Different bacterial species and their extracellular polymeric substances (EPSs) significantly affected reverse osmosis (RO) membrane fouling potentials in wastewater reclamation

2018 ◽  
Vol 644 ◽  
pp. 486-493 ◽  
Author(s):  
Tong Yu ◽  
Hao Sun ◽  
Zhuo Chen ◽  
Yun-Hong Wang ◽  
Zheng-Yang Huo ◽  
...  
Keyword(s):  
Reverse Osmosis ◽  
Membrane Fouling ◽  
Extracellular Polymeric Substances ◽  
Bacterial Species ◽  
Wastewater Reclamation ◽  
Ro Membrane

scholarly journals A feasibility study on UV pretreatment for microfiltration and reverse osmosis membrane processes in wastewater reclamation

2013 ◽  
Vol 3 (3) ◽  
pp. 260-267
Author(s):  
Ho-Young Jeong ◽  
Yoon-Jin Kim ◽  
Ji-Hee Han ◽  
Dong-Ha Kim ◽  
Jinsik Sohn ◽  
...  
Keyword(s):  
Reverse Osmosis ◽  
Membrane Fouling ◽  
Treatment Options ◽  
Human Consumption ◽  
Feed Water ◽  
Reverse Osmosis Membrane ◽  
Wastewater Reclamation ◽  
Important Place ◽  
Quality Water ◽  
Small Footprint

Wastewater reclamation is where wastewater from various sources is purified so the water can be used by human consumption. Among many treatment options, membranes have gained an important place in wastewater reclamation. It allows the production of high quality water from wastewater, with a small footprint and affordable energy consumption. Nevertheless, membrane fouling is regarded as a serious problem due to the high fouling potential of wastewater. In this study, we applied ultraviolet (UV) processes as a pretreatment for membrane systems that are used for wastewater reclamation. Low pressure UV (LUV) and pulsed UV (PUV) were used to decompose or alter the organics in the feed water of the membranes. Effluent organic matter was characterized by total organic carbon (TOC) and UV absorbance (UVA). Also the effect of UV pretreatment on membrane fouling was investigated for microfiltration (MF) and reverse osmosis (RO) processes. The pretreatment of membranes using LUV or PUV was effective to control fouling of hollow fiber MF membranes. This is probably because of the reduction and modification of organics after UV treatments. However, the effect of UV pretreatment on RO flux was less significant, which is attributed to low fouling prophecy after MF treatment.

scholarly journals Direct Osmosis for Reverse Osmosis Fouling Control: Principles, Applications and Recent Developments

2009 ◽  
Vol 3 (1) ◽  
pp. 8-16 ◽  
Author(s):  
Jian-Jun Qin ◽  
Boris Liberman ◽  
Kiran A. Kekre ◽  
Ado Gossan
Keyword(s):  
Wastewater Treatment ◽  
Reverse Osmosis ◽  
Membrane Fouling ◽  
Chemical Potential ◽  
Water Desalination ◽  
Water And Wastewater Treatment ◽  
High Pressure Pump ◽  
Permeable Membrane ◽  
Fouling Control ◽  
Ro Membrane

Reverse osmosis (RO) has been widely applied in various water and wastewater treatment processes as a promising membrane technology. However, RO membrane fouling is a global issue, which limits it operating flux, decreases water production, increases power consumption and requires periodical membranes Cleaning-in-Place (CIP) procedure. This may result in low effectiveness, high cost and adds environmental issues related to the CIP solutions disposal. Forward osmosis (FO) or direct osmosis (DO) is the transport of water across a semi-permeable membrane from higher water chemical potential side to lower water chemical potential side, which phenomenon was observed in 1748. The engineered applications of FO/DO in membrane separation processes have been developed in food processing, wastewater treatment and seawater/brackish water desalination. In recent years, DO has been increasingly attractive for RO fouling control as it is highly efficient and environmentally friendly technique which is a new backwash technique via interval DO by intermittent injection of the high salinity solution without stoppage of high pressure pump or interruption of the operational process and allows keeping RO membrane continuously clean even in heavy bio-fouling conditions and operating RO membranes at high flux. This paper provides the state-of-the-art of the physical principles and applications of DO for RO fouling control as well as its strengths and limitations.

