Mitigating hydrogen sulfide emissions in urban drainage systems: Efficacy of a malodor-control hydrogel

Urban drainage systems are essential for effective stormwater and wastewater management, yet they often face challenges, including malodorous emissions and microbial contamination, primarily resulting from hydrogen sulfide (H₂S) production. This study aims to evaluate the efficacy of a novel malodor-control (MOC) hydrogel in mitigating H₂S concentrations and reducing microbial loads in urban drainage systems. Our objectives include: (1) assessing the hydrogel's impact on H₂S levels in both stormwater drains and sewer systems; (2) evaluating its bactericidal properties against odor-causing anaerobes; and (3) investigating its ecological implications on aquatic life. Field trials conducted in stormwater drains demonstrated that a 400 g dose of the MOC hydrogel can achieve a remarkable reduction in H₂S levels of 92 %, decreasing concentrations from an average of 4.14 ± 2.97 ppm to 0.32 ± 1.07 ppm (p < 0.0001) over 28 days of deployment and treating approximately 50,000 m³ of stormwater. Similarly, the hydrogel reduced H₂S concentrations in sewer systems by 95 %, from 107.32 ± 122.57 ppm to 5.00 ± 2.45 ppm (p < 0.0001). Furthermore, the hydrogel significantly decreased anaerobic bacterial counts by 71.2 ± 64.4 % (p = 0.038) in stormwater drains, contributing to enhanced water quality. The findings of this research highlight the hydrogel's potential as an innovative solution for suppressing H₂S generation in urban drainage systems. By addressing critical public health concerns and minimizing environmental impacts, this study lays the groundwork for sustainable urban water management strategies that enhance urban resilience against climate-related challenges.