Detection of SARS-CoV-2 and Other Viruses in Wastewater: Optimization and Automation of an Aluminum Hydroxide Adsorption–Precipitation Method for Virus Concentration
Lina Yu, Zhe Tian, Dev Raj Joshi, Lin Yuan, Reshma Tuladhar, Yu Zhang, Min Yang
Abstract
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 Na2EDTA·2H2O: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 × 103 copies/mL), porcine circovirus type 2 (5.8–6.4 × 105 copies/mL), and porcine parvovirus (5.6–2.7 × 104 copies/mL) were detected in China’s pig farm wastewater, while rotavirus A (2.0 × 103 copies/mL) was detected in hospital wastewater. SARS-CoV-2 was detected in hospital wastewater (8.4 × 102 to 1.4 × 104 copies/mL), sewage (6.4 × 10 to 2.3 × 103 copies/mL), and river water (6.6 × 10 to 9.3 × 10 copies/mL) in Nepal. The method was automized, with a rate of recovery of 4.8 ± 1.4% at a virus concentration of 102 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.