The Study on the Effect on Seawater Desalination and Boron Removal by Ro-EDI Desalination System

2014 ◽  
Vol 955-959 ◽  
pp. 3211-3215
Author(s):  
Zhao Ji Hu ◽  
Yi Liang Hu ◽  
Er Ming Ouyang ◽  
Fei Feng
Keyword(s):  
Water Quality ◽  
Reverse Osmosis ◽  
Boron Concentration ◽  
Total Dissolved Solids ◽  
Feed Water ◽  
Boron Removal ◽  
Experimental Parameters ◽  
Product Water ◽  
Simulated Seawater ◽  
Process Coupling

A hybrid process coupling reverse osmosis (RO) with electrodeionization (EDI) was investigated to remove TDS and boron from simulated seawater in this study. The effects of applied total dissolved solids (TDS) and the concentration of boron in the feed water on product water quality were investigated. According to the results obtained, the TDS of the product water increased when a high applied TDS in the feed water; however, all of the TDS of the product were complying with relevant standards within experimental parameters. When the boron concentration was below 5.64mg/L in the feed water, the boron concentration of the product water was complying with relevant standards.

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).

Research into the corrosion behavior of carbon steel in simulated reverse osmosis product water and seawater using a wire beam electrode

2015 ◽  
Vol 62 (3) ◽  
pp. 176-181
Author(s):  
Min Zhang ◽  
Hong-Hua Ge ◽  
Xue-Juan Wang ◽  
Xin-Jing Meng ◽  
Yu-Zeng Zhao ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Reverse Osmosis ◽  
Corrosion Behavior ◽  
Corrosion Potential ◽  
Potential Difference ◽  
Cathode Potential ◽  
Anode Potential ◽  
Content Type ◽  
Product Water ◽  
Simulated Seawater

Purpose – The purpose of this study was to explore the differences in the corrosion behavior of carbon steel in simulated reverse osmosis (RO) product water, and in seawater. Design/methodology/approach – The wire beam electrodes (WBE) and coupons made from Type Q235 carbon steel and were immersed in simulated reverse osmosis product water, and in seawater, for fifteen days. The corrosion potential distribution on the WBE at different times was measured. The corrosion rates of the carbon steel in different solutions were obtained using weight loss determinations. The different corrosion behavior of carbon steel in the two kinds of solution was analyzed. Findings – The results showed that the average corrosion potential, micro-cathode potential and micro-anode potential of the WBE decreased with time in simulated RO product water. During this period, the maximum potential difference between micro-cathodes and micro-anodes on the WBE surface also decreased with time. The potential difference was more than 260mV at the beginning of the test and was still greater than 110mV after fifteen days of immersion. The positions of cathodes and anodes remained basically unchanged and corrosion took place on the localized anode during the experiments. The average corrosion potential, micro-cathode potential and micro-anode potential on the WBE surface also decreased with time in the simulated seawater. However, the maximum potential difference between micro-cathode and micro-anode on the WBE surface in the simulated seawater was much smaller than was the case in simulated RO product water. It was 37.8 mV at the beginning of the test and was no more than 12mV after two days immersion. The positions of cathode region and anode kept changing, leading to overall uniform corrosion. The actual corrosion rate on the corroded anode region in simulated RO product water was greater than was the case in simulated seawater. Originality/value – The corrosion behavior differences of carbon steel between in RO product water and in seawater were revealed by using wire beam electrodes (WBE). From the micro point of view, it explained the reason why the actual corrosion rate of carbon steel in RO product water was greater than that in sea water. The results can be helpful to explore future corrosion control methods for carbon steel in RO product water.

scholarly journals A new technique to purify biologically treated wastewater by reverse osmosis: utilization of concentrate

Vestnik MGSU ◽  
2020 ◽  
pp. 688-700
Author(s):  
Aleksei G. Pervov ◽  
Konstantin V. Tikhonov
Keyword(s):  
Wastewater Treatment ◽  
Reverse Osmosis ◽  
Biological Treatment ◽  
Municipal Wastewater ◽  
Ammonia Concentration ◽  
Treated Wastewater ◽  
Feed Water ◽  
Working Pressure ◽  
Membrane Area ◽  
Product Water

