In Situ Performance of Granular Activated Carbon for Sampling Viruses and Bacteria from Wastewater: Toward Quantitative Passive Sampling for Wastewater-based Epidemiology

Expanding the WBE footprint to include low-resource settings where small, informal, and ad-hoc wastewater systems and high burdens of disease are co-located requires resource-efficient and adaptable methods. To that end, we deployed passive samplers made of granular activated carbon (GAC) into raw influent at a small wastewater treatment plant continuously over 90 days. Detections of SARS-CoV-2 RNA, respiratory syncytial virus RNA, and human adenovirus DNA on GAC passive samplers were coincident with regional clinical trends during a low-incidence period. GAC also recovered bacterial DNA, including mapA, a gene associated with Campylobacter jejuni. A set of antibiotic resistance genes – tetW, blaTEM, blaCTX – were also quantified from GAC passive samplers and did not show increased relative abundance over exposure durations up to 168 hours. Sequencing of 16S rRNA amplicons indicated the GAC samplers recovered bacterial families abundant in both wastewater and feces. Over 38 deployments up to 168 hours long, the average uptake rate decayed exponentially with exposure duration for 16S rRNA (R2 = 0.972), pepper mild mottle virus (R2 = 0.882), and human adenovirus (R2 = 0.585). GAC passive samplers may afford a resource-efficient approach to producing quantitative data for a wide variety of infectious agents relevant to WBE.