Biofouling in reverse osmosis: phenomena, monitoring, controlling and remediation

Abstract

This paper is a comprehensive review of biofouling in reverse osmosis modules where we have discussed the mechanism of biofouling. Water crisis is an issue of pandemic concern because of the steady rise in demand of drinking water. Overcoming biofouling is vital since we need to optimize expenses and quality of potable water production. Various kinds of microorganisms responsible for biofouling have been identified to develop better understanding of their attacking behavior enabling us to encounter the problem. Both primitive and advanced detection techniques have been studied for the monitoring of biofilm development on reverse osmosis membranes. Biofouling has a negative impact on membrane life as well as permeate flux and quality. Thus, a mathematical model has been presented for the calculation of normalized permeate flux for evaluating the extent of biofouling. It is concluded that biofouling can be controlled by the application of several physical and chemical remediation techniques.

Marine Biofilms: A Successful Microbial Strategy With Economic Implications

“…One must bear in mind that small organisms are passively transported by sea currents and their chemotaxis toward a surface can only occur if the Fouling of ballast water with non-indigenous species 1.6-4% of annual operational cost for a ship Fernandes et al, 2016 Water desalination Biofouling of reverse osmosis membranes 5-20% of operational costs for cleaning; cost of biofouling ca. 30% of total operating costs Flemming, 1997;Maddah and Chogle, 2017 microorganism is close to the surface (Railkin, 2003). However, the low probability of the encounter between a given cell and a surface is counteracted by the number of microorganisms in natural seawater, estimated at 5 × 10 5 cells/mL in the continental shelf and upper 200 m of open ocean water (Whitman et al, 1998).…”

“…Improvements made in reverse osmosis membranes include the following: new interfacial polymerization monomers, usually with more functional or polar groups to increase hydrophilicity; better polymerization processes to increase hydrophilicity, reduce roughness and enhance antifouling by the addition of structures such as polymer brushes; surface modification through physical adsorption of e.g., surfactants or chemical treatment; and surface coating with compounds that act as a protective layer (Kang and Cao, 2012). When a biofilm is installed, membrane cleaning may represent 5-20% of operating costs and may be performed by chemical cleaning agents such as acids, metal chelating agents, and enzymes (Maddah and Chogle, 2017). Although pretreatment strategies may be efficient in removing nearly all bacterial cells, the few that survive may multiply on the membrane surface and cause biofouling.…”

Triple‐faced polypropylene: Fire retardant, thermally stable, and antioxidative

“…The demand for PP is estimated to reach ca. 62 million tons by 2020 [11]. Despite above-mentioned advantages and market necessities, PP suffers from a high fire risk because of its inherent flammable character.…”

Modeling and Designing of a Novel Lab-scale Passive Solar Still

“…However, only 1% is covered by accessible freshwater sources, which are limited to rivers, lakes and underground reservoirs [1][2]. The world's demand for drinking water has been increasing rapidly since the industrial revolution due to the continuous production of wastewater, which contaminates available freshwater sources [3][4][5]. Typically, membrane processes are utilized for the treatment of industrial wastewaters in micro and ultrafiltration processes, and for desalination of seawater by reverse osmosis to meet the increasing demand for freshwater [3,[6][7][8].…”