A controlled-release gel, hydrogel that designed to reduce and inhibit the sulfate-reducing bacteria is studied and assessed to its operational performance on H₂S suppression at sewer, box culvert and outlet to costal area in Hong Kong, also its effect on water quality.

Three locations of drainage with malodour problem are selected by Hong Kong Drainage Service Department (DSD) for two years-long field study are installed with industrial use H₂S detectors to record the H₂S concentration for analysis, water samples are also collected every inspection for comprehensive water quality monitoring. For the two years-long field study, more than eight cycles of test constituted with control period (without deploying hydrogel) and test period (deploying hydrogel) have been conducted from 2017 t...[ Read more ]

A controlled-release gel, hydrogel that designed to reduce and inhibit the sulfate-reducing bacteria is studied and assessed to its operational performance on H₂S suppression at sewer, box culvert and outlet to costal area in Hong Kong, also its effect on water quality.

Three locations of drainage with malodour problem are selected by Hong Kong Drainage Service Department (DSD) for two years-long field study are installed with industrial use H₂S detectors to record the H₂S concentration for analysis, water samples are also collected every inspection for comprehensive water quality monitoring. For the two years-long field study, more than eight cycles of test constituted with control period (without deploying hydrogel) and test period (deploying hydrogel) have been conducted from 2017 to 2019. The overall % reduction of H₂S in sewer, box culvert and outlet to costal area are all achieving about 99%, the H₂S level is suppressed from an overall average 4 ppm to under 1 ppm over 21 days. These results show a promising H₂S suppression in different drainage systems by decreasing the anaerobic bacteria population about 85% while keeping the water quality in range of statutory standard.