Journal of Membrane Science & Technology

3DEEM fluorescence spectroscopy for on-line membrane bioreactor fouling control

2^nd International Conference on Membrane Science and Technology

September 13-14, 2018 | London, UK

Geoffroy Lesage, C Jacquin and M Heran

Universite de Montpellier, France

Scientific Tracks Abstracts: J Membr Sci Technol

Abstract:

Introduction: A major limitation for the widespread application of membrane bioreactors (MBR) is membrane fouling. Strategies have already been established to control reversible fouling caused by particles and flocs deposited onto the membrane surface (e.g. relaxation, backwash, air scouring). However, those strategies are not fully efficient for molecules that can adsorb onto the membrane surface and inside the pores, causing irreversible fouling. The understanding and control of irreversible fouling is essential for the long-term and sustainable operation of MBR. Molecules which promote irreversible fouling are mostly organic, colloidal or soluble compounds, present in the liquid phase, also referred to as bulk supernatant or effluent organic matter (EfOM). Many research groups agree that soluble microbial products (SMP) are one of the main MBR foulants and the major source of dissolved organic carbon in MBR bulk and permeate. But, due to EfOM complexity, this statement is still controversial and the exact composition of the EfOM responsible for membrane fouling remains relatively unclear. Thus, in order to increase knowledge about EfOM in MBR bulk, efficient and easy-to-use characterization tools that could be used on- line have to be developed. Such advanced tools will contribute to a better understanding of the origin of foulants in MBR, the contribution of SMP in EfOM, or even the ambivalent role of natural organic matter (NOM) in MBR processes in general. Material & Methods: The chosen reference MBR (named as MBR1), was included in the treatment line of a wastewater treatment plant (WWTP) from the Montpellier area, France (60.000 p.e). A three-dimensional excitation and emission matrix fluorescence (3DEEM) was evaluated for direct quantification of EfOM fractions in full-scale MBR bulk supernatant and permeates samples. 3DEEM data were analyzed using the volume of fluorescence (?) parameter from the fluorescence regional integration (FRI) method. Principal component analysis (PCA) was used to investigate possible correlations between conventional Lowry and Dubois methods, liquid chromatography coupled to organic carbon and organic nitrogen detection (LC-OCD-OND) and 3DEEM. Results & Discussion: Two mathematical correlations were established between LC-OCD-OND and 3DEEM data to quantify protein-like and humic-like substances. These correlations were validated with supplementary data from the initial full-scale MBR, and were checked with samples from other systems. Humic-like correlation showed satisfactory prediction for a second full-scale MBR and a CAS system. Conclusions: Within this study, an original method based on 3DEEM integration through the volume of fluorescence (?) was proposed to investigate dissolved organic matter in WWT systems. This rapid determination could be very useful for monitoring online MBR processes. The average difference of membrane rejection efficiencies calculated with LC-OCD-OND and 3DEEM is around 7% and 4% for protein- and humic-like substances, respectively. Hence, 3DEEM is a quick and accurate method to study fouling behavior of EfOM. This can potentially be used for on-line applications and is a promising method for real-time control of MBRs and WWTs. Recent Publications 1. Yu H, Qu F, Sun L, Liang H, Han Z, et al. (2015) Relationship between soluble microbial products (SMP) and effluent organic matter (EfOM): characterized by fluorescence excitation emission matrix coupled with parallel factor analysis. Chemosphere 121:101???109. 2. Myat D T, Mergen M, Zhao O, Stewart M B, Orbell J D, et al. (2014) Membrane fouling mechanism transition in relation to feed water composition. J. Membr. Sci. 471:265???273.

Biography :

Geoffroy Lesage graduated from Toulouse University in 2006 (M.S. of Environmental Process Engineering) and received his PhD from the National Institute of Applied Science of Toulouse (2009), where under the direction of Pr. Mathieu Sperandio and Pr. Ligia Tiruta-Barna he studied an hybrid wastewater treatment process associating adsorption onto activated carbon and biodegradation for hazardous micropollutants removal (LISBP, Toulouse University, France). In 2012, Geoffroy became Associate Professor at the European Membrane Institute (IMemEau group, Membrane Engineering Department) at Montpellier University where he develops synergistic membrane and biodegradation strategies for wastewater streams. Specific research areas include wastewater treatment, adsorption, biological process modelling, membrane biological reactors, dissolved organic matter characterization and micropollutants issues (chemical analysis and toxicity assessments). He has published 26 articles in international journal (citations: 204, h index: 9, i10: 8), 2 book chapters and has presented his works in 64 national and international conferences and workshops (included 7 invited lectures). He has supervised or co-supervised 16 M.S. students, 10 Ph.D. and 6 Post-doc in the field of wastewater treatment and environmental engineering.

E-mail: geoffroy.lesage@umontoellier.fr