Papers by Keyword: Reverse Osmosis (RO)

Abstract: A sequencing batch MBR-RO system has been developed to treat coking wastewater, focusing attention on the COD and TN removal efficiencies. Operational results over 60 days showed that the sequencing batch MBR-RO system had a great impact on removals of COD and TN. the removal efficiencies of COD and TN were 93% and 96% respectively. Final concentrations in the effluent of 0.24 mg phenols/L, 0.02 mg cyanides /L, 28.7 mg COD/L and 4.53 mg TN/L were obtained. In addition, the flux of MBR and RO lost 65.3% and 73.2% respectively.

Abstract: The effects of pressure, concentration and feed temperature using a high pressure membrane filtration test rig capable of handling nanofiltration and reverse osmosis separation was investigated. The experimental results indicated that the applied pressure across the membrane has a significant positive influence on the flux produced and increasing the pressure will rupture the membrane if excessive force or pressure is applied. The high concentrations of solutes/molecules inhibit the flow of fluid through the membrane consequently lower fluxes and improved separation is and subsequently all variables, including their interactions, examined was found to be significant.

Abstract: The purpose of this paper was to investigate the application of ultrafiltration/reverse osmosis (UF/RO) for advanced wastewater treatment. Full-scale tests were set up for investigation in Yuntianhua Co.Ltd, Yunnan, China. The performances of turbidity, residual chlorine, conductivity and various ions were studied. The results suggested that the removal efficiency of turbidity was above 98.20%. Additionally, the average value of Silting Density Index (SDI) and residual chlorine of effluent of UF process were less than 1.80 and 0.06mg/L, respectively. However, its removal efficiency was limited by membrane fouling. And this system needed to be backwashed periodically to maintain high removal efficiency. Hardness and scale-forming ions could be decreased effectively by RO. The RO membrane fouling could be avoided by adjusting pH (7.0-7.5) and dosing scale inhibitor (MDC150, 4.00-5.00mg/L). Finally, the effluent of the UF/RO system can be reused as the cooling water or supply water for low-pressure boiler equipment.

Abstract: 97.5% of the water on Earth is salty, around one percent of that is brackish groundwater, and fresh water is becoming more and more precious. Mature desalination technologies as reverse osmosis, multi-stage flash, multi-effect distillation as well as electrodialysis are introduced in this paper. Of these, such reverse osmosis membranes as cellulose acetate membrane, polyamide membrane and nanomaterials enhanced membrane are discussed. In addition, several seawater desalination processes are presented, and the working manners of three other novel desalination technologies are illustrated. After all, none of the new technologies seem simple and cheap enough to offer much benefit to people, and the appropriate method should be chose according to different nations.

Abstract: A novel, environmental friendly dynamic rotating electromagnetic heating-magnetizing device is proposed, which can heat up and magnetize the low temperature feed water of reverse osmosis system. The device converts input mechanical energy into heat energy completely. The structure and operation mechanism are discussed in detail, and the mathematical model of loss is established based on fundamental electromagnetic field theory. At last, the effects of water magnetization treated by the device are introduced, which inhibits scaling on the reverse osmosis membrane surface and slows down the corrosion of metal surface.

Abstract: This paper describes a novel laboratory technique for characterizing the scale inhibitors performance of reverse osmosis. The experiment was carried out by operating the RO system in a once-through flow mode which was operated by continuous withdrawal of concentrate and permeate. The concentration ratio of reverse osmosis system is calculated by mass or flow or volume of permeate and concentrate. The performance of scale inhibitors was evaluated according to the scale ion concentration of concentrate. The results showed that the method can screen out the performance of anti-scalants quickly and with low error.

Abstract: The water resources of the local west are seriously lacking, and most of water is brackish water with high contains of fluorine quantity. This topic used the RO desalination processing craft to desalt the water in order to provide the drinkable water in the west. The result indicated that the RO brackish water desalination technology is feasible, the quality of desalinated water can meet the national drinking water health standard.

Abstract: In the field of wastewater treatment and water recycling, Concentrates of NF and RO membrane process are the huge issue, which severely hindered wide application of NF and RO system. Therefore, the proper treatments of concentrates are needed. The current work reviewed the disposal method of the concentrates from four aspects: 1) discharge, 2) waste minimization, 3) innocuous treatment, and 4) recycling. The prospects of disposal of concentrates were also analyzed. To some extent, concentrates from NF or RO membrane are the valuable resources. In the further, exploring suitable and highly effective technologies to utilize concentrate as resources is promising.

Abstract: In order to understand the mass transfer process of water molecules in the reverse osmosis membrane based on the dynamic adsorption theory and diffusion transfer concept, according to the theory of random walk, the diffusion-adsorption equation is deduced at the beginning of dynamic adsorption around all diffusion regions. It was studied and analyzed the dynamic adsorption behaviour of H₂O in reverse osmosis membrane of polyamide in the experiment, and the influence of the different temperature to the dynamic adsorption of the reverse osmosis membrane on the early stages was discussed, and calculated the abnormal diffusion index dw. The results showed that the water molecules in this aromatic polyamide type reverse osmosis membrane have the behaviour of abnormal dynamic adsorption, and the higher temperature was, the smaller the abnormal diffusion index dw was.

Abstract: In order to adapt to the development of world integration, most modern ocean-going vessels are engaged in long transport routes voyages, so the demand for fresh water is very large. From the energy conservation, improving the amount of water production, saving shipping companies operating costs, increasing ship endurance capacity point of view, combine the vacuum system which has the feature of less salt content with the reverse osmosis water production system which has the advantage of large water production, now we design the new type composite desalination plant, and doing the model calculation, the study has a very high prospects for the development and practical application value.