Determination and occurrence of organic micropollutants in reverse osmosis treatment for advanced water reuse

2012 ◽  
Vol 66 (1) ◽  
pp. 61-71 ◽  
Author(s):  
Veronica Gomez ◽  
Katariina Majamaa ◽  
Eva Pocurull ◽  
Francesc Borrull
Keyword(s):  
Wastewater Treatment ◽  
Reverse Osmosis ◽  
Water Reuse ◽  
Treatment Plant ◽  
Organic Micropollutants ◽  
Wastewater Reclamation ◽  
North East ◽  
Incomplete Removal ◽  
Wide Range ◽  
Ro Membrane

The growing demand on water resources has increased the interest in wastewater reclamation for multiple end-use applications such as indirect and direct potable reuse. In these applications, the removal of organic micropollutants is of a greater concern than in conventional wastewater treatment. This article presents a collection of data of trace organic micropollutants in an urban wastewater treatment plant (WWTP) in North East Spain using reverse osmosis (RO) membrane treatment. The RO rejection values of the organic molecules studied with a wide range of solute size and hydrophobicity were determined. Several chromatographic methods monitoring different endocrine disrupting chemicals (EDCs), pharmaceuticals and personal care products (PPCPs) were used. Results indicated that secondary effluents from this Spanish WWTP contained most of the studied organic compounds indicating incomplete removal of organics in the conventional treatment of the plant. However, the rejection of most micropollutants was high for all three RO membrane types (low energy, high rejection, fouling resistant) tested. It was observed that some selected micropollutants were less efficiently removed (e.g. the small and polar and the more hydrophobic) and the molecular weight and membrane material influenced removal efficiencies.

scholarly journals Physicochemical Properties of Extracellular Polymeric Substances Produced by Three Bacterial Isolates From Biofouled Reverse Osmosis Membranes

2021 ◽  
Vol 12 ◽  
Author(s):  
Zahid Ur Rehman ◽  
Johannes S. Vrouwenvelder ◽  
Pascal Saikaly
Keyword(s):  
Molecular Weight ◽  
Physicochemical Properties ◽  
Reverse Osmosis ◽  
Biofilm Formation ◽  
Extracellular Polymeric Substances ◽  
Nmr Analysis ◽  
Bacterial Strains ◽  
H Nmr ◽  
Ro Membrane ◽  
C Nmr

This work describes the chemical composition of extracellular polymeric substances (EPS) produced by three bacteria (RO1, RO2, and RO3) isolated from a biofouled reverse osmosis (RO) membrane. We isolated pure cultures of three bacterial strains from a 7-year-old biofouled RO module that was used in a full-scale seawater treatment plant. All the bacterial strains showed similar growth rates, biofilm formation, and produced similar quantities of proteins and polysaccharides. The gel permeation chromatography showed that the EPS produced by all the strains has a high molecular weight; however, the EPS produced by strains RO1 and RO3 showed the highest molecular weight. Fourier Transform Infrared Spectroscopy (FTIR), Proton Nuclear Magnetic Resonance (1H NMR), and Carbon NMR (13C NMR) were used for a detailed characterization of the EPS. These physicochemical analyses allowed us to identify features of EPS that are important for biofilm formation. FTIR analysis indicated the presence of α-1,4 glycosidic linkages (920 cm–1) and amide II (1,550 cm–1) in the EPS, the presence of which has been correlated with the fouling potential of bacteria. The presence of α-glycoside linkages was further confirmed by 13C NMR analysis. The 13C NMR analysis also showed that the EPS produced by these bacteria is chemically similar to foulants obtained from biofouled RO membranes in previous studies. Therefore, our results support the hypothesis that the majority of substances that cause fouling on RO membranes originate from bacteria. Investigation using 1H NMR showed that the EPS contained a high abundance of hydrophobic compounds, and these compounds can lead to flux decline in the membrane processes. Genome sequencing of the isolates showed that they represent novel species of bacteria belonging to the genus Bacillus. Examination of genomes showed that these bacteria carry carbohydrates-active enzymes that play a role in the production of polysaccharides. Further genomic studies allowed us to identify proteins involved in the biosynthesis of EPS and flagella involved in biofilm formation. These analyses provide a glimpse into the physicochemical properties of EPS found on the RO membrane. This knowledge can be useful in the rational design of biofilm control treatments for the RO membrane.

