Molina V.G.,MBH Solutions |
Casanas A.,Dow Iberica S.L.
Desalination | Year: 2010
Water is becoming day by day a more precious and even scarce natural resource. In Europe, water shortage or water stress is notable in countries such as Spain, Turkey, Italy, Greece, etc., where rainfalls are few, irregular and inconsistent. In order to improve the use of the Spanish hydrologic resources and to satisfy the higher water demand due to, not only tourism but also agriculture and increased population, the Spanish Government has been promoting over the last years different strategies. In July 2005, a new Act (National Hydrologic Plan) was passed, which included more than one hundred immediate points of action to improve the existing water-related infrastructures and to construct new desalination plants. In addition, in December 2007, a Royal Decree was approved in order to regulate and to promote water reuse applications in the country. Reverse Osmosis is currently taking a fundamental role in seawater and brackish water desalination as well as in water reuse installations. In this paper, the current situation of Spain in terms of water resources is reviewed, the performance of some Reverse Osmosis plants already in operation is documented and the latest key innovations of Reverse Osmosis such as recently developed modules, new configurations and modules with larger diameter are described. © 2009 Elsevier B.V. All rights reserved.
Garcia-Molina V.,MBH Solutions |
Chang R.,Dow Chemical Company |
Busch M.,MBH Solutions
Desalination and Water Treatment | Year: 2010
The aim of this article is to describe the long term performance of one of the first Seawater Reverse Osmosis desalination plants with Ultrafiltration as pre-treatment. The plant in question is located in Magong (Taiwan) and has a current capacity of 5,500 m3/day. In the near future this current capacity will be increased up to 13,000 m3/day. The Magong desalination plant is an important example of how Ultrafiltration is a key component in seawater desalination plants to ensure sustainable and reliable operation of the downstream reverse osmosis installation. When the Magong desalination plant was initially started-up in 2002 it had a conventional pre-treatment. After six years of less than satisfactory performance, the conventional pre-treatment was replaced by a Ultrafiltration system. Nowadays the plant consists of a self-cleaning Filter, the Ultrafiltration units, Cartridge Filter and Reverse Osmosis lines. The Ultrafiltration system contains 7 racks, each with 60 modules DOW™ Ultrafiltration SFP2860. The Reverse Osmosis installation consists of a first pass using FILMTEC™ SW30HRLE-400 membranes and a second pass using FILMTEC™ LE-400 membranes. During the first year of operation of the integrated system (UF + RO), the modus operandi of the Ultrafiltration has been optimized in order to ensure smooth operation and low chemical consumption. Thanks to this optimization the filtrate produced is of extremely good quality in terms of turbidity and the measured values of SDI15 and MFI0.45-15 have been constantly below 2.1. Additionally, as a result of this optimization and of the stable performance of the Ultrafiltration, the Reverse Osmosis units have been operating according to the expectations, i.e., very low permeate flow loss over the first twelve months and perfectly achieved quality requirements. More in detail, the current Fouling Factor in all three Reverse Osmosis lines is around 0.85 and the salt content in the permeate is approximately 40% lower than the predicted value. It should be also emphasized that the Reverse Osmosis installation has been successfully run at a flux of 17-18 L/m2h, which is much higher than the flux that a conventional pretreatment would have permitted. © 2010 Desalination Publications.
Majamaa K.,MBH Solutions |
Aerts P.E.M.,MBH Solutions |
Groot C.,Dow Chemical Company |
Paping L.L.M.J.,Dow Chemical Company |
And 3 more authors.
Desalination and Water Treatment | Year: 2010
The DECO water treatment facility (built and operated by Evides Industriewater B.V.) is using an integrated membrane system to produce demineralised water for the production facilities of Dow Benelux B.V in Terneuzen, the Netherlands. The system consists of large-scale continuous microfiltration (CMF) unit and two-pass reverse osmosis (RO) unit with FILMTEC™ membranes. It is the first time in the Netherlands that domestic waste water is re-used in such a large scale for industrial use. This is an excellent example of a full scale process which was adjusted to preserve scarce fresh water resources in the region. The main goal-to minimize the environmental impact and to maximize water recovery through water recycling loops, thereby supporting the chemical industry movement to improve sustainability. This paper discusses the operational experience of the first 18 months operation with wastewater. The plant was started in 2000 and was originally designed to desalinate estuary water, due the lack of fresh water in the region. The water source was challenging due to high chemical and biological variability, which lead to operational difficulties like biofouling and high maintenance costs due to corrosion. In 2006 the plant was re-engineered to treat municipal waste water originating from the nearby city of Terneuzen. Re-engineering consisted of new RO membrane design,low pressure feed pumps and process automation adjustments. The DECO plant uses fouling resistant membranes (BW30-400/34i- FR) with a thick feed spacer. The spacer reduces the fouling potential and facilitates cleaning. In addition, the plant is using frequent preventive cleanings, which is only possible with robust membranes. These actions have led to stabile operation in terms of permeate flow and the good quality of the produced permeate (<10 μS/cm). This case shows that operational problems caused by the biologically active wastewater can be eliminated by a good plant design (membrane selection) and good operational practices. The facility reports significant savings, 20% increase in the system recovery and 50% reduction in the operational cost (OPEX) with the implementation of the waste water treated system. The savings in OPEX are mainly related to energy costs and decreased use of chemicals for water treatment. In addition, the environmental impact is reduced as the city's waste water is no longer discharged to the sea, but given another life as process water. © 2010 Desalination Publications. All rights reserved.