Enhanced in situ Pb(II) passivation by biotransformation into chloropyromorphite during sludge composting
| Autor: | Hanpeng Liao, Xinggui Yang, Zi-Qiang Zhao, Zhi Chen, Ruizhi Xing, Shungui Zhou |
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| Rok vydání: | 2020 |
| Předmět: |
Environmental Engineering
Passivation Health Toxicology and Mutagenesis 0211 other engineering and technologies 02 engineering and technology 010501 environmental sciences engineering.material 01 natural sciences Phosphates Metal Soil Biotransformation Metals Heavy Environmental Chemistry Waste Management and Disposal 0105 earth and related environmental sciences 021110 strategic defence & security studies Minerals biology Sewage Chemistry Compost Thermophile Composting Biosorption Thermus thermophilus biology.organism_classification Pollution Lead Environmental chemistry visual_art visual_art.visual_art_medium engineering Biomineralization |
| Zdroj: | Journal of hazardous materials. 408 |
| ISSN: | 1873-3336 |
| Popis: | Composting is an effective technology for the disposal and utilization of solid biowastes. However, conventional composting is inefficient for the passivation of heavy metals in solid biowastes, thus limiting the applications of compost derived from solid biowaste. Here, a thermophilic biomineralization strategy was proposed and demonstrated during sludge composting for in situ heavy metals passivation via thermophiles inoculation. It was found that Thermus thermophilus could promote the transformation of Pb(II) into the most stable chloropyromorphite [Pb5(PO4)3Cl, Ksp = 10-84.4] during composting. After 40 days of composting with T. thermophilus FAFU013, the most insoluble residual fractions of Pb increased by 16.0% (from 76.5% to 92.5%), which was approximately 3 times higher than that of the uninoculated control. The DTPA-extractable Pb decreased to 11.5%, which was 14.4% less compared with the uninoculated control, indicating a significant Pb passivation by inoculation of T. thermophilus FAFU013. A series of batch experiments revealed that Pb(II) could be rapidly accumulated by selective biosorption and gradually transformed into chloropyromorphite through the biomineralization of T. thermophilus FAFU013. This study provides new insight into the mechanism of heavy metal passivation during composting and the problem associated with the disposal of Pb-contaminated solid biowastes through the biomineralization of thermophiles. |
| Databáze: | OpenAIRE |
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