Operational Constraints of Detecting SARS-CoV-2 on Passive Samplers using Electronegative Filters: A Kinetic and...

Area of Science:

• Environmental Science
• Virology
• Analytical Chemistry

Background:

• Wastewater surveillance is vital for monitoring SARS-CoV-2.
• Passive sampling is effective but SARS-CoV-2 RNA adsorption is poorly understood.
• Understanding adsorption is key to linking wastewater data to community infection levels.

Purpose of the Study:

• To evaluate the adsorption kinetics and equilibrium of SARS-CoV-2 RNA on passive sampling materials.
• To investigate the influence of wastewater characteristics, specifically total suspended solids (TSS), on adsorption.
• To provide recommendations for optimizing passive sampling methods in wastewater surveillance.

Main Methods:

• Batch-adsorption experiments were conducted using heat-inactivated SARS-CoV-2 (HI-SCV-2) and electronegative filters.
• Equilibrium isotherms were assessed across varying wastewater TSS concentrations (118, 265, and 497 mg L⁻¹).
• Adsorption kinetics were modeled using pseudo-first-order kinetics, and viral recovery was analyzed in relation to TSS.

Main Results:

• A maximum adsorption capacity (qmax) of 7 × 10³ GU cm⁻² was modeled.
• Surrogate SARS-CoV-2 RNA adsorption followed pseudo-first-order kinetics, reaching equilibrium within 24 hours.
• Both wastewater and eluate TSS were associated with adsorption equilibrium and viral recovery, indicating potential solids inhibition.

Conclusions:

• Passive sampling of SARS-CoV-2 RNA is influenced by adsorption characteristics and wastewater TSS.
• A deployment duration of 24-48 hours is recommended for passive sampling.
• Measuring eluate TSS is advised to assess potential solids inhibition and improve wastewater surveillance accuracy.