Influence of characterised natural organic material on activated carbon adsorption: I. Characterisation of concentrated reservoir water

Natural organic material (NOM) from Myponga Reservoir in South Australia was concentrated and fractionated using ultrafiltration into nominal molecular weight fractions < 500, 500–3000, 3000–10,000, 10,000–30,000 and > 30,000. The fractions were characterised using flow field-flow fractionation, 13C NMR, colour determination and potentiometric titration. The ultrafiltration fractions displayed a gradual transformation from highly coloured, highly branched, high carbohydrate structures to compounds with a prevalence of long chain aliphatic carbon with much lower carbohydrate content and colour. There were no clear trends in the carboxyl content of the fractions, as determined by both NMR and titration. Analysis of the titration data showed evidence of three distinct types of carboxyl groups and the same types of groups were present in each fraction.