Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2022 Nov;12(11):288.
doi: 10.1007/s13205-022-03354-5. Epub 2022 Sep 21.

Acidithiobacillus sp. applied to sewage sludge bioleaching: perspectives for process optimization through the establishment of optimal operational parameters

Letícia P do Nascimento  1 , Jamile Gonçalves  1 , Iolanda C Duarte  1
Affiliations
Review

Acidithiobacillus sp. applied to sewage sludge bioleaching: perspectives for process optimization through the establishment of optimal operational parameters

Letícia P do Nascimento et al. 3 Biotech. 2022 Nov.

Abstract

Using Acidithiobacillus sp. during bioleaching assays is a well-known biological approach to solubilizing metals within sewage sludge. However, sludge dewatering has also been reported as a secondary treatment benefit. Based on a literature review, the present work provides perspectives regarding the enhancement of bioleaching outcomes on a laboratory scale by establishing optimal operational parameters. Data from different studies suggest that greater bioleaching efficiency may be achieved using a 10% (v/v) mixed inoculum of Acidithiobacillus thiooxidans and Acidithiobacillus ferrooxidans in a ratio of 4:1, supplemented with ferrous sulfate (FeSO4) and elemental sulfur (S0), and an initial system pH near 6.0. However, operational parameters must be established according to the type of sludge being treated due to differences in their compositions. Bioleaching duration is also an aspect that must be considered since treatments conducted for longer than 48 h increased the concentration of Extracellular Polymeric Substances (EPS), a characteristic associated with reducing dewaterability performance.

Keywords: Acidithiobacillus ferrooxidans; Acidithiobacillus thiooxidans; Dewatering; Extracellular polymeric substances.

PubMed Disclaimer

Conflict of interest statement

Conflict of interestOn behalf of all authors, the corresponding author states that there is no conflict of interest.

Figures

Fig. 1
Fig. 1
Methodological approach used to select articles for analysis
Fig. 2
Fig. 2
Research articles about bioleaching obtained from the search for keywords in Science Direct, Scopus, and Web of Science databases—Historical series of publications
Fig. 3
Fig. 3
Stages of wastewater and sewage sludge treatment, from water consumption until management—water consumption: urbanization process enhances water consumption and, consequently, the amount of wastewater generated; wastewater treatment: effluents are sent to Wastewater Treatment Plants (WWTP), and both liquid and solid phases are submitted adequately to specific treatment strategies; sludge generation: sludge is generated in several parts of a WWTP depending on the type of treatment implemented; sludge management: the generated sludge can be submitted to stabilization, thickening, dewatering, and another specific process before its disposal to reduce volume, water content and the presence of pathogens and toxic substances
Fig. 4
Fig. 4
Stratification of Extracellular Polymeric Substances (EPS) layers—Slime EPS (S-EPS): soluble and commonly available in the supernatant after sludge sedimentation; loosely bound EPS (LB-EPS): weakly bound to particles, does not provide well-established coverage; tightly bound EPS (TB-EPS): well-defined shape and very stable linked to the cell surface; and pellet: residual cell obtained after EPS extraction
See this image and copyright information in PMC

References

    1. Ambaye T, Vaccari M, Prasad S, Rtimi S. Preparation, characterization and application of biosurfactant in various industries: a critical review on progress, challenges, and perspectives. Environ Technol Innov. 2021;24:102090. doi: 10.1016/j.eti.2021.102090. - DOI
    1. Anjum M, Al-Makishah NH, Barakat MA. Wastewater sludge stabilization using pre-treatment methods. Process Saf Environ Prot. 2016;102:615–632. doi: 10.1016/J.PSEP.2016.05.022. - DOI
    1. Ban Y, Li L, Liu C, Yan Y, Gao J, Zhang J, Gao J. Enhancing sludge dewatering and heavy metal removal by bioleaching with Na2S2O3 as substrates. Water Sci Technol. 2018;78:1545–1555. doi: 10.2166/WST.2018.432. - DOI - PubMed
    1. Bertanza G, Canato M, Laera G, Tomei MC. Methodology for technical and economic assessment of advanced routes for sludge processing and disposal. Environ Sci Pollut Res Int. 2015;22:7190–7202. doi: 10.1007/S11356-014-3088-0. - DOI - PubMed
    1. Bosecker K. Bioleaching: metal solubilization by microorganisms. FEMS Microbiol Rev. 1997;20(3–4):591–604. doi: 10.1016/S0168-6445(97)00036-3. - DOI

LinkOut - more resources