scholarly journals Pilot-Scale Investigation of Forward/Reverse Osmosis Hybrid System for Seawater Desalination Using Impaired Water from Steel Industry

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Hanaa M. Ali ◽  
Hanaa Gadallah ◽  
Sahar S. Ali ◽  
Rania Sabry ◽  
A. G. Gadallah
Keyword(s):  
Reverse Osmosis ◽  
Hybrid System ◽  
Membrane Fouling ◽  
Steel Industry ◽  
Water Flux ◽  
Operating Time ◽  
Pilot Scale ◽  
Operating Conditions ◽  
Hybrid Process ◽  
Impaired Water

This paper was focused on the investigation of a forward osmosis- (FO-) reverse osmosis (RO) hybrid process to cotreat seawater and impaired water from steel industry. By using this hybrid process, seawater can be diluted before desalination, hence reducing the energy cost of desalination, and simultaneously contaminants present in the impaired water are prevented from migrating into the product water through the FO and RO membranes. The main objective of this work was to investigate on pilot-scale system the performance of the combined FO pretreatment and RO desalination hybrid system and specifically its effects on membrane fouling and overall solute rejection. Firstly, optimization of the pilot-scale FO process to obtain the most suitable and stable operating conditions for practical application was investigated. Secondly, pilot-scale RO process performance as a posttreatment to FO process was evaluated in terms of water flux and rejection. The results indicated that the salinity of seawater reduced from 35000 to 13000 mg/L after 3 hrs using FO system, while after 6 hrs it approached 10000 mg/L. Finally, FO/RO system was tested on continuous operation for 15 hrs and it was demonstrated that no pollutant was detected neither in draw solution nor in RO permeate after the end of operating time.

Nanofiltration of colored surface water: Quebec's experience

2003 ◽  
Vol 3 (5-6) ◽  
pp. 15-22
Author(s):  
P. Kouadio ◽  
M. Tétrault
Keyword(s):  
Drinking Water ◽  
Surface Water ◽  
Membrane Fouling ◽  
Pilot Scale ◽  
Operating Conditions ◽  
Quebec City ◽  
Water Regulation ◽  
Eastern Canada

Three colored surface water nanofiltration pilot-scale projects were conducted in the province of Quebec (eastern Canada), between November 2000 and March 2002, by the company H2O Innovation (2000) inc., for the municipalities of Lac Bouchette, Latulipe-et-Gaboury and Charlesbourg (now part of Quebec City). Results indicated that nanofiltration permeate quality has an advance on present drinking water regulation standard in Quebec, but important membrane fouling occurred. Fouling can be controlled by pretreatment and optimization of the operating conditions.

scholarly journals Application of forward osmosis in reusing the brackish concentrate produced in reverse osmosis plants with secondary treated wastewater as feed solution: a case study

2016 ◽  
Vol 6 (4) ◽  
pp. 533-543 ◽  
Author(s):  
W. D. Wang ◽  
M. Esparra ◽  
H. Liu ◽  
Y. F. Xie
Keyword(s):  
Reverse Osmosis ◽  
Membrane Fouling ◽  
Water Flux ◽  
Forward Osmosis ◽  
Pump Energy ◽  
Feed Solution ◽  
Disinfection Byproducts ◽  
Treated Wastewater ◽  
Membrane Flux ◽  
Flux Decline

This study evaluated the feasibility of forward osmosis (FO) in diluting and reusing the concentrate produced in a reverse osmosis (RO) plant in James City County, VA. Secondary treated wastewater (STW) was used as the feed solution. Findings indicated that pH had slight effects on the water flux of the FO membrane. As the concentration of total dissolved solids (TDS) in the concentrate was diluted from 12.5 to 1.0 g/L or the temperature in the STW decreased from 23 to 10 °C, the membrane flux decreased from 2.2 to 0.59 and 0.81 L/(m2 h), respectively. The FO membrane showed a good performance in the rejection of organic pollutants, with only a small part of the protein-like substances and disinfection byproducts permeating to the diluted concentrate. During an 89-hour continuous operation, water flux decline due to membrane fouling was not observed. Controlling the TDS in the second-stage FO effluent at 1.5 g/L, approximately 8.3% of the pump energy input could be saved. The consumption of groundwater was reduced from 22.7 × 103 to 10.6 × 103 m3/d. FO was proved to be an effective method in both diluting the discharged concentrate and reducing the energy consumption of RO.

