Overview on the hydrodynamic conditions found in industrial systems and its impact in (bio)fouling formation

Abstract

Biofouling is the unwanted accumulation of deposits on surfaces, composed by organic and inorganic particles and (micro)organisms. Its occurrence in industrial equipment is responsible for several drawbacks related to operation and maintenance costs, reduction of process safety and product quality, and putative outbreaks of pathogens. The understanding on the role of operating conditions in biofouling development highlights the hydrodynamic conditions as key parameter. In general, (bio)fouling occurs in a higher extension when laminar flow conditions are used. However, the characteristics and resilience of biofouling are highly dependent on the hydrodynamic conditions under which it is developed, with turbulent conditions being associated to recalcitrant biodeposits. In industrial settings like heat exchangers, fluid distribution networks and stirred tanks, hydrodynamics plays a dual function, affecting the process effectiveness while favouring biofouling formation. This review summarizes the hydrodynamics played in conventional industrial settings and provides an overview on the relevance of hydrodynamic conditions in biofouling development as well as in the effectiveness of industrial processes.

Stability of Ion Exchange Membranes in Electrodialysis

“…In turn, the hydrodynamics is determined by the shape of the channel and by the presence of spacer [ 82 ]. As expected, the enhancement of turbulence within the chambers of electrodialysis apparatuses helps washing out the deposits [ 83 , 84 ] and also removing the H + and OH − ions produced in catalytic generation reaction. Spacers of advanced geometry [ 85 ] or novel composition (e.g., ion-conductive spacers [ 86 ]) are used to promote the development of turbulence.…”

Biofilm formation under high shear stress increases resilience to chemical and mechanical challenges

“…Hydrodynamic conditions are mainly related to two phenomena in the biofilm development process: mass transport and mechanical stress. For instance, high fluid velocities are associated with increasing mass transport phenomena from the bulk to the surface (Fernandes et al 2021), and mechanical stress induces biofilm erosion and sloughing (Simões et al 2010). The consequences from the fluid movement to the biofilm colonizing cells are diverse, i.e.…”

Interactions between Penicillium brevicompactum/Penicillium expansum and Acinetobacter calcoaceticus isolated from drinking water in biofilm development and control

“…The study of inter-kingdom biofilms will substantially advance the current knowledge on biofilm development and behaviour under realism-based conditions. In this work, single species and inter-kingdom biofilm formation were characterized for two ff (Penicillium expansum and P. brevicompactum) and one bacterium (Acinetobacter calcoaceticus), isolated from the same DWDS (Gonçalves et al, 2006;Simões et al, 2007a), under two shear stress conditions commonly encountered in DWDS (Fernandes et al, 2021;Gomes et al, 2014). The ff were selected based on their prevalence (Gonçalves et al, 2006), while A. calcoaceticus was used as a model bacterium due to its increased relevance as an opportunistic microorganism and its association with infections related to hospital water supply (Gales et al, 2001;Gomes et al, 2016).…”