KMS Chongqing Institute of Green and Intelligent Technology, CAS
| Green process for supercritical water oxidation of sewage sludge with red mud as CO2absorbent | |
Chen, Hongzhen1,2,3 ; Wang, Guangwei1,2,3,4; Xu, Yuanjian1,3; Chen, Zhong1,3; Yin, Fengjun1,3
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| 2016 | |
| 摘要 | To mineralize CO2produced in situ and other acidic substances originating from organic components in sewage sludge, we developed a green SCWO system involving the treatment of sewage sludge with red mud as an alkaline absorbent. In this new system, two steps of mineralization were covered. Primary mineralization occurred inside the SCWO reaction vessels with part of CO2produced in situ. By this primary treatment, total inorganic carbon of the solid residue increased rapidly, predominantly in the form of calcite. Moreover, the S and P content increased by more than ten times compared with that of pure sludge. The pH of the drained water increased from 5.16 to about 7.7 with the addition of 2% red mud. The second mineralization step involved the exhausts cleaning reaction using red mud slurry. With 2.5 h of cleaning reactions at pressures of 0.1, 1, 3, and 5 MPa, approximately 4.49, 5.30, 6.06, and 7.52 g, respectively, of CO2per 100 g of red mud were bound in calcite. The high CO2absorption capacity was ascribed to the high pressure cleaning reaction, which was conveniently achieved in this SCWO system just by a simple adjustment of the back-pressure valve. With this green SCWO disposal, CO2level in the exhausts were cut to below 800 ppm (mg/L); SO2and nitrogen oxides (NO, NO2) diminished to below 15 ppm and 12 ppm, respectively. Due to the comparative stability of the solid residues obtained, they can easily be handled using conventional methods or recycled for a range of industrial applications including building materials, water treatment materials, special ceramics, or silicate cements. © 2016 Elsevier Ltd. All rights reserved. |
| DOI | 10.1016/j.jece.2016.06.013 |
| 发表期刊 | Journal of Environmental Chemical Engineering
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| 卷号 | 4期号:3页码:3065-3074 |
| 通讯作者 | Wang, Guangwei (wangguangwei@cigit.ac.cn) |
| 收录类别 | EI |
| 语种 | 英语 |
| EISSN | 22133437 |
