Optimising molecular simulations of reverse osmosis based concentration processes using molecular replication

Ground water in both the northeastern and southwestern coast areas of Taiwan may contain high concentrations of arsenic. Since no central water supply system is available in some of those areas, point-of-use (POU) water purification devices are considered as an option for providing safe drinking water. In this study, removal of arsenic, using two types of POU purification devices, reverse osmosis (RO) systems and distillers, was investigated. Three commercially available RO systems and two distillers were selected to test their removal efficiency of arsenic from synthetic and real ground water. Experimental results of the three RO systems using synthetic ground water showed that only one system had good removal efficiency for arsenic. In subsequent experiments using real ground water with 0.7 mg l−1 arsenic, only one RO system was able to meet the drinking water standard after producing about 1,000 l of treated water. For the distilling systems, 99% of the arsenic was removed from both synthetic and real ground water. The arsenic concentrations in the finished water of both distillers were all below the standard for drinking water. Although systems with higher arsenic removal efficiency seemed to have better removal of total dissolved solids (TDS), no correlation could be found after analysis.

Role of microbial electrolysis desalination cell in sustainable water and energy management: Performance assessment of platinum and nickel foam cathodes and simulating integration with reverse osmosis systems

Effectiveness of household reverse-osmosis systems in a Western U.S. region with high arsenic in groundwater

Desalting of subsurface water using spiral-wound reverse osmosis (RO) system: technical and economic assessment

Reverse osmosis (RO) technology has been widely applied to water treatment such as seawater desalination, and large RO plants are many in operation around the world. Moreover, much larger plants will be required to secure sufcient water resource in the near future because global water shortage and quality problems are still getting more serious. Mega-ton Water System project was carried out for sustainable management of water environment and for low-carbon path to develop advanced key technologies of water treatment. Lowpressure RO membrane for seawater desalination has been studied in the project as a part of the core technologies to realize mega plant that is capable of producing 1,000,000 m3 of freshwater per day. Fundamental and scientifc research for RO membranes based on fne structure analyses by means of transmission electron microscopy with a special technique was conducted, and practical tools for designing new innovative RO membrane were acquired by the structure analyses to quantify the physicochemical and chemical properties of RO membranes. As the result of studying on structural design of RO membrane, low pressure SWRO membrane was obtained to reduce energy consumption compared to conventional ones in the past of SWRO. The vision of the “Mega-ton Water System” is sustainable desalination and reclamation. The missions are: 1) energy reduction (20-30%), 2) water production cost reduction (50%), and 3) low environmental impact (fewer chemical operations). Water cycle in “Mega-ton Water System” is separated into two parts including i) Seawater RO (SWRO) system, and ii) Seawater RO system with PRO system. The main challenge of development goal is the construction of mega-ton-scale system for seawater desalination for half the current cost. Accordingly, we developed the world’s frst low-pressure, multi-stage, high yield RO system, using a low-pressure seawater desalination membrane, and as a result of incorporating into it the elemental technologies gained from research in subthemes, such as highly-efcient pressure energy recovery, low-cost and highly durable plastic piping, pretreatment without the use of chemicals.

Chapter 2 - Energy Efficiency of Reverse Osmosis

Small-scale reverse osmosis brackish water desalting system combined with greenhouse application for use in remote arid communities

The optimal allocating pumping rate of a multi-well system for a brackish water desalination plant

When there are high and low frequency motions in systems with long and short range forces a judicious choice of reference system leads to very large accelerations in molecular dynamic (MD) simulations. Building on our previous work where we have developed reference system methods for systems with high frequency oscillators, disparate masses, or long range forces, we present a double reference system method which leads to acceleration of as much as 20 in systems consisting of 864 molecules with Lennard-Jones (12-6) forces. Much larger savings should be achieved when this method is applied to longer range forces and larger systems.

Prediction of full-scale filtration plant performance using artificial neural networks based on principal component analysis

Novel design and operational control of integrated ultrafiltration — Reverse osmosis system with RO concentrate backwash

Compositions and constituents of freshwater dissolved organic matter isolated by reverse osmosis

Scarcity of fresh water, forced many countries to get their water needs, or part of it, by means of saline water desalination. Reverse osmosis (RO) systems are useful tools in this concern. In case the grid electricity is not available or costly, photovoltaic (PV) power is necessary to derive RO systems. The present paper is concerned with providing a methodology for complete sizing and design of a photovoltaic reverse osmosis (PVRO) system in Egypt. Egypt has very favorable solar energy. A computer program was constructed to solve the mathematical equations of the model to get the numerical values. The program is capable of calculating the solar irradiation for any city in Egypt. Calculations and selection of the RO system with all connected pumps, the peak PV power needed, and the actual PV area were performed for different water demands ranging from 1-100 m3/day, and various water total dissolved solids (TDSs) of 5000, 15000, and 30000 mg/l. The cost of the complete PVRO system was also determined. The concern of the paper is related to water desalination and solar energy, which are responsible for our existence. The work also aims toward sustainable and clean environment via utilizing solar energy.

Chapter 6 - Important Design and Operation Parameters

Cost evaluation and optimisation of hybrid multi effect distillation and reverse osmosis system for seawater desalination