sequence of different sizes in the filtration and ultra‐filtration ranges from 1600 nm (1.6 µm) down to 2 nm; this analysis enabled a specific fingerprint of the selected wastewater for different COD fractions to be obtained as well as other parameters such as total organic carbon (TOC), colour, etc .…”

Section: Milestones For Future Progressmentioning

confidence: 99%

Evolution of the activated sludge process: the first 50 years

Orhon

2014

J of Chemical Tech & Biotech

View full text Add to dashboard Cite

The paper presents a critical overview of the first 50 years in the evolution of the activated sludge process. Recognition of the role of aeration and microbial activity in the purification of sewage in the early studies established the basis for the accidental discovery of the process, which was immediately adapted into practice. The problems encountered during operation started a period of empirical expansion with many process modifications. As scientific support lagged behind practice, efforts were then directed towards exploring and understanding the fundamentals of the system related to substrate removal mechanisms, microbiology, process kinetics and stoichiometry, nitrogen transformations and, then, translating accumulated information into design. Extensive research generated remarkable findings which should be regarded as major milestones for future progress in many areas such as fractionation of substrate and biomass, particle size distribution, and substrate storage. A rational foundation of the activated sludge process for the removal of organic carbon could then be established based on mass balance. This approach also defined essential parameters that could relate microbial reactions involved with plant design and operation. Scientific ideas and discoveries have also enabled conceptual development of many emerging technologies such as the sequencing batch reactor, enhanced biological phosphorus removal, the oxic-settling anaerobic process, and the super-fast membrane bioreactor.

show abstract

“…In order to compare flocculation performances and particle removal efficiencies of the EPS samples, experiments were conducted with three high molecular weight polyacrylamide based commercial polyelectrolytes; Magnafloc LT 22 (medium/low cationic), Magnafloc LT 20 (nonionic), and Magnafloc LT 25 (low anionic) (Ciba Specialty Chemicals, now BASF). The G values above represent average shear rates in the stirred suspensions and were calculated following Mejia and Cisneros (2000), who used a similar jar test device.…”

Section: Experimental Procedures Of Flocculationmentioning

confidence: 99%