Treatment of highly-colored surface water by a hybrid microfiltration membrane system incorporating ion-exchange

2018 ◽  
Vol 19 (3) ◽  
pp. 855-863 ◽  
Author(s):  
T. Miyoshi ◽  
Y. Takahashi ◽  
T. Suzuki ◽  
R. Nitisoravut ◽  
C. Polprasert
Keyword(s):  
Surface Water ◽  
Hybrid System ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Membrane System ◽  
Pilot Scale ◽  
Manganese Concentration ◽  
Moderate Increase ◽  
Coagulant Dosage ◽  
Filtration System

Abstract This study investigated the performance of a hybrid membrane filtration system to produce industrial water from highly-colored surface water. The system consists of a membrane filtration process with appropriate pretreatments, including coagulation, pre-chlorination, and anion exchange (IE) process. The results of the pilot-scale experiments revealed that the hybrid system can produce treated water with color of around 5 Pt-Co, dissolved manganese concentration of no more than 0.05 mg/L, and a silt density index (SDI) of no more than 5 when sufficient coagulant and sodium hypochlorite were dosed. Although the IE process effectively reduced the color of the water, a moderate increase in the color of the IE effluent was observed when there was a significant increase in the color of the raw water. This resulted in a severe membrane fouling, which was likely to be attributed to the excess production of inorganic sludge associated with the increased coagulant dosage required to achieve sufficient reduction of color. Such severe membrane fouling can be controlled by optimising the backwashing and relaxation frequencies during the membrane filtration. These results indicate that the hybrid system proposed is a suitable technology for treating highly-colored surface water.

Reverse Osmosis Technology for Wastewater Reuse

1991 ◽  
Vol 24 (9) ◽  
pp. 215-227 ◽  
Author(s):  
B. J. Mariñas
Keyword(s):  
Water Quality ◽  
Reverse Osmosis ◽  
Membrane Fouling ◽  
Quality Parameters ◽  
Operating Conditions ◽  
Water Quality Parameters ◽  
Feed Water ◽  
Hydraulic Pressure ◽  
Predominant Component ◽  
Percent Removal

Reverse osmosis technology has a great potential in the field of wastewater reclamation. A reverse osmosis plant includes the following processes: (1) feed water microfiltration and chemical conditioning, (2) membrane treatment, (3) permeate aeration, neutralization and disinfection, and (4) concentrate (liquid residue) treatment and disposal. The performance of reverse osmosis membranes depends on operating conditions and water quality parameters. Permeate productivity and contaminant removals increase with applied hydraulic pressure. Water quality parameters such as concentration, composition and pH also affect contaminant removal efficiencies. For example, the treatment of a simulated wastewater containing 10 mg/L of nitrate with a commercial polyamide-type reverse osmosis membrane resulted in membrane permeates containing approximately 0.05 mg/L of nitrate (or 99.5 percent removal) when sodium chloride was the major dissolved solid present in the feed water, and 1 mg/L (or 90 percent removal) when sodium sulfate was the predominant component. The removals of weak electrolyte contaminants are affected by feed water pH. For example, the removal of boron by a cellulose acetate-type membrane was reported to be greater than 99 percent at a pH of approximately 11, and less than 30 percent at a pH of 7. The practice of pre-treatment processes such as microfiltration and chemical conditioning can minimize performance deterioration resulting from membrane fouling by inorganic precipitates, organic macromolecules and microorganisms (biofouling).

Application of forward osmosis (FO) under ultrasonication on sludge thickening of waste activated sludge

2015 ◽  
Vol 72 (8) ◽  
pp. 1301-1307 ◽  
Author(s):  
Nguyen Cong Nguyen ◽  
Hau Thi Nguyen ◽  
Shiao-Shing Chen ◽  
Nhat Thien Nguyen ◽  
Chi-Wang Li
Keyword(s):  
Activated Sludge ◽  
Hybrid System ◽  
Membrane Fouling ◽  
Water Flux ◽  
Forward Osmosis ◽  
Bound Water ◽  
Feed Solution ◽  
N Removal ◽  
Sludge Thickening ◽  
Sludge Concentration

Forward osmosis (FO) is an emerging process for dewatering solid–liquid stream which has the potential to be innovative and sustainable. However, the applications have still been hindered by low water flux and membrane fouling when activated sludge is used as the feed solution due to bound water from microbial cells. Hence, a novel strategy was designed to increase sludge thickening and reduce membrane fouling in the FO process under ultrasonic condition. The results from the ultrasound/FO hybrid system showed that the sludge concentration reached up to 20,400 and 28,400 mg/L from initial sludge concentrations of 3000 and 8000 mg/L with frequency of 40 kHz after 22 hours, while the system without ultrasound had to spend 26 hours to achieve the same sludge concentration. This identifies that the presence of ultrasound strongly affected sludge structure as well as sludge thickening of the FO process. Furthermore, the ultrasound/FO hybrid system could achieve NH4+-N removal efficiency of 96%, PO43−-P of 98% and dissolved organic carbon (DOC) of 99%. The overall performance demonstrates that the proposed ultrasound/FO system using seawater as a draw solution is promising for sludge thickening application.

scholarly journals Flux Optimization in Reverse Osmosis via the Solution-Diffusion Model

