Effect of ferrous iron loading on dewaterability, heavy metal removal and bacterial community of digested sludge by Acidithiobacillus ferrooxidans

Guiqin Cai; Majid Ebrahimi; Guanyu Zheng; Anna H Kaksonen; Christina Morris; Ian M O'Hara; Zhanying Zhang

doi:10.1016/j.jenvman.2021.113114

Effect of ferrous iron loading on dewaterability, heavy metal removal and bacterial community of digested sludge by Acidithiobacillus ferrooxidans

J Environ Manage. 2021 Oct 1:295:113114. doi: 10.1016/j.jenvman.2021.113114. Epub 2021 Jun 23.

Authors

Guiqin Cai¹, Majid Ebrahimi¹, Guanyu Zheng², Anna H Kaksonen³, Christina Morris³, Ian M O'Hara⁴, Zhanying Zhang⁵

Affiliations

¹ Centre for Agriculture and the Bioeconomy, Faculty of Science, Queensland University of Technology, Brisbane, QLD 4000, Australia; School of Mechanical, Medical and Process Engineering, Faculty of Engineering, Queensland University of Technology, Brisbane, QLD 4000, Australia.
² College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, Jiangsu, China.
³ Commonwealth Scientific and Industrial Research Organisation, Land and Water, Wembley, WA 6913, Australia.
⁴ Centre for Agriculture and the Bioeconomy, Faculty of Science, Queensland University of Technology, Brisbane, QLD 4000, Australia; School of Mechanical, Medical and Process Engineering, Faculty of Engineering, Queensland University of Technology, Brisbane, QLD 4000, Australia; ARC Centre of Excellence in Synthetic Biology, Queensland University of Technology, QLD 4000, Australia.
⁵ Centre for Agriculture and the Bioeconomy, Faculty of Science, Queensland University of Technology, Brisbane, QLD 4000, Australia; School of Mechanical, Medical and Process Engineering, Faculty of Engineering, Queensland University of Technology, Brisbane, QLD 4000, Australia; ARC Centre of Excellence in Synthetic Biology, Queensland University of Technology, QLD 4000, Australia. Electronic address: jan.zhang@qut.edu.au.

PMID: 34171779
DOI: 10.1016/j.jenvman.2021.113114

Abstract

Acidithiobacillus ferrooxidans ILS-2 was adapted in digested sludge and used to treat sludge for dewaterability improvement. Results showed that increasing ferrous iron loading increased sludge dewaterability, but the inoculation of the bioleaching strain had little effect on sludge dewaterability compared to controls without the strain. The total extracellular polymeric substances (EPS) contents of sludges with and without bioleaching treatment were similar except for bioleaching treatment at 10% ferrous iron loading (on sludge total solids) where total EPS was higher with bioleaching treatment. However, bioleaching treatment for 48 h had a notable effect on removal of heavy metals, such as Mn, Ni and Zn, especially at the high loadings of ferrous iron. In the presence of A. ferrooxidans, the removal of Ni, Mn and Zn reached 93%, 88% and 80%, respectively, at a ferrous iron loading of 21%. The sequencing of 16S rRNA genes indicated that increasing ferrous iron loadings to 15% and 21% increased the relative abundance of Acidithiobacillus, Acidocella (with A. ferrooxidans) and Carboxylicivirga (without A. ferrooxidans) but decreased the abundance of Pseudomonas and Acinetobacter after 48 h treatment. This study enhanced the understanding of the correlations between bioleaching treatment of digested sludge, sludge dewaterability, heavy metal removal and bacterial communities.

Keywords: Acidithiobacillus ferrooxidans; Bacterial community; Dewaterability; Heavy metal.

MeSH terms

Acidithiobacillus*
Hydrogen-Ion Concentration
Iron
Metals, Heavy*
RNA, Ribosomal, 16S / genetics
Sewage

Substances

Metals, Heavy
RNA, Ribosomal, 16S
Sewage
Iron

Supplementary concepts

Acidithiobacillus ferrooxidans