Interactive removal of bacterial and viral particles during transport through low-cost filtering materials

Xijuan Chen; Liqiong Yang; Junjie Guo; Shuang Xu; Junzhen Di; Jie Zhuang

doi:10.3389/fmicb.2022.970338

Interactive removal of bacterial and viral particles during transport through low-cost filtering materials

Front Microbiol. 2022 Aug 4:13:970338. doi: 10.3389/fmicb.2022.970338. eCollection 2022.

Authors

Xijuan Chen¹, Liqiong Yang¹, Junjie Guo², Shuang Xu³, Junzhen Di², Jie Zhuang⁴

Affiliations

¹ Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China.
² School of Civil Engineering, Liaoning Technical University, Fuxin, China.
³ College of Land and Environment, Shenyang Agricultural University, Shenyang, China.
⁴ Department of Biosystems Engineering and Soil Science, Center for Environmental Biotechnology, Institute for a Secure and Sustainable Environment, The University of Tennessee, Knoxville, TN, United States.

Abstract

Pathogen filtration is critically important for water sanitation. However, it is a big challenge to balance removal efficiency and filtering material cost. In this study, we quantified the removal processes of a bacterial strain Escherichia coli 652T7 and a model bacteriophage MS2 (ATCC 15597-B1) during their transport through columns containing iron filings (IF), calcined magnesite (CM), natural ore limestone (OL) or corn stalk biochar (BC) under saturated flow conditions. Experimental results showed that 99.98, 79.55, 63.79, and 62.59% of injected E. coli 652T7 and 98.78, 92.26, 68.79, and 69.82% of injected MS2 were removed by IF, CM, OL, and BC, respectively. The differences in removal percentage were attributed to the disparities of the microorganisms and filtering materials in surface function groups, surface charges, and surface morphology. Transport modeling with advection-dispersion equation (ADE) and interaction energy calculation with extended Derjaguin, Landau, Verwey, and Overbeek (XDLVO) model indicated that E. coli 652T7 and MS2 were mostly removed via irreversible attachment. In IF columns, E. coli 652T7 promoted the transport of MS2 but not vice versa. In CM columns, MS2 facilitated the transport of E. coli 652T7 and vice versa at a less extent. Such changes were a combined result of attachment site competition, steric effect, and mechanical straining. We found that the sum of the removal percentages of the two microorganisms in their respective transport experiments were similar to those calculated from their co-transport experiments. This result suggests that the removals were mainly limited by the attachment sites in the filtering materials.

Keywords: attachment; calcined magnesite; co-transport; iron filings; surface sites competition.