The performance of commercial composite reverse osmosis membranes has been continuously improving, since its introduction in the late seventies. An additional significant improvement of membrane performance has been achieved at the beginning of 1995, when new composite polyamide brackish water RO membrane technology has been introduced. The new membrane material is characterized by a very high ...

Membrane fouling encountered in reclamation of municipal wastewater represents serious design and operational concern. This is because the municipal effluent, after secondary treatment, contains high concentrations of suspended particles, colloids and high level of biological activity. Application of membrane technology for treatment of municipal wastewater requires very extensive pretreatment ...

There are several flow configurations for RO that allow the user to get the most out of the system. This paper will cover a few of the techniques used in RO design to optimize system performance. These techniques include the use of concentrate staging and concentrate recirculation to increase recovery, permeate staging to attain ultrapure standards of separation, and permate throttling and inte...

Free-volume hole-radii of the active skin layer of one seawater and two low pressure reverse osmosis (RO) membranes namely SWC5, ESPAB, and ESPA2 respectively were evaluated using positron annihilation lifetime spectroscopy (PALS) with a slow positron beam. The results were related to the rejection of boric acid and eight N-nitrosamines to provide insights to the transport of these small solute...

Although bentazon is widely used as an agricultural herbicide, it is harmful to humans and poses many environmental threats. This study focused on the treatment of wastewater contaminated with bentazon pesticides using membrane technology. In this regard, low-pressure reverse osmosis (RO) was employed as it has already been used in the removal of other micro-pollutants. The effects of process v...

Reverse osmosis (RO) is a compact process for the removal of ionic and organic pollutants from contaminated water. However, flux decline and rejection deterioration due to concentration polarization and membrane fouling hinders the application of RO technology. In this study, a rotating cylindrical RO membrane is theoretically investigated as a novel method to reduce polarization and fouling. A...

Forward osmosis (FO) is a promising membrane technology to combine seawater desalination and water reuse. More specifically, in a FO-reverse osmosis (RO) hybrid process, high quality water recovered from the wastewater stream is used to dilute seawater before RO treatment. As such, lower desalination energy needs and/or water augmentation can be obtained while delivering safe water for direct p...

one of the most important concerns in tehran municipal landfill is the production of leachate and its potential for water resources pollution, this study was undertaken to examine feasibility of biological and physico/chemical treating of high-strength landfill leachate that was collected from tehran municipal landfill. average cod of the leachate in aerobic submerged membrane bioreactor is 680...

Advances in highly permeable reverse osmosis (RO) membranes have enabled desalting operations, in which it is practically feasible for the applied pressure to approach the osmotic pressure of the exit brine stream. However, energy cost remains a major contributor to the total cost of water produced by RO membrane desalination. Reduction of the overall cost of water production represents a major...