Controlled-release Hydrogel for Mitigating Sewer Environment


Based on controlled-release of biocide, this hydrogel technology converts hydrogen sulfide and ammonia gases in air into harmless and odorless products, which aims to address the malodor problem at the source by killing odor causing microbes and inhibiting odor generation and converting malodors through catalytic transformation.

  • Controlled-release Hydrogel for Mitigating Sewer Environment
Commercialisation opportunities
Technology licensing agreement
Problem addressed

Malodor is an important class of air pollution that has a serious threat to personal health and quality of life. Sewer is one of major sources of malodor in urban environment and is particularly difficult to be treated.

  • Effectively convert H2S and NH3 into harmless minerals, water and N2
  • Operates under high humidity (100 % R.H.) and dark conditions
  • Long and stable operating life under extreme operating conditions found in drainage system
Key impact
  • Inhibit microorganisms causing malodor in drainage and sewage systems
  • Work under aggressive environment in sewer and drainage system
  • Over 80% H2S suppression
  • Effective for at least 30 days
  • Drainage systems
  • Sewage treatment sites
  • Waste treatment and handling facilities
  • Landfills


  • US Patent 13/997795 16/175031
  • CNIPA Chinese Patent 201180063144.6
  • HK Patent : 13112633.3
The Hong Kong University of Science and Technology (HKUST)

The Hong Kong University of Science and Technology (HKUST) ( is a world-class research intensive university that focuses on science, technology and business as well as humanities and social science. HKUST offers an international campus, and a holistic and interdisciplinary pedagogy to nurture well-rounded graduates with global vision, a strong entrepreneurial spirit and innovative thinking. Over 80% of our research work were rated “Internationally excellent” or “world leading” in the Research Assessment Exercise 2020 of Hong Kong’s University Grants Committee. We were ranked 3rd in Times Higher Education’s Young University Rankings 2022, and our graduates were ranked 23rd worldwide and among the best from universities from Asia in Global University Employability Survey 2021.