Semiconductor industry requires ultrapure chemicals to manufacture microelectronic devices. Hydrogen peroxide is one of the most demanded chemical by the semiconductor industry and ultrapurification processes are needed to achieve the electronic grade requirements for this chemical. Among all the ultrapurification alternatives, reverse osmosis emerges as the most desirable option according to e...

Akin type (asymmetric) reverse osmosis membranes undergo an irreversible osmotic dehydration upon coming into contact (skin side) with salt solutions. The extent of consequent changes (in appearance; decrease in linear dimension, water flux and salt rejection) are dependent on the salt concentration. These observations are correlated with the expected morphological changes taking place duri...

Reducing the energy consumption of membrane desalination is critical to reducing its cost of water and minimizing desalination’s CO2 emissions. Hybrids of reverse osmosis (RO) with ultrapermeable membranes promise to address the efficiency, rejection, and fouling issues. In a batch reverse osmosis (BRO) process, salinity is varied over time so that the applied pressure better matches osmotic pr...

In this report, experimental investigation of waste water treatment by reverse osmosis to enable its reuse in cooling tower is presented. A polyamide spiral wound RO membrane followed by three filters as RO pretreatment (two activated carbon and one cartridge filter) and samples of Tehran refinery treated waste water have been used. The effect of operating conditions such as pressure difference...

Over the past half century, reverse osmosis (RO) has grown from a nascent niche technology into most versatile and effective desalination advanced water treatment available. However

Seawater desalination, the desalination of waters flowing back from hydraulic fracturing processes and brackish water desalination constitute important desalination applications. These have a combined market size in excess of $25 billion per annum and a combined water production rate equivalent to the domestic consumption of over 300 million people. Each application offers its own distinct chal...

An optimal control of Reverse Osmosis (RO) plant is studied in this paper utilizing the auto tuning concept in conjunction with PID controller. A control scheme composing an auto tuning stochastic technique based on an improved Genetic Algorithm (GA) is proposed. For better evaluation of the process in GA, objective function defined newly in sense of root mean square error has been used. Also i...

The presently used hollow fiber membrane modules consist of a bundle of fibers in a cylindrical polymer or metal shell parallel to the shell axis. The feed solution flows either through the lumen or at the outside parallel to the fibers. This paper compares the performance of these modules with a new transverse flow module where the hollow fibers are positioned perpendicularly to the flow direc...