Press Releases


December 22, 2009

Kurita Develops Water Treatment Chemicals to Contribute to the Stabilization of RO Membrane Processing

Kurita Water Industries Ltd. (Head Office: Shinjuku-ku Tokyo, President: Hiroshi Saito) has developed and begun selling three new water treatment chemicals that contribute to the stabilization of reverse osmosis (RO) membrane processing:

  1. Pretreatment coagulant to effectively eliminate organic substances that degrade filtration capacity
  2. Slime control agent to effectively eliminate slime that causes fouling of the RO membrane
  3. Highly functional scale inhibitor that inhibits the formation of scale such as silica and calcium.

With these water treatment chemicals for RO membrane processes, Kurita has reinforced its capacity to help our customers achieve consistent water quality, reduce maintenance work, and cut overall costs related to RO membrane systems.

In the future, RO membranes will be used worldwide in the reclamation of waste water and seawater desalination. In anticipation of this, Kurita will intensify its development of RO membrane-related water treatment chemicals in an effort to expand our share of this growing market.

  1. Notes:

    Slime: Contaminant formed by microbes such as underwater bacteria and algae

    Scale: Calcium or silica solid precipitated from water

1. Background

  1. RO membranes are used to remove ionized or organic substances from water. They are used mainly in fields in which ultra pure water is required, such as the manufacture of semiconductors and liquid crystals, as well as in the reclamation of waste water from industrial processes and in seawater desalination plants. Recently, however, a decline in the quality of raw water has resulted in the sliming, scaling, and fouling of RO membranes, leading to reductions in the amount and quality of the permeated water. As a result, factories and plants using RO membrane systems have been forced to engage in more frequent cleaning and replacement of membranes, which has pushed up their costs.
  2. As worldwide demand for clean water grows, there is an increasing need for seawater desalination in China and the Middle East and for the reclamation of waste water in Asian countries. In line with this, the market for RO membranes is also expanding at a rapid pace.

2. Kurita's approach

Kurita has a long history of delivering a range of RO membrane systems for water treatment facilities, focusing on ultra pure water production systems for the semiconductor industry and facilities for waste water reclamation and seawater desalination industries. Drawing upon our many achievements and rich experience in this field, we have successfully developed unique water treatment chemicals that can enhance the stability of RO membrane processing.

3. Kurita's RO membrane treatment chemicals

After measuring the quality of the raw water and diagnosis of our customers' RO membrane systems, Kurita proposes the optimal combination of water treatment chemicals to help stabilize the systems. Note that newly developed products should be used at specific points in the standard water treatment process.

1. Pretreatment coagulants Kuriverter® BP-201 and EP-301

We have developed two new organic coagulants that clump and remove the organic substances responsible for reducing the quality of filtration. These coagulants can eliminate membrane-contaminating materials that conventional inorganic coagulants (such as poly-aluminum chloride) cannot, halving the amount of inorganic coagulant required and reducing the amount of sludge generated.

2. Slime control agent Kuriverter® IK-110

Conventional slime control agents are capable of sterilizing bacteria. In addition to this function, our new slime control agent is also capable of on-line removal of organic fouling substances on the membrane without damaging the membrane itself. The new agent is effective in treating a wide range of bacteria and makes it possible for activated carbon fillers to be used for slime control, thus keeping the membrane from deteriorating and reducing the frequency at which membranes require cleaning.

3. Scale inhibitors Kuriverter® N-195 and N-500

We have developed highly functional scale inhibitors that can effectively inhibit the formation and growth of scale on the RO membrane. They can prevent clogging of the membrane, which leads to reduced permeate water flow, and prevent the quality degradation of the permeated water.

Kuriverter® N-195 acts on silica-based scale and Kuriverter® N-500 inhibits calcium-based scale.

4. Other equipment and solutions

Kurita also offers the following equipment and solutions to meet the needs of our customers.

  1. Highly functional filtration equipment
    Our highly functional filtration equipment effectively eliminates contaminants attached to RO membranes, ensuring that pretreatment chemicals can work to maximum effect.
  2. Water treatment techniques for RO membrane-permeate water
    We can propose a variety of techniques and systems for utilizing waste water reclaimed with RO membrane processing as industrial cooling water, as well as systems for converting RO membrane-permeate water into ultra pure water.

4. Future Market Development

We will continue our efforts to develop useful products and services for our customers in the semiconductor industry, who are big users of RO membranes, and on overseas markets in Asia and the Middle East, where the demand for RO membrane-related products is expected to increase due to water shortages and the growing need to reduce environmental impact.