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The concentrating of alizarin using a reverse osmosis process
S. S. MADAENI,H. DANESHVAR
Journal of the Serbian Chemical Society , 2005,
Abstract: Membrane technologies in general and reverse osmosis in particular have been employed for the concentrating of solutions. In this study, the concentrating of a heat sensitive alizarin extracted from madder root was realized using an FT30 reverse osmosis membrane. The effects of cross flow velocity, transmembrane pressure and pH on the flux and rejection were studied. Increasing the transmembrane pressure increased the flux while the rejection was constant. At pH 7 8, the highest flux was achieved. This study showed that reverse osmosis is the process of choice for the concentrating of alizarin solutions. The optimum operating conditions were 1.0 m/s crossflow velocity, 16 bars transmembrane pressure and pH 7. The system was tested for 12 h without severe fouling problems.
Preparation of Hollow Fibre Composite Reverse Osmosis Membrane  [cached]
Fengjuan Li,Wei Wang,Qiang Ren
Modern Applied Science , 2009, DOI: 10.5539/mas.v4n1p82
Abstract: A novel thin-?lm composite (TFC) reverse osmosis (RO) membrane was developed by the interfacial polymerization (IP) of trimesoyl chloride (TMC) and m-phenylene diamine (MPD) on the hollow fibre ultrafiltration polysulphone (PS) membrane. The performance of the TFC membrane was optimized by studying the preparation parameters, which included monomer TMC concentration, monomer MPD concentration and alcohol additive in aqueous solution. The reverse osmosis performance of the resulting membrane was evaluated through permeation experiment with 1000 ppm NaCl at 0.7 MPa. The results showed that the optimum concentration of MPD and TMC were 0.5wt% and 3g/L, respectively. To improve flux, alcohol was added to the aqueous phase, when certain concentration of alcohol was added to the aqueous solution, the flux of the prepared membrane increased from 5.0 to 9.1 L/(m2·h) without loss in salt rejection. The properties and structures of skin layer of RO composite membranes were characterized by AFM. It was found that IP had occurred and the separation layer was formed, and the novel reverse osmosis membrane appears to comprise a thicker, smoother and less cross-linking film structure. Additionally, the TFC membrane exhibits good long-term stability.
Evaluation of the acerola juice concentrated by reverse osmosis
Gomes, Eliane Rodrigues dos Santos;Mendes, Elisabete Scolin;Pereira, Nehemias Curvelo;Barros, Sueli Teresa Davantel de;
Brazilian Archives of Biology and Technology , 2005, DOI: 10.1590/S1516-89132005000400022
Abstract: the aim of this study was to obtain the acerola juice using separation processes with membranes. the acerola pulp was initially defrosted and treated with 100 ppm of citrozym ultra l enzyme at 45oc for one hour, then ultrafiltrated at 3 bar at 45oc using 0.1 μm ceramic membrane, and concentrated by reverse osmosis using a spiral membrane of a compound film. the pressures on the reverse osmosis were 20, 30, and 40 bar at environmental temperature, thus, resulting a juice with 9.76, 14.56, and 17.36 obrix, respectively. the physicochemical characteristics of the juice were preserved and, studies on evaluation of the public acceptability, showed that 75% of the consumers liked the juice.
Heavy metal removal using reverse osmosis  [PDF]
Tomá? Bakalár,Milan Búgel,Lucia Gajdo?ová
Acta Montanistica Slovaca , 2009,
Abstract: The aim of this work was to study reverse osmosis characteristics for copper, nickel and zinc removal from technological aqueoussolutions. Reverse osmosis (RO) is a separation process that uses pressure to force a solution through a membrane that retainsthe solute on one side and allows the pure solvent to pass to the other side. A polyamide thin-film composite membrane TW30-1812-50was used. The difference in flux decline is significant. There is a significant difference in flux decline depending on the anions of usedheavy metal salts. The heavy metal concentration also has a significant influence on the membrane separation. There is alsoa significant difference in flux decline depending on the transmembrane pressure.
Nitrate-nitrogen removal with small-scale reverse osmosis, electrodialysis and ion-exchange units in rural areas
JJ Schoeman
Water SA , 2009,
Abstract: The nitrate-nitrogen concentration in water supplied to clinics in Limpopo Province is too high to be fit for human consumption (35 to 75 mg/. NO3-N). Therefore, small-scale technologies (reverse osmosis, ion-exchange and electrodialysis) were evaluated for nitrate-nitrogen removal to make the water potable (< 10 mg/. NO3-N). It was found that the reverse osmosis process should function well for nitrate-nitrogen removal. Nitrate-nitrogen could be reduced from a concentration of 35 to 43 mg/. in 1 case to a concentration of between 1.4 and 5.5 mg/. in the treated water. In another case it could be reduced from 54 to 72 mg/. to 12 to 17 mg/. in the treated water. The water was also effectively desalinated. The ion-exchange process could also reduce the nitrate-nitrogen concentration to less than 10 mg/. in the treated water. However, the water could not be efficiently desalinated and the process should function better when the level of total dissolved solids in the feed is not very high. The electrodialysis process should also function well for nitrate-nitrogen and salinity removal. However, the electrodialysis process is more complicated to operate. The reverse osmosis and ion-exchange processes are therefore suggested for nitrate-nitrogen removal at clinics. Capital costs for small-scale reverse osmosis and ion-exchange units are estimated at ZAR7 000 and ZAR10 000, respectively. Operational costs for reverse osmosis and ion-exchange are estimated at ZAR3.16/m3 and ZAR3.60/m3 of treated water, respectively.