Introduction. Possibilities to purify municipal wastewater using reverse osmosis membrane techniques are investigated aimed at production of quality water for industrial use or meeting regulations for surface water sources discharge. A new eveloped tools to utilize concentrate effluents by reducing its flow by a value that does not exceed 0.5–1.0 per cent of initial feed water flow and it’s withdrawal of all rejected impurities together with dewatered sludge as a sludge moisture. Objectives: development of reverse osmosis techniques to purify wastewater after biological treatment; evaluation of possibilities to radically reduce concentrate flow to withdraw it together with activated sludge as it’s moisture.  Materials and methods. Experimental research is conducted to develop membrane operational modes during wastewater treatment. Experimental procedure is developed and described to evaluate reduction of membrane rejection of dissolved impurities and product flow decrease during experimental wastewater treatment and concentrate utilization test run.  Results. The basic equations are derived that enable us to determine: the required concentrate flow value that corresponds to concentration values of COD and suspended solids values in the feed water; the required values of membrane recoveries that correspond to ammonia concentration in the feed water to meet required regulation values in the product water. The tools to evaluate membrane area and a number of membrane modules are developed and described. Optimum values of the working pressure are evaluated as well as other economic parameters are presented to compare the developed techniques with biological treatment. Conclusions. To reach the required ammonia concentration in product water, double stage treatment of feed water with low-pressure reverse osmosis membranes is required. Influence of dissolved organics defined as COD, on membrane performance. The optimum value of working pressure is determined which is 7.5–8 Bars.

Kristal® 2000 PVDF hollow fiber UF membrane in the pretreatment for seawater desalination

2012 ◽  
Vol 7 (4) ◽  
Author(s):  
Zanguo Peng ◽  
Zhaoxuan Zhang ◽  
Pandurangan Mohan ◽  
Kasinathan Manimaran ◽  
Dongfei Li
Keyword(s):  
Water Quality ◽  
Pilot Study ◽  
Reverse Osmosis ◽  
Hollow Fiber ◽  
Large Scale ◽  
Operating Costs ◽  
Feed Water ◽  
Seawater Desalination ◽  
Seawater Reverse Osmosis ◽  
Uf Membranes

Membrane technology has emerged as a dominant solution to seawater desalination due to its superior advantages such as stable output water quality, lower energy consumption, ease of operation and smaller footprint. However, the design of spiral wound reverse osmosis (RO) membranes used in desalination does not allow for backwash or air scouring, thus rendering the RO membrane highly susceptible to fouling. Pretreatment for the RO system is therefore essential to ensure a long service life of the RO membranes. For waters containing suspended solids of up to 75 mg/L (such as that in the SingSpring Desalination Plant at Tuas, Singapore), conventional pretreatment methods (such as dissolved air floatation and filtration (DAFF), chemical dosing and cartridge filtration) require regular operator intervention to produce a permeate of reasonably quality. Ultrafiltration (UF) as a pretreatment for seawater desalination can offer better treated water, lower operating costs, a smaller footprint, and flexibility in dealing with poor or varying feed water quality. By improving the pretreatment permeate water quality, reducing operating costs and the footprint, capital expenses can be lowered. Greater stability is also achieved during times of poor or variable feed water conditions (such as periods of algalbloom). A pilot study was conducted at SingSpring to track the performance of Hyflux's Kristal® 2000 hollow fiber UF membranes as pretreatment for the seawater reverse osmosis (SWRO) system. The results of the pilot study will enable the design of future large-scale UF-SWRO membrane projects for seawater desalination.

Boiler-Water Treatment by Reverse Osmosis Employing Solar Energy

2011 ◽  
Vol 374-377 ◽  
pp. 1021-1024
Author(s):  
Xian Qiu Zhang ◽  
Jing Feng Xu ◽  
Ming Xia Du ◽  
Yong Zhang
Keyword(s):  
Water Quality ◽  
Water Treatment ◽  
Solar Energy ◽  
Reverse Osmosis ◽  
Quality Standard ◽  
Experimental Results ◽  
Feed Water ◽  
Steam Boiler ◽  
Boiler Water ◽  
Operation Pressure

A boiler-water treatment device main composed of solar energy heater and reverse osmosis was designed Experiments on permeation flow and water quality as functions of temperature caused by solar energy were conducted. The experimental results showed that when the operation pressure was kept at 0.9MPa, permeation flow could increase 35.5%, from 6.5L/min to 8.8L/min if the feed water temperature increased from 18°C to 38°C by solar energy; and the produced water could totally meet Chinese water quality standard for middle or low pressure steam-boiler. On the other hand, if the permeation flow was kept at 8 L/min, the operation pressure would drop by 32.2%, from 1.18MPa to 0.78MPa. Based on these experimental results, economic and environmental analysis on a case of 10m3/h boiler-water treatment device by reverse osmosis employing solar energy were conducted, the results shows great significance for energy saving and environmental pollutants cut. All this showed this new RO system with pre-heating the feed water by solar energy could be widely applied in boiler-water treatment.

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