Effects of phosphate limitation in feed water on biofouling in forward osmosis (FO) process

A case study of fouling development and flux reversibility of treating actual lake water by forward osmosis process

“…DOC can be used as an indicator of the presence of microbial cells and related bioproducts which include EPS and soluble microbial products (SMPs) [38].…”

“…Feed water was filtered using type HA (0.45 μm) membrane filter (Millipore, Ireland) to remove suspended particles and macromolecules before use. To accelerate the fouling formation rate, the C:N:P mass ratio of feed water was adjusted to 100:20:10 (400 mg/L C, 80 mg/L N and 40 mg/L P) to provide a nutrient base for microorganism growth and avoid restricting the biofilm growth by lack of phosphorous [38,39]. The feed solution was 2 L of Mawson Lakes brackish water spiked with 1.8432 g sodium acetate (Faulding, Australia), 0.2072 g sodium dihydrogen phosphate (Chem Supply, Australia), 0.6492 g sodium nitrate (Chem Supply, Australia), and 20 g sodium chloride (Sigma puriss, MO, USA).…”

“…In the long-term biofouling study, interestingly, average daily flux was maintained at stable level (~5.5 L/m 2 ·h) with dechlorinated tap water as feed and 0.5 M NaCl as draw solution which indicates that the biofilm has reached a steady-state between growth and detachment throughout the experimental duration. More recently, phosphate limitation on microbial growth and biofilm formation was studied in a FO system treating wastewater [38]. They confirmed that limiting phosphate in the feed water is an effective way inhibiting the water flux decline and biofouling development.…”

Forward osmosis as a pre-treatment for treating coal seam gas associated water: Flux and fouling behaviour

“…Fluorescence signals detected in specific areas are known to be related to specific fractions of DOC. DOC can also be used as an indicator of the presence of microbial cells and related bioproducts which include extracellular polymeric substances (EPSs) and SMPs [12,22]. Although the DOC level in the CSG water feed solution was very low (1.8 mg/L), organic fouling was observed on both the TFC active and support layers.…”

Understanding, Monitoring, and Controlling Biofilm Growth in Drinking Water Distribution Systems

“…107-109 Biofilms have also been shown to elevate their EPS production in response to 320 phosphorus limitation, 110 which appears to serve as protective mechanisms against the growth 321 inhibiting effect of phosphorus limitation. 322…”