Nitrate-nitrogen removal with small-scale reverse osmosis, electrodialysis and ion-exchange units in rural areas
JJ Schoeman
Water SA , 2009,
Abstract: The nitrate-nitrogen concentration in water supplied to clinics in Limpopo Province is too high to be fit for human consumption (35 to 75 mg/ NO3-N). Therefore, small-scale technologies (reverse osmosis, ion-exchange and electrodialysis) were evaluated for nitrate-nitrogen removal to make the water potable (< 10 mg/ NO3-N). It was found that the reverse osmosis process should function well for nitrate-nitrogen removal. Nitrate-nitrogen could be reduced from a concentration of 35 to 43 mg/ in 1 case to a concentration of between 1.4 and 5.5 mg/ in the treated water. In another case it could be reduced from 54 to 72 mg/ to 12 to 17 mg/ in the treated water. The water was also effectively desalinated. The ion-exchange process could also reduce the nitrate-nitrogen concentration to less than 10 mg/ in the treated water. However, the water could not be efficiently desalinated and the process should function better when the level of total dissolved solids in the feed is not very high. The electrodialysis process should also function well for nitrate-nitrogen and salinity removal. However, the electrodialysis process is more complicated to operate. The reverse osmosis and ion-exchange processes are therefore suggested for nitrate-nitrogen removal at clinics. Capital costs for small-scale reverse osmosis and ion-exchange units are estimated at ZAR7 000 and ZAR10 000, respectively. Operational costs for reverse osmosis and ion-exchange are estimated at ZAR3.16/m3 and ZAR3.60/m3 of treated water, respectively.
Research Progress of Brackish Water Desalination by Reverse Osmosis  [PDF]
Pan Zhang, Jingtao Hu, Wei Li, Houbo Qi
Journal of Water Resource and Protection (JWARP) , 2013, DOI: 10.4236/jwarp.2013.53031
Abstract:

Brackish water (BW) desalination is a primary path to relieve the shortage of water. As one of the BW desalination methods, reverse osmosis (RO) technology has advantage for both technology and process procedure. The expounding of this research studied or reviewed recent years, reverse osmosis membrane, energy recovery, new energy and application technology in BW desalination of RO at home and abroad. Wind power and solar energy can be combined with energy recovery device for RO. The research also explains that BW desalination by RO is practical and feasible in some areas in China.

Obtaining water with a high degree of purity by using reverse osmosis
Nicolae Chiril?
Scientific Bulletin of the ''Petru Maior" University of T?rgu Mure? , 2011,
Abstract: In this paper, we used the method of reverse osmosis in order to obtain water with a high degree of purity. For this aim, we used the TKA 20-120ECO device. We completed physic-chemical determinations for the water of supply, as well as for the water obtained after the osmosis process. The results that we obtained are relevant and interesting.
Concentration of pineapple juice by reverse osmosis: physicochemical characteristics and consumer acceptance
Couto, Daniel Sim?es;Cabral, Lourdes Maria Corrêa;Matta, Virgínia Martins da;Deliza, Rosires;Freitas, Daniela de Grandi Castro;
Ciência e Tecnologia de Alimentos , 2011, DOI: 10.1590/S0101-20612011000400012
Abstract: reverse osmosis has been used for the concentration of fruit juices with promising considering the quality of the obtained products. the objective of this study was to concentrate single strength pineapple juice by reverse osmosis. the concentration was carried out with polyamide composite membranes in a 0.65 m2 plate and frame module at 60 bar transmembrane pressure at 20 °c. the permeate flux was 17 l.hm-2. the total soluble solid content of the juice increased from 11 to 31 °brix corresponding to a volumetric concentration factor (vcf) of 2.9. the concentration of soluble solids, total solids, and total acidity increased proportionally to fcv. the concentrated juice and three commercial concentrated pineapple juices were evaluated regarding preference and purchase intention by 79 pineapple juice consumers. the concentrated juice by reverse osmosis was the preferred among consumers. it can be concluded that this process may be considered an alternative to the pre-concentration of fruit juices.
EFFICIENCY OF DOMESTIC REVERSE OSMOSIS IN REMOVAL OF TRIHALOMETHANES FROM DRINKING WATER  [PDF]
S. Mazloomi ? R. Nabizadeh ? S. Nasseri ? K. Naddafi ? S. Nazmara ? A. H. Mahvi
Iranian Journal of Environmental Health Science & Engineering , 2009,
Abstract: The reaction of disinfectants with natural organic matters existing in water lead to the formation of Disinfection By-Products. Potentially hazardous and carcinogenic characteristics of trihalomethanes (THMs) are recognized. Thus removal of THMs or its precursors are necessary for human health. The aim of this study was to study the efficiency of domestic reverse osmosis (RO) in removal of trihalomethanes from drinking water. A pilot scale of RO system with Polyamide membrane as Spiral-Wound, Tape wrapping module was used. Feed solution was made by using of pure chloroform. The samples containing chloroform were analyzed using a gas chromatograph equipped with a flame ionization detector. By increasing the flow, the removal rate of chloroform decreased and with declining removal of EC, the removal of chloroform declined too. In this research, at the worst condition, the efficiency of the pilot scale reverse osmosis reached to 80 % removal of chloroform.
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