subject: Industrial Seawater Ro System Aysir Tourism Resort In Turkey [print this page] In 2004, Pure Aqua, IncIn 2004, Pure Aqua, Inc. manufactured and supplied an industrial seawater reverse osmosis (RO) system for the Aysir Tourism Resort in Turkey. The system consists of two independent units with a total capacity of400m3per day of product water.
The system consists of two independent units with a total capacity of 400m3per day of product water. Prior toPure Aqua's involvement, RO pilot installations had been employed on thesite with limited success. Membranes became fouled and/or scaled, and the owners were not convinced that the RO equipment would provide adependable long-term water supply for the property. Shipping potable water by truck became a likely means of supplying the resort.
Background
Because of the Aysir Tourism Resort's location, city or municipal water was not available. In addition, because of the resort's close proximity to the sea,well water in the area was 40,000 ppm or more TDS. It was estimated that the resort would need as much as 400 m3per day to meet its potable and irrigation water needs. After careful analysis of the resort's needs and location, the technical staff of Pure Aqua, Inc., a manufacturer and wholesale distributor of RO systems and components for industrial and commercial applications located in Irvine, California, decided that a seawater RO was the most effective and efficient method of obtaining the quality and quantity of water necessary for the resort's daily operations.
System & Process
The feed water to the system was supplied from a beach-well with raw water TDS of about 40,000 ppm.The system design was based on high rejection TFC spiral wound membranes with an energy recovery turbine.The seawater RO systems were selected from Pure Aqua's SWI Series. Each produces 200 m3per day of drinking water with TDS less than 300 mg/L. In addition, Pure Aqua proposed enhancing pretreatment to the RO system. Itwas recommended that chlorine be injected into the feed for disinfection. Acid was then added to lower pH and minimize calcium precipitation. After media filtration, sodium bisulfite was injected to remove residual chlorine, which if present, is harmful to RO membrane elements. Finally,1-2 ppm antiscalant was added to the feed just prior to the cartridge filters on the RO skids.This pretreatment scheme addressed the concerns presented by the feed water analysis and previous pilot tests. It was also proposed that pretreatment equipment functions should be measured / monitored by a touch panel that controlled the RO system.The overall process is briefly described below.
Pretreatment of raw water includes:
-Chlorination to prevent bacterial growth in piping
-Acid injection to prevent calcium precipitation
-Filtration using conventional media filters to reduce suspended solids (SS) to 10-micron size
-Dechlorination by addition of sodium bisulfite to remove Free Chlorine in the feed water
-Antiscalant injection to prevent membrane fouling.
The pretreatment was adopted inconjunction with the RO equipment. The seawater RO units consist ofthe following:
-Feed and backwash pumps
-5-micron cartridge filters to reduce feed water silt density index (SDI) and to limit the SS to 5-micron size
-Seawater RO membranes feed high pressure pumps
-TFC spiral wound membranes to reduce the TDS from 40,000 mg/L to less than 300 mg/L
-Seawater RO flushing and clean-ing system to maintain the membrane performance
-Touch-screen programmable logic control-based control panel
-Energy recovery turbine (recovering up to 35% ofthe energy consumption) and variable frequency drive.
Performance
The desalination plant produces 2 x 200 m3per day of drinking water with TDS less than 300 mg/L from feed water with a TDS of about 40,000 mg/L at temperature range of19 to 27C.Trials concluded that acid injection could be suspended without affecting the operations of the plant. From its initial start-up in 2004,the plant has been running smoothly with minimal trouble-shooting. As a result, the resort has a reliable and steady supply of potable water at a cost far less than shipping water to the site.
