No abstract

No abstract

aColumn Experiments: The Effect of pH a Technische Universität Dresden, Institut für Flow-through column experiments were carried out to investigate the influence of pH on Wasserchemie, 01062 the sorption of three phenols (2-methyl-4,6-dinitrophenol, 2,4,6-trichlorophenol, pentachloDresden, Germany rophenol) onto a natural sandy aquifer material collected from a bank filtration site of River Elbe, Germany. For the phenols investigated, an increase in sorption (retardation) with decreasing pH is observed indicating a stronger sorption of the neutral species in comparison to that of the anions formed by dissociation. The anions of 2-methyl-4,6-dinitrophenol and 2,4,6-trichlorophenol do not show significant sorption. On the contrary, pentachlorophenol showed sorption not only in neutral form but also in ionic form significantly which should be taken into account while assessing the fate and transport of such compound. A linear model based on the degree of protonation (calculated from pH and pK a ) can be used to resolve the apparent (observed) sorption coefficient (

No abstract

The removal of selected pharmaceuticals and personal care products, atrazine, and disinfection by-product precursors, was evaluated during a pilot-scale study conducted at the Bollman Water Treatment Plant in Concord, California, USA. Treatment alternatives included ozonation followed by biologically active filtration (BAF), and nanofiltration. Both technologies exhibited excellent broadspectrum removal of the spiked target contaminants. The ozone/BAF system in particular showed a high degree of effectiveness despite relatively low ozone doses corresponding to a low disinfection target (0.5-log Giardia reduction). The BAF system was observed to remove several contaminants that were relatively unreactive with ozone, demonstrating an important synergy between the ozone and BAF.