Estimating the removal efficiency of refractory dissolved organic matter in wastewater treatment plants using a fluorescence technique

Abstract

The spectroscopic characteristics and relative distribution of refractory dissolved organic matter (R-DOM) in sewage have been investigated using the influent and the effluent samples collected from 15 large-scale biological wastewater treatment plants (WWTPs). Correlation between the characteristics of the influent and the final removal efficiency was also examined. Enhancement of specific ultraviolet absorbance (SUVA) and a higher R-DOM distribution ratio were observed for the effluent DOM compared with the influent DOM. However, the use of conventional rather than advanced biological treatments did not appear to affect either the effluent DOM or the removal efficiency, and there was no statistical significant difference between the two. No consistent trend was observed in the changes in the synchronous fluorescence spectra of the DOM after biological treatment. Irrespective of the treatment option, the removal efficiency of DOM was greater when the influent DOM had a lower SUVA, reduced DOC-normalized humic substance-like fluorescence, and a lower R-DOM distribution. These results suggest that selected characteristics of the influent may provide an indication of DOM removal efficiency in WWTPs. For R-DOM removal efficiency, however, similar characteristics of the influent did not show a negative relationship, and even exhibited a slight positive correlation, suggesting that the presence of refractory organic carbon structures in the influent sewage may stimulate microbial activity and inhibit the production of R-DOM during biological treatment.

Combining chemical sequential extractions with 3D fluorescence spectroscopy to characterize sludge organic matter

“…Indeed, we showed that simple OM (protein-like fluorescence) was found in the most bioaccessible fractions (DOM and EPS) while the least bioaccessible ones (HLS and the non-extractable residue) contained significant amounts of complex and refractory OM (glycated protein-like, ligno-cellulosic-like and lipofuscin-like fluorescence). These results were consistent with those previously reported in the literature dealing with the evolution of fluorescence fingerprints in the water line of wastewater treatment: usually, fluorescence due to simple organic materials predominated in the raw sewage and drastically decreased in the effluent while the fluorescence due to complex organic materials persisted in the effluent or increased compared to the raw sewage (Hur et al, 2011). However, in the present work, protein-like fluorescence was systematically found in the fractions excepted in the non-extractable residue.…”

Estimating the Concentration and Biodegradability of Organic Matter in 22 Wastewater Treatment Plants Using Fluorescence Excitation Emission Matrices and Parallel Factor Analysis

“…The biodegradability of organic matter is an important factor for evaluating both the treatability of organic matter in wastewater treatment plants and biogeochemical roles of effluents in the receiving water [7,9]. It is also related to various features of organic matter, such as the molecular weight [40], the N:C ratio [41] and the fraction of protein-like materials [10,29,31].…”

“…Biodegradability is the most critical factor when evaluating the removal performances of many wastewater treatment plants primarily relying on biological processes [9]. The degree of biodegradability is also closely related to biogeochemical and ecological impacts of effluents on the receiving water [7,10].…”

Photodegradation and kinetics of edible oil refinery wastewater using titanium dioxide

“…Biodegradability determines the sustainability and suitability of wastewater for further treatment. 26 Dhanke and Wagh 27 reported that increasing the biodegradability index is good for biological degradation of wastewater. Nagar and Devra 28 stated that the use of advanced oxygen processes will increase the biodegradability of textile wastewater by using silver nanoparticles.…”