The primary objective of this research was to understand the impact of chemical sequencing and coagulation pH/zeta potential on filtration performance. The secondary goal was to determine effective coagulation processes in terms of pH, zeta potential, and coagulant dose for treating challenging (i.e., runoff-type) raw waters. The following are highlights from this project: Use of high coagulation pH (approximately 7.5) provided more consistent filtration performance over a wider range of coagulation conditions than lower pH levels. Because higher pH significantly increases the optimum zeta potential range for filtration, a practical implication of this result is that use of a high coagulation pH process may be the most effective short-term treatment strategy for rapidly changing, runoff-type waters containing low alkalinity and high NOM levels. The photometric dispersion analyzer (PDA) appears to be a useful alternative to jar tests for determining optimum coagulant doses and quickly evaluating different coagulation scenarios.A schematic diagram of the PDA system used in this study is provided in Figure 3.1. ... Addition/ pH adjustment 2-L beaker Power supply (5V DC) ^ Waste A/D board/ Lab view Software Data acquisition Figure 3.1 Schematic diagram ofanbsp;...
|Title||:||The Impact Of Chemical Sequencing On Filtration Performance|
|Author||:||D. Gregory, W. Bellamy|
|Publisher||:||IWA Publishing - 2004-01-01|