AWWA WQTC69372

This powerpoint presentation begins by presenting the study focus on floc size that includes the following:granular filtration performance is afunction of the influent particle sizedistribution;potential to be used on-line - Dynamic Particle Analyzer (PDA) fromBrightwell Technologies, and - Photometric Dispersion Analyzer (PDA) fromRank Brothers; and,Drewes et al. have recently suggested thatthe average floc size (dn) was a usefulparameter when charge neutralizationcoagulation conditions prevailed. The Photometric Dispersion Analyzer and the Dynamic Particle Analyzer 2100 are presented as analytical tools. Study objective was to evaluate to what extent direct filtration performancecould be linked to the floc size or the flocculation index. Experimental desgin and set-up, and water characteristics are provided. Presentation conclusions indicated the following: the parameter, d_v, was the best indicator found todescribe flocculation from the particle counter PSD;this indicator was more sensitive and less variablethan the Flocculation Index provided by the PDA;establishing a direct link between d_v and filteredwater turbidity was not a simple task, although itwas observed that increasing d_v to values higherthan 25 um generally led to lower filtered waterturbidities;the addition of polymer significantly reduced theimportance of flocculation, although its impact wasminor on d_v; another characteristic than size wasmost likely impacted by the polymer; PASS100 in combination with polyDADMACwas selected as the best coagulationstrategy;this strategy was confirmed to be optimalusing an industrial pilot plant (50 m³/d); and,combining pre-ozonation and flocculationinto a single process is currently underinvestigation. Includes tables, figures.

Product Details

Edition:

Vol. - No.

Published:

11/01/2008

Number of Pages:

23

File Size:

1 file , 2.2 MB