RoQuest™ Coagulant

Membrane-compatible coagulants to boost filter performance

Coagulation and Filtration

Our extensive autopsy library shows colloidal and particulate fouling are very frequent causes of fouling in reverse osmosis (RO) systems, resulting in reductions in performance efficiency and membrane element life.

Multi-media filtration is one of the most common and economical solutions for removing colloidal material from the feed stream of RO membrane systems. However, media filters alone are typically successful in removing only 30 to 50 per cent of feed water colloids.

While very significant improvements in performance can be achieved by dosing chemical coagulants upstream of the filter, many of these coagulants can have severe and permanent consequences for membrane performance if they pass through into the RO feedwater. 

Kurita offers a solution to this problem with a range of proprietary membrane-compatible coagulants that can dramatically boost filter performance – typically taking removal rates up to 95 to 99%.

RoQuest™ Coagulant Benefits

The use of RoQuest coagulants offers the following benefits to RO system operators:

Reductions in cleaning frequency

Improved energy efficiency

Improved membrane element life

Better production rates

Reductions in cartridge filter consumption

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Kurita’s membrane treatment biofilm control agent specifically designed with the unique ability to deeply penetrate and remove foulant from the surface while inhibiting future growth.

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RoClean™ Cleaners

Restore reverse osmosis (RO) membrane performance and extend system lifespan with RoClean membrane cleaners. Formulated to effectively remove scale, organic fouling, biofilm, and metal deposits, RoClean helps recover permeate flow, improve salt rejection, and reduce operating costs. Suitable for a wide range of industrial, municipal, food & beverage, and wastewater reuse applications.

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Tetsuya Teramoto

Tetsuya Teramoto

Managing Director, Kurita R&D Asia Pte. Ltd.

Mr. Tetsuya Teramoto has served as Managing Director of Kurita R&D Asia Pte. Ltd. since 2024. Since joining Kurita Water Industries in 2006, he has accumulated nearly 20 years of experience in technology strategy, research and development, and business innovation, including investments in startup companies.

Throughout his career, Mr. Teramoto has led development projects across Japan, China, and the United States. Since 2023, he has been based in Singapore, where he has focused on accelerating technology development aligned with ASEAN market needs, strengthening partnerships with startups, universities, and other ecosystem stakeholders, and driving the creation of emerging solutions that contribute to the Kurita Group’s growth.

Mr. Teramoto holds a Master’s degree in Biosystem Studies from the University of Tsukuba, Japan. Leveraging his expertise in both research and development and business strategy, he is committed to driving innovation that transforms technology into business value and sustainable growth opportunities.

Zackariya

Mohamad Zackariya

Managing Director, Kurita (Singapore) Pte. Ltd.

Mr. Mohamad Zackariya has served as Managing Director of Kurita (Singapore) Pte. Ltd. since April 2023, capping a distinguished career of more than 25 years with the company. A Singaporean national, he joined Kurita Singapore in 1998 as a Design Engineer in the Plant Division and progressed through a series of leadership roles, including Manager, General Manager, Director, and ultimately Managing Director. His extensive experience has played a key role in strengthening the company’s technical capabilities, customer partnerships, and business growth across the region.

Holding a Bachelor’s Degree in Mechanical Engineering from University of Moratuwa, Sri Lanka and a Post Graduate Diploma in Business Management from Singapore Institute of Management, Mr. Zackariya combines deep technical expertise with strong business leadership. He is committed to advancing Kurita’s mission of creating shared value through innovation, operational excellence, and sustainable water solutions that support customers and industries throughout Southeast Asia.

Masato Hirai

Masato Hirai

Chief Administration Officer, ASEAN Regional

Mr. Masato Hirai serves as ASEAN Regional Chief Administration Officer at Kurita, a role he has held since 2023. With more than 25 years of experience in corporate administration, financial planning, and business operations, he brings extensive expertise in supporting organizational growth, strengthening governance, and driving operational excellence across international business environments.

Mr. Hirai joined Kurita Group in 2021 and has held leadership positions in Japan, Malaysia, Thailand, and Indonesia. Throughout his career, he has been responsible for financial planning and analysis, business administration, and the management of cross-functional corporate operations. He has also supported overseas subsidiaries across Asia, Europe, and North America, contributing to the development of effective business practices and strong stakeholder relationships. Prior to joining Kurita, he held management and planning roles at several multinational manufacturing and chemical companies.

Known for his strategic vision and collaborative approach to leadership, Mr. Hirai is committed to strengthening organizational performance and creating long-term sustainable growth. Currently based in Indonesia, he leverages extensive international experience to support Kurita’s regional development and business transformation initiatives. He graduated from Hitotsubashi University, Japan, with a Bachelor of Social Sciences degree in 1999.

Toshiaki Nakai

Toshiaki Nakai

General Director, Kurita-GK Vietnam Co. Ltd.

Mr. Toshiaki Nakai serves as General Director of Kurita-GK Vietnam Co. Ltd., a position he has held since April 2026. With more than 20 years of experience at Kurita, he has developed extensive expertise in water treatment solutions, business development, and customer partnership management across a wide range of industrial sectors, including general manufacturing, oil refining, and steel production.

Since joining Kurita Water Industries Ltd. in 2004 as a Sales Engineer, Mr. Nakai has supported customers in optimizing water use, enhancing operational efficiency, and advancing sustainability initiatives. He later expanded his leadership responsibilities in Indonesia, serving as General Manager of PT. Kurita Indonesia from 2022 to 2025 and Senior General Manager from 2025 to 2026, where he contributed to the company’s growth and strengthened its market presence.

Mr. Nakai holds a Bachelor’s Degree in Agriculture from Kobe University, Japan, graduating in 2004.

Toshinori Maema

Toshinori Maema

President Director, P.T. Kurita Indonesia

Mr. Toshinori Maema has served as President Director of PT. Kurita Indonesia since 2025, bringing over 20 years of experience in sales, marketing, technical, and business leadership within the water treatment industry. Having worked across Asia, Europe, and North America, he offers a global perspective on customer engagement, organizational development, and sustainable business growth.

Since joining the Kurita Group in 2004, Mr. Maema has held leadership positions at various Kurita companies in China, Europe, Japan, and Avista Technologies in the United States, where he served as President & CEO from 2023 to 2025 to focus on global initiatives to expand the Kurita reverse osmosis chemicals business. With more than half of his career spent outside Japan, he has developed extensive experience in leading multicultural teams and driving business growth across diverse markets.

Mr. Maema holds a degree in Biochemistry from Aoyama Gakuin University and completed the Leadership on Change program at IESE Business School. Fluent in Japanese, English, and Chinese, with elementary proficiency in German, he is passionate about fostering collaboration across cultures. Outside of work, he enjoys a wide range of sports, including golf, baseball, soccer, and basketball.