Performance Investigation of Pilot Study for Wastewater Reclamation Using Ferric Chloride as Coagulant

2013 ◽  
Vol 65 (4) ◽  
Author(s):  
Chin Boon Ong ◽  
Abdul Wahab Mohammad ◽  
Siti Rozaimah Sheikh Abdullah ◽  
Hassimi Abu Hasan
Keyword(s):  
Pilot Study ◽  
Ferric Chloride ◽  
Membrane Fouling ◽  
Treatment Plant ◽  
Effluent Treatment ◽  
System Stability ◽  
Wastewater Reclamation ◽  
Average Percentage ◽  
Pilot Unit ◽  
Ro Membrane

A pilot study was conducted to evaluate the efficiency of ferric chloride as coagulant agent on the long term performance to reverse osmosis membrane technology. The pilot unit comprised of 50m3/day pore controllable fiber (PCF) technology as a pre-treatment prior to RO for water reclamation from an effluent treatment plant based in Malaysia. The additions of ferric chloride ahead of PCF unit give high rejection of permeate quality after RO such as TSS, COD, alkalinity, and nitrite. However, there is deterioration of RO membrane performance after the pilot unit has been run continuously for 24 hours over 3 months. Average percentage reduction for parameters such as BOD5, COD, TDS, conductivity, and TSS for PCF-RO over 3 months operation is 51.12%, 70.01%, 68.36%, 68.39% and 69.17% respectively. Fouled RO membranes for both lines were analyzed using Fourier transform infrared (FTIR) spectroscopy and EDS coupled with scanning electron microscopy (SEM). EDS-SEM results showed that the foulants deposit on RO membrane for PCF-RO about 4.29-6.23µm and Fe element at 14.81% by the mean of weight. These imply that ferric chloride residual contribute to RO membrane fouling and thus affect the system stability and efficiency.

scholarly journals The Influence of Residual Coagulant Al on the Biofilm EPS and Membrane Fouling Potential in Wastewater Reclamation

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1056
Author(s):  
Shu Sun ◽  
Zhenhao Zhao ◽  
Xiaochun Cui ◽  
Mingxin Huo ◽  
Zhi Geng
Keyword(s):  
Membrane Fouling ◽  
Biofilm Formation ◽  
Extracellular Polymeric Substances ◽  
Significant Rise ◽  
Membrane Technology ◽  
Major Contributor ◽  
Wastewater Reclamation ◽  
Control Groups ◽  
Membrane Treatment ◽  
Residual Al

Biofouling is inevitable in wastewater reclamation when using membrane technology. In particular, the extracellular polymeric substances (EPS) from biofilm is a major contributor to biofouling. Coagulation is critical in the process of reusing wastewater before membrane treatment, and residual coagulants (e.g., Al salts) are able to alter the characteristics of the biofilm EPS. However, the distribution of residual Al across varying biofilm EPS fractions and its effect on the membrane fouling potential resulting from biofilm EPS remains unclear. We found that 34% of the residual Al was present in the soluble EPS (S-EPS), 26% in the loosely bound EPS (LB-EPS) and 40% in the tightly bound EPS (TB-EPS). Moreover, compared with the control groups, the residual Al in biofilm induced more biofilm formation and more EPS formation. Al reduced the zeta potential and increased the hydrophobicity of the EPS. These changes induced a significant rise in the membrane fouling potential of S-EPS and LB-EPS. This work provides coagulation support for wastewater reclamation using membrane technology.

Comparison of reverse osmosis membrane fouling characteristics in full-scale leachate treatment systems with chemical coagulation and microfiltration pre-treatments

2014 ◽  
Vol 71 (4) ◽  
pp. 580-587 ◽  
Author(s):  
Weerapong Rukapan ◽  
Benyapa Khananthai ◽  
Thirdpong Srisukphun ◽  
Wilai Chiemchaisri ◽  
Chart Chiemchaisri
Keyword(s):  
Reverse Osmosis ◽  
Membrane Fouling ◽  
Full Scale ◽  
Permeate Flux ◽  
Leachate Treatment ◽  
Chemical Coagulation ◽  
Cake Layer ◽  
Ro Membrane ◽  
Pre Treatment ◽  
Fouling Characteristics

Fouling characteristics of reverse osmosis (RO) membrane with chemical coagulation and microfiltration (MF) pre-treatment were investigated at full-scale leachate treatment systems. In chemical coagulation pre-treatment, solid separation from stabilized leachate was performed by ferric chloride coagulation followed by sand filtration. Meanwhile, MF pre-treatment and the RO system utilized direct filtration using a 0.03 µm membrane without chemical addition. MF pre-treatment yielded better pollutant removals in terms of organics and nitrogen. The study on effect of pre-treatment on RO membrane fouling revealed that accumulated foulant on the RO membrane in MF pre-treatment was significantly lower than that of chemical coagulation. Nevertheless, NaOH cleaning of the fouled RO membrane after chemical coagulation pre-treatment could better recover its permeate flux, thus suggesting that the formation of a loose-structure cake layer by chemical coagulation pre-treatment could allow effective penetration of chemical cleaning and detachment of foulant layer from the membrane surface.

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