Detection of SARS-CoV-2 and Other Viruses in Wastewater: Optimization and Automation of an Aluminum Hydroxide Adsorption-Precipitation Method for Virus Concentration

This study aimed to provide a low-cost technique for virus detection in wastewater by improving an aluminum hydroxide adsorption-precipitation method. The releasing efficiency of viruses trapped by the aluminum hydroxide precipitates was improved by adding ethylenediaminetetraacetic acid disodium salt (EDTA-2Na) to dissolve the precipitates at a Na(2)EDTA center dot 2H(2)O:AlCl3 molar ratio of 1.8-3.6. The recovery rates of the improved method for seven viruses, including SARS-CoV-2-abEN pseudovirus and six animal viruses, were 5.9-22.3% in tap water and 4.9-35.1% in wastewater. Rotavirus A (9.0-4.5 X 10(3) copies/mL), porcine circovirus type 2 (5.8-6.4 X 10(5) copies/mL), and porcine parvovirus (5.6-2.7 X 10(4) copies/mL) were detected in China's pig farm wastewater, while rotavirus A (2.0 X 10(3) copies/mL) was detected in hospital wastewater. SARS-CoV-2 was detected in hospital wastewater (8.4 X 10(2) to 1.4 X 10(4) copies/mL), sewage (6.4 X 10 to 2.3 X 10(3) copies/mL), and river water (6.6 X 10 to 9.3 X 10 copies/mL) in Nepal. The method was automized, with a rate of recovery of 4.8 +/- 1.4% at a virus concentration of 10(2) copies/mL. Thus, the established method could be used for wastewater-based epidemiology with sufficient sensitivity in coping with the COVID-19 epidemic and other virus epidemics.

Automated summary

This study aimed to provide a low-cost technique for virus detection in wastewater by improving an aluminum hydroxide adsorption-precipitation method. The method improved the recovery rates of viruses in tap water and wastewater by adding EDTA-2Na to dissolve the precipitates. The automized method showed sufficient sensitivity for wastewater-based epidemiology in coping with COVID-19 and other virus epidemics.