التفاصيل البيبلوغرافية
| العنوان: |
Effects of pH-varying thermal modification on sewage sludge: A focus on releasing nitrogen- and phosphorus-containing substances. |
| المؤلفون: |
Liu, Rui1 (AUTHOR), Xu, Ying1,2 (AUTHOR) xuy@tongji.edu.cn, Cao, Jiachang1 (AUTHOR), Geng, Hui1 (AUTHOR), Chen, Renjie1 (AUTHOR), Liu, Haoyu1 (AUTHOR), Chen, Yongdong1 (AUTHOR), Yuan, Shijie1 (AUTHOR), Dai, Xiaohu1,2 (AUTHOR) daixiaohu@tongji.edu.cn |
| المصدر: |
Water Research. Jun2024, Vol. 257, pN.PAG-N.PAG. 1p. |
| مصطلحات موضوعية: |
*SEWAGE sludge, *MOLECULAR structure, *SOLID-liquid interfaces, *ELECTROSTATIC interaction, *CARBOXYL group |
| مستخلص: |
• The complex nature of sludge was dismantled by pH-varying thermal modification. • The release of N-containing substances (NCS) varied in a tick-like function. • Thermal protons exhibited a notable accumulative mutagenic effect on NCS release. • Release of P-containing substances exhibited a contrasting response to that of NCS. • The reaction sites of thermal H + and OH− for P-containing substances were different. Sewage sludge is promising for the recovery and utilisation of nutrient components, but its complex nature hinders the release of these components. The combination of pH and thermal modifications shows promise for the release of nutrient components from sludge. However, comprehensive studies on the full spectrum of pH levels and corresponding mechanisms of pH-varying thermal modification are lacking. In this study, the main nutrient components, physicochemical properties, molecular structure, and noncovalent interactions of sludge were comprehensively investigated through pH-varying thermal modification (within a pH range of 2.0 to 12.0 under the same thermal condition). The experimental results showed that the release of main organics, particularly nitrogen (N)-containing organics, was well-fitted, with a tick-like function (R 2: 0.74–0.96). The thermal protons exhibited a notable accumulative mutagenic effect on the N-containing organics release, while the thermal hydroxyl ions had a more direct effect, as revealed by the changes in multivalent metals and molecular structures with the protonation–deprotonation of carboxyl groups. The driving force for the release of N-containing organics was identified as the fluctuation of electrostatic interactions at the solid–liquid interface of the sludge. However, the release of phosphorus (P)-containing substances exhibited a contrasting response to that of N-containing substances with varying pH, likely because the reaction sites of thermal protons and thermal hydroxyl ions for P-containing substances were different. Moreover, high concentrations of thermal protons and hydroxyl ions collapsed the Lifshitz–van der Waals interactions of sludge, resulting in a decrease in viscoelasticity and binding strength. These propositions were further confirmed through statistical analyses of the main indicators of the main nutrient components, physicochemical properties, and noncovalent interactions of sludge. These findings can provide a basis for optimising characteristic-specific methods to recovery nutrient components (N/P) from sludge. [Display omitted] [ABSTRACT FROM AUTHOR] |
| قاعدة البيانات: |
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