Santa Barbara, Curacao desalination plant expansion using NanoH sub(2)O thin film nanocomposite (TFN) SWRO membrane

• Published in: Desalination and water treatment 2015-08, Vol.55 (9), p.2446-2452
• Main Authors: Kim-Hak, David, Dixon, Mike B, Galan, Manuel A, Boisseau, Frank, Gallastegui, Joseba, Martina, Ralph
• Format: Article
• Language: English
• Subjects: Blends; Desalination; Design engineering; Flux; Islands; Membranes; Nanostructure; Pressure vessels; Thin films
• ISSN: 1944-3994; 1944-3986
• DOI: 10.1080/19443994.2014.939859

The Santa Barbara desalination plant, located in the South of the Curacao Island, was built and commissioned by Degremont in 2005. The plant production capacity was 18,000 m super(3)/d-consisting of three double-pass trains-which supplied about 45% of the average drinking water consumption of the Island. However, to fulfill the increasing demand of potable water, the plant owner, Aqualectra, added a fourth train to produce 7,100 m super(3)/d, totaling a production capacity to 25,100 m super(3)/d. The new train is single-pass and its product blends with the product from the other three trains. Based on an innovative technical approach, Aqualectra and Degremont awarded NanoH sub(2)O the supply of the seawater RO membranes for the fourth train. The proposed membrane design by NanoH sub(2)O offered the following: (i) 29% less SWRO elements per train than the existing first-pass trains; reducing the number of pressure vessels from 92 to 65; (ii) the same operating feed pressure as the existing first-pass trains while the system flux is significantly higher; (iii) better product quality than the first-pass product from the existing trains. The membrane design consists of a hybrid design where two low-flux (6,500 gpd) elements, Qfx SW 400SR and five higher flux (9,000 gpd) elements, Qfx SW 400R are internally staged within the pressure vessels. The new train was commissioned in September 2012 and accepted by Aqualectra the following month. After more than one year of continuous operation, the train performance has been stable and meets all of Aqualectra's requirements. The product has delivered a TDS concentration below 300 ppm. This represents a 40% product quality improvement when compared with the first-pass of the original three trains that carry older competitor membranes. This installation showcases the potential benefits of using low and higher flux membrane in a hybrid configuration to significantly increase the system flux, and lower capital and operational expenses when compared with traditional designs with conventional membranes.