Fluorescence characterization of organic matter and fouling: Case study in a full‐scale reverse osmosis membrane treatment plant

Abstract

Membranes used for water treatment are subject to organic fouling, caused by organic matter in source water. Characterizing organic matter has the potential to improve fouling prediction since the development of an organic fouling layer on the membrane is dependent on the specific characteristics of the organic matter. A field study was performed at a full-scale reverse osmosis water treatment plant that treats secondary wastewater effluent for industrial reuse at a power plant. Samples were collected at various points within the treatment process and were analyzed for turbidity, total organic carbon (TOC), conductivity, and fluorescence Excitation Emission Matrices (EEM). Parallel factor analysis (PARAFAC) was used to generate representative fluorescence measurements of the organic matter. Results indicate that TOC and fluorescence measurements were effective in differentiating between two observed fouling periods at multiple locations within the treatment plant. However, none of the water quality measurements were effective in tracking treatability of organic matter throughout pretreatment. The results of this case study provide important information about the relationship between fluorescence NOM signals and membrane fouling that can be used in future online detection systems. • Practitioner points• TOC and fluorescence measurements were effective in differentiating between the high fouling and low fouling periods. • Water quality measurements were not effective in tracking changes in organic matter throughout pretreatment. • Implementation of online fluorescence monitoring of fouling potential could be used for real-time process control.

Screening the Performance of a Reverse Osmosis Pilot-Scale Process that Treats a Blended Feedwater Containing Nanofiltration Concentrate and Brackish Groundwater

“…Feedwater containing TOC at a concentration less than 0.5 mg/L is unlikely to cause organic fouling whereas it is likely to occur if the value is greater than 2 mg/L [12,19]. Moreover, excitation emission matrix (EEM) can be used to track organic matter changes, particularly for humic and fulvic acids, aromatic proteins, and soluble microbials; fluorescence regional integration (FRI) divides excitation and emission ranges into sections that characterize the organics present in the sample [20,21].…”