Microfluidic Membrane Filtration Systems to Study Biofouling

Abstract

In wastewater treatment, the membrane functions as a semipermeable barrier that restricts transport of undesired particulates. A major problem related to membrane filtration processes is fouling of membranes by colloidal particles, organic matter, and biomaterials. Among the various types of fouling, biofouling is one of the most severe, as it is a dynamic process. Even a few surviving cells that adhere to the membrane surface multiply exponentially at the expense of biodegradable substances in the feed solution. To analyze the mechanism of biofouling, membrane cell is typically considered as a black-box, where only the input and the output can be measured and put into use for analysis. Microfluidic devices are being used to study and understand the nature, properties, and evolution of biofouling. A primary advantage of a microfluidic membrane is the ability to conduct realtime observations of biofilm. This chapter presents an overview of the biofouling in membrane processes and different fabrication technique of microfluidic membrane systems.

Membrane Fouling Phenomena in Microfluidic Systems: From Technical Challenges to Scientific Opportunities

“…The most common removal procedures involve hydraulic and pneumatic cleaning [123]. Biofilm formation is affected by several biological factors, including cell physiology, mechanical properties and physicochemical factors, such as hydrodynamic conditions and membrane morphology [50,122]. These elements impact the film structure, leading to uncommon fouling phenomena such as the formation of filamentous structures, termed streamers, downstream of the membrane pores [124].…”

“…Membrane adsorption and pore blocking. In addition, streamer build-up was enhanced by smaller pores and lower flowrates; on the other side, crossflow filtration mode appeared to promote streamer formation, although at different magnitudes depending on the pore Biofilm formation is affected by several biological factors, including cell physiology, mechanical properties and physicochemical factors, such as hydrodynamic conditions and membrane morphology [50,122]. These elements impact the film structure, leading to uncommon fouling phenomena such as the formation of filamentous structures, termed streamers, downstream of the membrane pores [124].…”

“…Microorganism colonization of a surface is actually a complex process, in which various phenomena take place at different time and length scales; the interactions of bacteria, fungi or algae with the membrane causes the formation of a complex matrix, which hosts microorganisms and is made of nutrients and biological waste products, the extracellular polymeric substances (EPS), that are very prone to gelling [ 122 ]. This constitutes a major issue during cleaning procedures.…”

Microfluidic Chromatography for Enhanced Amino Acid Detection at Ocean Worlds

“…Microfluidic devices' lightweight construction and small form factor make them ideal modules for space applications as well (Hessel et al, 2020 ). Typically, electrical or chemical methods are utilized for microfluidic systems rather than size exclusion, due to the high pressures (>20 bar) needed for amino acid separation (Biswas et al, 2018 ). Previous research into microfluidic in situ spacecraft landers has focused on capillary electrophoresis and shown separation and detection of a variety of biologically relevant molecules including amino acids, aldehydes and ketones, carboxylic acids, and thiols (Skelley et al, 2005 , 2006; Chiesl et al, 2009 ; Benhabib et al, 2010 ; Stockton et al, 2010 , 2011; Mora et al, 2011 , 2013; Jensen et al, 2013 ; Kim et al, 2013 ; Creamer et al, 2017 ).…”