2019 ◽  
Vol 4 (5) ◽  
pp. 39-44
Author(s):  
Hisham A. Maddah
Keyword(s):  
Osmotic Pressure ◽  
Reverse Osmosis ◽  
Diffusion Model ◽  
Water Flux ◽  
Applied Pressure ◽  
Arabian Gulf ◽  
Water Sources ◽  
Operating Conditions ◽  
Membrane Thickness ◽  
Membrane Type

This paper suggests a new method of predicting flux values at reverse osmosis (RO) desalination plants.  The study is initiated by using the solution-diffusion model that is applied to the groundwater source at Abqaiq plant (500 RO plant) at Saudi Aramco, Dhahran, Saudi Arabia in order to calculate the osmotic pressure of the treated water for Shedgum/Abqaiq groundwater. For modelling purposes, the same technique is used to determine the osmotic pressure drops at the same plant configuration and operating conditions when using seawater sources such that of Arabian Gulf and the Red Sea waters. High rejection brackish water RO (BWRO) element Toray TM720D-400 with 8" is the RO membrane type that is used at Abqaiq plant. The calculated osmotic pressures of the three water sources, assuming that they are all treated at Abqaiq plant, are utilized to determine the appropriate flux values as well as membrane resistances of different BWRO Toray membranes. Values of numerous parameters such as water permeability constant, applied pressure, gas constant, water temperature, water molar volume and membrane thickness, water salinity/TDS are taken into account to develop our calculations through the solution-diffusion model. A comparison between low-pressure, standard and high-pressure BWRO Toray membranes performance have been established to select the ideal membrane type for the treatment of water from various sources at Abqaiq plant. The model results confirm an inverse relationship between the membrane thickness and the water flux rate. Also, a proportional linear relation between the overall water flux and the applied pressure across the membrane is identified. Higher flux rates and lower salinity indicate lower membrane resistance which yields to the higher water production. Modelled data predict that BWRO Toray TM720D-440 with 8" membrane is the optimal BWRO membrane choice for the three water sources at Abqaiq plant.

scholarly journals Effect of Initial Water Flux on the Performance of Anaerobic Membrane Bioreactor: Constant Flux Mode versus Varying Flux Mode

Membranes ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 203
Author(s):  
Xiawen Yi ◽  
Meng Zhang ◽  
Weilong Song ◽  
Xinhua Wang
Keyword(s):  
Membrane Fouling ◽  
Membrane Surface ◽  
Water Flux ◽  
Operating Time ◽  
Operating Mode ◽  
Initial Water ◽  
Constant Flux ◽  
Membrane Performance ◽  
Fouling Mitigation ◽  
Flux Mode

Anaerobic membrane bioreactors (AnMBRs) have aroused growing interest in wastewater treatment and energy recovery. However, serious membrane fouling remains a critical hindrance to AnMBRs. Here, a novel membrane fouling mitigation via optimizing initial water flux is proposed, and its feasibility was evaluated by comparing the membrane performance in AnMBRs between constant flux and varying flux modes. Results indicated that, compared with the constant flux mode, varying flux mode significantly prolonged the membrane operating time by mitigating membrane fouling. Through the analyses of fouled membranes under two operating modes, the mechanism of membrane fouling mitigation was revealed as follows: A low water flux was applied in stage 1 which slowed down the interaction between foulants and membrane surface, especially reduced the deposition of proteins on the membrane surface and formed a thin and loose fouling layer. Correspondingly, the interaction between foulants was weakened in the following stage 2 with a high water flux and, subsequently, the foulants absorbed on the membrane surface was further reduced. In addition, flux operating mode had no impact on the contaminant removal in an AnMBR. This study provides a new way of improving membrane performance in AnMBRs via a varying flux operating mode.

scholarly journals Assessing Reverse Osmosis for Water Recycling in Alcoholic Fermentation Processes

2009 ◽  
Vol 7 (1) ◽  
Author(s):  
Marjorie Gavach ◽  
Camille Sagne ◽  
Claire Fargues ◽  
Marielle Bouix ◽  
Martine Decloux ◽  
...  
Keyword(s):  
Reverse Osmosis ◽  
Alcoholic Fermentation ◽  
Tap Water ◽  
Pilot Scale ◽  
Reduction Factor ◽  
Operating Conditions ◽  
Transmembrane Pressure ◽  
Inhibitory Compounds ◽  
Fermentation Stage ◽  
Rejection Rates

