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.

Production of process water using integrated membrane processes

2006 ◽  
Vol 60 (6) ◽  
Author(s):  
K. Karakulski ◽  
M. Gryta ◽  
M. Sasim
Keyword(s):  
Reverse Osmosis ◽  
Membrane Fouling ◽  
Tap Water ◽  
Industrial Effluents ◽  
Membrane Distillation ◽  
Process Water ◽  
Feed Water ◽  
Reverse Osmosis Membrane ◽  
Permeate Flux ◽  
Membrane Processes

AbstractApplication of ultrafiltration, nanofiltration, reverse osmosis, membrane distillation, and integrated membrane processes for the preparation of process water from natural water or industrial effluents was investigated. A two-stage reverse osmosis plant enabled almost complete removal of solutes from the feed water. High-purity water was prepared using the membrane distillation. However, during this process a rapid membrane fouling and permeate flux decline was observed when the tap water was used as a feed. The precipitation of deposit in the modules was limited by the separation of sparingly soluble salts from the feed water in the nanofiltration. The combined reverse osmosis—membrane distillation process prevented the formation of salt deposits on the membranes employed for the membrane distillation. Ultrafiltration was found to be very effective removing trace amounts of oil from the feed water. Then the ultrafiltration permeate was used for feeding of the remaining membrane modules resulting in the total removal of oil residue contamination. The ultrafiltration allowed producing process water directly from the industrial effluents containing petroleum derivatives.

Design considerations for wastewater treatment by reverse osmosis

2005 ◽  
Vol 51 (6-7) ◽  
pp. 473-482 ◽  
Author(s):  
C.R. Bartels ◽  
M. Wilf ◽  
K. Andes ◽  
J. Iong
Keyword(s):  
Wastewater Treatment ◽  
Calcium Phosphate ◽  
Reverse Osmosis ◽  
Membrane Fouling ◽  
Urban Areas ◽  
Large Scale ◽  
Membrane Surface ◽  
Feed Water ◽  
High Quality ◽  
Quality Water

Reverse Osmosis is finding increasing use for the treatment of municipal and industrial wastewaters due to the growing demand for high quality water in large urban areas. The growing success of membranes in this application is related to improved process designs and improved membrane products. Key factors which have been determined to result in successful operation of large-scale plants will be discussed. Factors which play a key role in the use of RO membranes include ultra or microfiltration pretreatment, low fouling membranes, flux rate, recovery and control of fouling and scaling. In particular, high flux rates can be used when UF or MF pretreatment is used. These technologies remove most of the suspended particles that would normally cause heavy fouling of lead elements. Typically, fluxes in the range of 17–21 lmh lead to cleaning frequencies in the range of 3–4 months. By combining the use of membrane pretreatment and chloramination of the feed water through chlorine addition, two of the primary sources of RO membrane fouling can be controlled. The use of chloramine has become a proven means to control biofouling in a membrane for wastewater applications. The other significant problems for RO membranes result from organics fouling by dissolved organics and scaling due to saturation of marginally soluble salts. The former can be a significant problem for membranes, due to the strong attraction forces. To some extent, these can be mitigated by making the membrane surface more hydrophilic or changing the charge of the membrane surface. To minimize fouling, many plants are turning to low fouling membranes. Extensive studies have demonstrated that the membrane surface is hydrophilic, neutrally charged over a broad pH range, and more resistant to organic adsorption. Also, an analysis of the potential scaling issues will be reviewed. In particular, calcium phosphate has been found to be one of the key scalants that will limit RO system recovery rate. Calcium phosphate concentrations can reach high values in many wastewaters, and scaling of this compound is not often modeled in most RO projection software. Various process options will be presented to evaluate the most economic means of avoiding phosphate scaling. Finally, data from major RO wastewater treatment plants will be presented to show how the RO membranes operate under actual conditions, utilizing many of these design features. Long term data from the 2.6 mgd Bedok demonstration Plant demonstrate that the RO membranes operate consistently on wastewater. Experiences from the 8.5 mgd (32,000 m3/day) Bedok and 10.5 mgd (40,000 m3/day) Kranji plants will also be presented. These large plants started operation in the fall of 2002 and have demonstrated an effective means to reclaim high quality water from difficult source waters, such as municipal wastewaters.

A Novel Dynamic Electromagnetic Heating-Magnetizing Device Used for Reverse Osmosis System

2012 ◽  
Vol 562-564 ◽  
pp. 913-916
Author(s):  
Hai Du ◽  
Yan Bin Qu ◽  
Shu Kang Cheng
Keyword(s):  
Reverse Osmosis ◽  
Mechanical Energy ◽  
Membrane Surface ◽  
Heat Energy ◽  
Feed Water ◽  
Reverse Osmosis Membrane ◽  
Operation Mechanism ◽  
Electromagnetic Heating ◽  
Electromagnetic Field Theory ◽  
The Mathematical Model

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.

The molecular structures of polysaccharides affect their reverse osmosis membrane fouling behaviors

2020 ◽  
pp. 118984
Author(s):  
Yin-Hu Wu ◽  
Xin Tong ◽  
Xue-Hao Zhao ◽  
Yuan Bai ◽  
Nozomu Ikuno ◽  
...  
Keyword(s):  
Reverse Osmosis ◽  
Membrane Fouling ◽  
Molecular Structures ◽  
Reverse Osmosis Membrane
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