Fate of natural organic matter (NOM) during ground water recharge using reclaimed water

Abstract

The scope of this study was to investigate how natural organic matter (NOM) from drinking water and soluble microbial products (SMP) generated in the wastewater treatment process influence the character of DOC in reclaimed water used for indirect potable reuse. Biodegradation studies in conjunction with XAD-fractionation and 13 C-NMR spectroscopy were applied to both characterize organic matter and to study removal mechanisms during subsequent soil-aquifer treatment (SAT). Based on hydraulically corresponding samples of drinking water and reclaimed water from reuse sites in Arizona and California, residual DOC in reclaimed water after SAT was dominated in concentration and character by NOM. Changes in DOC character were observed with increasing retention times during SAT in the direction to more aliphatic and less aromatic compounds indicative of humification with biodegradation as the dominant transformation process for bulk organics.