Evaluating the membrane fouling formation and chemical cleaning strategy in forward osmosis membrane filtration treating domestic sewage

Abstract

Free nitrous acid (FNA) shows strong potential as an effective cleaning reagent in fouling control in a forward osmosis filtration system, with a relatively longer time required.

Improving wastewater management using free nitrous acid (FNA)

“…and (iii) propensity of the fouling layer (Ab Hamid et al 2018, Filloux et al 2015. Filloux et al (2015) investigated the efficiency of FNA in treating fouled RO membranes, which suffered biofouling and scaling, from the full-scale water recycling and seawater desalination plants (Filloux et al 2015).…”

“…It is important to note that FNA can simultaneously achieve both biofouling removal and descaling in a one-step cleaning strategy (Filloux et al, 2015). In another study, FNA cleaning was applied to treat FO membranes that suffered biofouling, due to direct filtration in pre-concentrating raw wastewater (Ab Hamid et al 2018).…”

“…It was shown the 1-hour FNA exposure inactivated 43% of the biomass, which increased to 90% and 96%, respectively, when the treatment time was increased to 8 hours and after 24 hours (Ab Hamid et al 2018).…”

“…(1-hour cleaning for each cycle), whilst the water flux was recovered to >90% by other cleaning reagents (e.g. NaOCl, EDTA) (Ab Hamid et al 2018, Holloway et al 2007, Valladares Linares et al 2012. The formation of dense and compact fouling layer on the membrane can limit the FNA penetration into the fouling layer (Ab Hamid et al 2018, Filloux et al 2015, Mi and Elimelech 2010).…”

The Recent Progress in Modification of Polymeric Membranes Using Organic Macromolecules for Water Treatment

“…Membrane processes can be categorized based on various parameters such as the structure of the membrane, membrane material type, driving strength and separation mechanism, as well as the size range of extracted constituents. In general, the filtration membranes have been divided into four categories: microfiltration (MF), ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO) with reduced pore size in order to reject various size substances and effluences [46]. Among these pressure-driven membrane technologies, RO has gained great global interest and one of the promising large-scale processes due to the simplicity in plant design with low energy cost [47,48].…”