Assessment of photo-oxidative alterations to natural organic matter in water using fluorescence excitation emission matrices and liquid chromatography-organic carbon detection techniques

Abstract

Fluorescence excitation emission matrices (FEEMs) and liquid chromatography-organic carbon detection (LC-OCD) are relatively novel techniques currently used for analysing natural organic matter (NOM) in water.

Combining LC‐OCD analysis with design‐of‐experiments methods to optimize an advanced oxidation process for the treatment of industrial wastewater

“…In fact, this observation is supported by the other five LC‐OCD analyses for the centre point condition and the four axial point conditions in the DOE method; refer to Figure S‐2 in the Supplementary Material. A previous study reported a similar observation related to the treatment of surface water containing NOM and attributed it to the decomposition of particulate matter . For those conditions that achieved COD removals greater than 70 % (i.e.…”

“…For the wastewater 1 sample (shown in Figure a), the positions of the peaks were the same but the sizes of the peaks increased. Specifically, the size of peak 1 increased by approximately 40 %; it is hypothesized that this result is due to the transformation of particulate matter into dissolved DOC . For the wastewater 2 sample (shown in Figure b), the change in the chromatogram was much more drastic.…”

“…Specifically, the size of peak 1 increased by approximately 40 %; it is hypothesized that this result is due to the transformation of particulate matter into dissolved DOC. [22] For the wastewater 2 sample (shown in Figure 4b), the change in the chromatogram was much more drastic. Specifically, the pH-adjustment step transformed the one large peak at a retention time of 80 min into two peaks at lower retention times of approximately 51 min (denoted as 1) and 62 min (denoted as 2).…”

“…A previous study reported a similar observation related to the treatment of surface water containing NOM and attributed it to the decomposition of particulate matter. [22] For those conditions that achieved COD removals greater than 70 % (i.e. Figures 6d, 6f), it is hypothesized that a two-stage process occurred during the AO treatment as follows: first the particulate matter was decomposed (as mentioned above) and then that material was further broken down.…”

“…It has been applied to study NOM fractions in surface water, municipal wastewater, and sea water, and the efficacy of different NOM removal treatments . Additionally, it has been used to study the treatment of recalcitrant organic matter in paper mill effluent, and also the effect of photo‐oxidation on NOM in cooling water . These studies have demonstrated the valuable insight of LC‐OCD analysis towards an improved understanding of the complex relationship between sample composition and treatment efficacy that is not possible via conventional bulk measurements such as COD and TOC.…”