Efficient and synergistic treatment of selenium (IV)-contaminated wastewater and mercury (II)-contaminated soil by anaerobic granular sludge : Performance and mechanisms

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Wastewater containing selenium (Se) and soil contaminated by mercury (Hg) are two environmental problems, but they are rarely considered for synergistic treatment. In this work, anaerobic granular sludge (AnGS) was used to address both of the aforementioned issues simultaneously. The performance and mechanisms of Se(IV) removal from wastewater and Hg(II) immobilization in soil were investigated using various technologies. The results of the reactor operation indicated that the AnGS efficiently removed Se from wastewater, with a removal rate of 99.94 ± 0.05%. The microbial communities in the AnGS could rapidly reduce Se(IV) to Se0 nanoparticles (SeNPs). However, the AnGS lost the ability to reduce Se(IV) once the Se0 content reached the saturation value of 5.68 g Se/L. The excess sludge of Se0-rich AnGS was applied to remediate soil contaminated with Hg(II). The Se0-rich AnGS largely decreased the percentage of soil Hg in the mobile, extractable phase, with up to 99.1 ± 0.3% immobilization. Soil Hg(II) and Hg0 can react with Se (-II) and Se0, respectively, to form HgSe. The formation of inert HgSe was an important pathway for immobilizing Hg. Subsequently, the pot experiments indicated that soil remediation using Se0-rich AnGS significantly decreased the Hg content in pea plants. Especially, the content of Hg decreased from 555 ± 100 to 24 ± 3 μg/kg in roots after remediation. In summary, AnGS is an efficient and cost-effective material for synergistically treating Se-contaminated wastewater and Hg-contaminated soil.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:350

Enthalten in:

Chemosphere - 350(2024) vom: 24. Jan., Seite 141038

Sprache:

Englisch

Beteiligte Personen:

He, Zhanfei [VerfasserIn]
Shen, Jiaquan [VerfasserIn]
Zhao, Yuanhai [VerfasserIn]
Ru, Yulong [VerfasserIn]
Zhang, Daoyong [VerfasserIn]
Pan, Xiangliang [VerfasserIn]

Links:

Volltext

Themen:

Biological wastewater treatment
FXS1BY2PGL
H6241UJ22B
Heavy metals
Journal Article
Mercury
Microbial selenium reduction
Se(0) nanoparticles (SeNPs)
Selenium
Sewage
Soil
Soil remediation
Wastewater

Anmerkungen:

Date Completed 29.01.2024

Date Revised 29.01.2024

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.chemosphere.2023.141038

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM366385801