Effect of Mixed Liquor Volatile Suspended Solids on Membrane Fouling During Short and long-term Operation of Membrane Bioreactor

Abstract

The aim of this study was to examine the impact of different Mixed Liquor Volatile Suspended Solids (MLVSS) concentrations on membrane fouling, in a submerged Membrane Bioreactor (MBR) at short and long-term MBR operation for wastewater treatment. Three laboratory-scale in a submerged MBR system were operated under critical flux, sub-critical flux, and an intermittent suction time and backwashing conditions. At shortterm MBR operation with mixed liquors of 4,200 and 6,150 mg MLVSS L −1 , the hydraulic resistance of membranes followed a same trajectory with averages of 5.0E+12 m −1 , whereas for 7,940 mg MLVSS L −1 , a high resistance of up to 1.7E+13 m −1 was obtained. The result showed that high biomass concentrations decreased to permeability due to a bio-layer formed in the membrane surface and high Extracellular Polymeric Substance (EPS). ResumenEl objetivo del estudio fue examinar el impacto de diferentes concentraciones de sólidos suspendidos volátiles del licor mezclado en el ensuciamiento de las membranas en un bio-reactor con membranas sumergidas (BRMS) en periodos cortos y largos de operación durante el tratamiento del agua residual. Tres BRMS a escala laboratorio fueron operados bajo condiciones críticas, sub-críticas y condiciones de succión intermitente y retrolavados. En cortos tiempos de operación de los BRMS con concentraciones de licor mezclado de 4,200 y 6,150 mg SSVLM L −1 , la resistencia hidráulica de las membranas se comportó de manera similar con un promedio de 5.0E+12 m −1 , mientras para una concentración de 7,940 mg SSVLM L −1 , su obtuvo una alta resistencia con valores de 1.7E+13 m −1 . Los resultados mostraron que con concentraciones altas de biomasa la permeabilidad de las membranas disminuye debido a la formación de una biopelícula en la superficie de las membranas y a la presencia de Sustancia Poliméricas Extracelulares (SPE).Palabras clave: bio-reactor con membranas; ensuciamiento de las membranas; sólidos suspendidos volátiles; sustancias poliméricas extracelulares

Membrane fouling behavior and microbial community succession in a submerged membrane bioreactor treating harbor oily wastewater

“…It has been generally accepted that the membrane fouling is due to particle deposition on membrane surface and/or colloidal particle deposition inside membrane pores . These processes are mainly affected by membrane materials, feedwater characteristics, sludge characteristics, and operating conditions (Judd, 2004;Meng et al, 2009;Kim et al, 2010;Cosenza et al, 2013;Mannina and Cosenza, 2013;Estrada-Arriaga, et al, 2015). Among them, sludge characteristics are considered to be directly affected by the feedwater characteristics and operating conditions (i.e., aeration, hydraulic conditions, sludge retention time (SRT), hydraulic retention time (HRT), organic loading rate, and food microorganism ratio (F/M)).…”