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Facile Preparation of Internally Self-assembled Lipid Particles Stabilized by Carbon Nanotubes
Published on: February 19, 2016
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Carbon nanotubes accelerates the bio-induced vivianite formation
Zexuan He1, Jifei Chang1, Yujie Feng2
1Academy of Eco-Environmental Science, School of Environmental Science and Engineering, Tianjin University, No. 135 Yaguan Road, Jinnan District, Tianjin 300350, China.
The Science of the Total Environment
|July 5, 2022
Summary
Carbon nanotubes (CNTs) enhance vivianite production from wastewater sludge by 17% by promoting microbial electron transfer. Despite initial toxicity, CNTs stimulate bacteria to form protective biofilms, ultimately increasing phosphate recovery.
Area of Science:
- Environmental Science
- Microbiology
- Materials Science
Background:
- Vivianite, a phosphate resource, is found in wastewater sludge.
- Conductive materials like carbon nanotubes (CNTs) can enhance vivianite production by promoting extracellular electron transfer (EET) and biological iron reduction.
- The impact of CNTs on vivianite formation in wastewater treatment plants (WWTPs) is not well understood.
Purpose of the Study:
- To investigate the influence of CNTs on iron reduction, vivianite recovery, and biotoxicity in sludge.
- To determine the optimal conditions for CNTs to enhance vivianite production.
Main Methods:
- Addition of CNTs to sewage sludge.
- Monitoring of iron reduction and vivianite recovery.
- Analysis of CNTs' biotoxicity using SEM, CLSM, and AFM.
- Assessment of dissimilative iron-reducing bacteria (DIRB) viability and extracellular polymeric substances (EPS) production.
Main Results:
- Vivianite production increased by up to 17% with CNTs due to enhanced electron transfer.
- Initial Fe(III) reduction efficiency decreased by 81% due to CNTs damaging cell membranes.
- CNTs stimulated DIRB to produce EPS and form protective bio-flocs, increasing DIRB viability to 98% after 48 hours.
- Vivianite recovery increased to 44 ± 1% with 1000 mg/L CNTs, a 33% improvement.
Conclusions:
- CNTs can significantly enhance vivianite production and recovery from wastewater sludge.
- While CNTs exhibit initial biotoxicity, microbial adaptation leads to improved performance.
- Optimized use of CNTs offers a promising strategy for phosphate recovery from WWTPs.
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