Recycling the stillage condensates to dilute worts in the fermentation stage would be an effective way to decrease wastewater production and ground water consumption. However, condensates contain fermentation inhibiting solutes, such as volatile acids, alcohols and aromatic compounds that should be removed. Reverse osmosis was investigated as a clean process for such a purpose. Pilot scale experiments were carried out with industrial condensates and using Hydranautics ESPA2 membrane. The influence of transmembrane pressure (TMP), volume reduction factor (VRF) and pH on permeate flow rate and rejection rates of inhibitory compounds were investigated. The optimal operating conditions were TMP=10 bar to get the maximal admissible permeate flow, a low VRF to produce the less concentrated permeate and a pH ? 6 to obtain the highest rejection rates of the acids. Results were confirmed by trials at pre-industrial scale in a distillery. However, the permeate produced at pH 6 proved to be less fermentable than the permeate produced at natural pH because of an increase in the osmotic pressure. Natural pH permeate displayed a fermentation activity almost equivalent to tap water chosen as the blank. The remaining inhibitory acids did not seem to significantly hinder yeast growth nor yeast physiology.

scholarly journals Aggravated biofouling caused by chlorine disinfection in a pilot-scale reverse osmosis treatment system of municipal wastewater

2021 ◽  
Author(s):  
Li-Wei Luo ◽  
Yin-Hu Wu ◽  
Yun-Hong Wang ◽  
Xin Tong ◽  
Yuan Bai ◽  
...  
Keyword(s):  
Reverse Osmosis ◽  
Relative Abundance ◽  
Membrane Fouling ◽  
Municipal Wastewater ◽  
Water Pressure ◽  
Pilot Scale ◽  
Resistant Bacteria ◽  
Feed Water ◽  
Chlorine Disinfection ◽  
Key Species

Abstract The reverse osmosis (RO) system is widely applied to produce reclaimed water for high-standard industrial use. Chlorine disinfection is the main biofouling control method in the RO systems for wastewater reclamation. However, researchers reported the adverse effects of chlorine disinfection which aggravated biofouling in laboratory-scale RO systems. In this study, four parallel 4-inch spiral wound RO membranes were used to study the effect of chlorine on biofouling in a pilot-scale RO system. The free chlorine dosages in four experimental groups were 0, 1, 2 and 5 mg/L, respectively. After continuous chlorination and dechlorination, the feed water entered the RO system. It was found that chlorine pretreatment caused a 1.9–36.7% increase in relative feed water pressure of the RO system, suggesting that chlorine aggravated the membrane fouling in the pilot-scale RO system. The microbial community structures of living bacteria in the feed water of the RO system were determined by the PMA (propidium monoazide)-PCR method and showed that the relative abundance of chlorine-resistant bacteria (CRB) was significantly increased after disinfection. Nine major genera which maintained higher relative abundance in experimental groups with high chlorine dosage were considered as possible key species causing membrane fouling, including Pedobacter, Clostridium and Bradyrhizobium.

scholarly journals Modification of used commercial reverse osmosis membranes to nanofiltration modules for the production of mineral-rich packaged drinking water

2020 ◽  
Vol 10 (11) ◽  
Author(s):  
B. Govardhan ◽  
S. Fatima ◽  
M. Madhumala ◽  
S. Sridhar
Keyword(s):  
Drinking Water ◽  
Reverse Osmosis ◽  
Treatment Time ◽  
Operating Time ◽  
Cost Effective ◽  
Chemical Oxidation ◽  
Operating Conditions ◽  
Advanced Technique ◽  
Salt Rejection ◽  
Ro Membrane

Abstract Global supply of commercial reverse osmosis (RO) membranes is growing exponentially due to rapid population growth, industrialization, and urbanization. The continuous demand for enormous quantity of drinking water has brought about process improvements and technological advancements in membrane preparation. The transformation of used RO membranes into nanofiltration (NF) and ultrafiltration membranes by opening up the pores using chemical treatment by inexpensive oxidizing agents could be one of the cost-effective options. The present study investigates the chemical oxidation of the indigenously synthesized RO membrane using aqueous sodium hypochlorite (NaOCl). The performance of the membrane was evaluated by conducting experiments under varying operating conditions of operating time, feed pressure, and total dissolved solids (TDS) in raw water for calculation of flux and salt rejection (%). From an initial flux of 25.2 L/m2 h and TDS rejection of 97.5% for original RO membrane, the values reached 80 L/m2 h and 25.5%, which is in NF range, after a reaction time of 780 min with 4000 ppm concentration of NaOCl oxidizing agent. Further extension of treatment time to 900 min enhanced the flux to 130 L/m2 h with salt rejection lowering to 5.67%. Membrane cleaning was performed efficiently using an advanced technique in which chlorine dioxide (ClO2) was used in combination with citric acid. This combination ensured rapid cleaning with restoration of water flux and % salt rejection. The process was scaled up to pilot plant level using RO membranes modified to NF range of pore size. Permeate water enriched with minerals was further packed using an indigenously designed semi-automatic bottling unit. The studies revealed that the indigenously developed RO membranes are easy to alter into high-performance NF membranes. Overall, the process for production of packaged drinking water was cost-effective, easy to operate, and environmentally friendly.

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