1. Outstanding Resistance to Turbidity and Volumetric Efficiency
  • "HOLLOSEP®" is a reverse osmosis membrane module that allows production of permeate of high purity water by rejection of ions.
  • "HOLLOSEP®"can produce drinking water quality from seawater, and de-mineralized quality water for medicine manufacture from city water and industrial water.
  • Reverse osmosis based on hollow fibers is adopted since sealing the structure is simple without the need for any base material on the permeable water side, no self-contamination is identified in module itself.
  • Hollow fiber is wound efficiently in a cross-wound way without using additional base materials.
  • Millions of hollow fibers are wound into the element construction by a cross winding technique to achieve minimum pressure loss and uniform water flow.
  • The cross winding increases the hollow fiber spacing and improves its fouling resistance to turbidity and provides excellent volumetric efficiency.
  • The simple module structure with high compactness saves installation space.
    Cross-wound Configuration
  • Hollow fiber membrane elements provide about 10 times the surface area compared to spiral wound elements.
  • This greater surface area is a key factor to better tolerate potential fouling in the RO module. If the same amount of fouling material is present in the feed water, the much larger surface area of hollow fiber type membrane will be subjected to much less surface fouling than the spiral wound type membrane.
    2. Bio-fouling Control is Easy and Higher Availability


  • "HOLLOSEP®", Toyobo's hollow fiber membrane produced from cellulose triacetate(CTA) chemistry, offers superior chlorine tolerance compared with polyamide based chemistry membranes.
  • This unique chlorine tolerance allows effective, low cost chlorine injection into the RO module directly as the most superior disinfectant to prevent bio-fouling.
  • Toyobo has demonstrated long term, successful experience in chlorine sterilization at the large Jeddah seawater RO plants in Saudi Arabia. Chlorine injection techniques including quantity and duration can be easily adjusted to meet specific seawater conditions.

  • If seawater is contaminated with biological fouling materials, severe operational problems can occur in the system requiring careful cleaning techniques. Frequently water production decreases in spite of efforts to clean and restore performance
  • Water production uptime or availability for a seawater RO plant is optimized by maintaining consistent performance and minimizing cleaning and maintenance needs.
  • "HOLLOSEP®" RO modules provide opportunity for least complicated engineering design, unique bio-fouling prevention by use of chlorine injection disinfectant, and superior fouling resistance by greater surface area.
  • These benefits deliver the highest availability and lowest cost produce high quality product water.

    3. High Performance and Reliability in Domestic and Overseas Markets Leads to Numerous Deliveries.
  • In domestic markets, "HOLLOSEP®" has been adopted for Fukuoka seawater desalination plant in which the daily production capacity of 50,000 m3/day boasts the largest scale in Japan and the operating recovery of 60% for RO process is one of the highest levels of efficiency in the world.
  • In oversea markets, proven records are exhibited; for example, in Shuqaiq and Jeddah , Saudi Arabia, where high-quality drinking water of 240,000 m3/day and 260,000 m3/day are being produced respectively. These locations are characterized by high-temperature and high-salt concentration seawater that present the tough conditions to the reverse osmosis membrane process.
  • Toyobo's "HOLLOSEP®" RO membrane elements have been selected for use at the Ras Al Khair Plant, which is one of the largest seawater desalination plants in the world, with a capacity of 1,000,000m3 of freshwater per day. Within the total daily output of 1,000,000m3 of freshwater, 345,000m3 is produced by the RO method using Toyobo's RO modules and the remainder is produced by the multi-stage flush (MSF) method.
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    4. Easy Operation and Optimum Maintenance
  • Product water of each RO element in the module can be easily sampled to measure the electrical conductivity.
  • Selection of the RO element for replacement is easy so that maintenance of RO elements can be optimized for long-term operation.
    TOYOBO Membrane Products HOLLOSEP

    HA Series

    HR,HM Series
    HB Series,HJ
    HL Series

    Applications of HOLLOSEP
    HA Series
    HR Series