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

Abstract

In developing an effective monitoring program for the wastewater surveillance of SARS-CoV-2 ribonucleic acid (RNA), the importance of sampling methodology is paramount. Passive sampling has been shown to be an effective tool to detect SARS-CoV-2 RNA in wastewater. However, the adsorption characteristics of SARS-CoV-2 RNA on passive sampling material are not well-understood, which further obscures the relationship between wastewater surveillance and community infection. In this work, adsorption kinetics and equilibrium characteristics were evaluated using batch-adsorption experiments for heat-inactivated SARS-CoV-2 (HI-SCV-2) adsorption to electronegative filters. Equilibrium isotherms were assessed or a range of total suspended solids (TSS) concentrations (118, 265, and 497 mg L –1 ) in wastewater, and a modeled q max of 7 × 10 3 GU cm –2 was found. Surrogate adsorption kinetics followed a pseudo-first-order model in wastewater with maximum concentrations achieved within 24 h. In both field and isotherm experiments, equilibrium behavior and viral recovery were found to be associated with wastewater and eluate TSS. On the basis of the results of this study, we recommend a standard deployment duration of 24–48 h and the inclusion of eluate TSS measurement to assess the likelihood of solids inhibition during analysis.

Adsorption of Respiratory Syncytial Virus, Rhinovirus, SARS-CoV-2, and F+ Bacteriophage MS2 RNA onto Wastewater Solids from Raw Wastewater

“…Researchers have also examined the equilibrium and kinetic adsorption of SARS-CoV-2 RNA onto passive samplers designed for wastewater surveillance. 21 In our review of the previous work described above, we noted the lack of laboratory partitioning and/or distribution data on key respiratory viruses in wastewater, including SARS-CoV-2, RV, and RSV, which have been shown to be present in wastewater matrices and correlate to community disease occurrence. 22,23 In addition, we noted that the experiments typically did not include temperature as an experimental factor and that laboratory and field experiments were rarely coupled.…”

“…Partition coefficients (reported as K p in the paper) were 3.7 × 10 4 and 4.0 × 10 4 mL·g –1 in primary and secondary sludge, respectively. Researchers have also examined the equilibrium and kinetic adsorption of SARS-CoV-2 RNA onto passive samplers designed for wastewater surveillance …”

Looking Forward: The Role of Academic Researchers in Building Sustainable Wastewater Surveillance Programs

“…Various research teams have led efforts to develop passive sampling techniques, such as the Moore swab, for economical sampling of wastewater with superior performance to grab sampling. 71 – 73 In addition, researchers have also initiated efforts to develop molecular testing techniques that do not require expensive quantitative polymerase chain reaction (qPCR) equipment, such as loop-mediated isothermal amplification, 74 and have coupled these with passive samplers and electronegative membranes to allow rapid wastewater testing. 37 , 75 Researchers have also proposed paper-based testing devices and biosensors as future analytical platforms for near real-time surveillance of infectious agents in wastewater, although as of yet no proof of concept has been published.…”

Effectiveness of passive sampling for the detection and genetic characterization of human viruses in wastewater

“…5,7,19,47 High levels of suspended solids in wastewater may affect the adsorption of viruses to the electronegative membranes. Hayes and coworkers 49 demonstrated that adsorption of the virus to the sampling material is highly dependent of the characteristics of the water. Retention of solids can improve RNA recovery but and excessive retention can inhibit de RNA extraction process.…”