AWWA WQTC63990

The occurrence of pharmaceutically active compounds (PhACs) in drinking watersources worldwide raises health concerns and the removal of these compoundsby drinking water treatment processes is not well understood. The overallobjective of this study was to determine the effectiveness of ion exchange (IX)technology in removing trace anionic organic compounds in the presence ofcompeting anionic organic compounds, including natural organic matter (NOM),wastewater effluent organic matter (EfOM) and inorganic anions (e.g., sulfate,SO₄^2-), from wastewater impacted drinking water sources. Target compoundsselected for this work are the hydrophilic anionic PhACs ibuprofen (IBP) anddiclofenac (DCF). Both kinetics and equilibrium aspects are evaluated. Specificobjectives include the evaluation of:the impact of the background organic and inorganic matrix on ionexchange capacity in a batch reactor;kinetic limitations to maximum ion exchange capacity; and,single use and multiple reuse ion exchange resins efficiency.In this study, IBP removal rate at high initial concentration (C0 = 20 µg/L) was alittle greater than that at low initial concentration (C0 = 0.1 µg/L). The IBP removalkinetics were fast during the first cycle for both low and high initialconcentrations, but they became slower as the number of IX resin reuse cyclesincreased. In the case of IBP, the resin capacity was significantly reduced due torepeated use in the presence of 50 mg/L of sulfate, which resulted in 35 % and13 % IBP removal after 6 hr contact time in 1st and 2nd cycled IX resin reuse,respectively. However, in the case of DCF, sulfate effect was negligible so that85 % and 79 % DCF removals occurred after 6 hr contact time in 1st and 2ndcycled IX resin reuse, respectively. The IX resin capacity was reduced due torepeated use, which resulted in a decreased from 60 % to 30 % DCF removalafter 6 hr contact time going from 1st to 6th cycled IX resin reuse. Sulfate removalpercent was reduced from 97 % to 60 % after 3 hr contact time at 1st to 6th cycledIX resin reuse. The presence of NOM did not cause any significant difference inIBP removal percentage. A higher pH increased IBP removal rates by the IXresins. Includes table, figures.

Product Details

Edition:

Vol. - No.

Published:

11/01/2006

Number of Pages:

8

File Size:

1 file , 330 KB