Reuse of nitric acid in the oxidative pretreatment step for preparation of humic acids from low rank coal of Mukah, Sarawak
Nitric acid is an effective material for production of humic acids. Nevertheless, it is an expensive item that renders the process unfavorable industrially. Study indicated that there was a possibility to reuse the nitric acid for oxidation however the resulting structures of humic acids was not stu...
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| Format: | Article |
| Language: | English |
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SciELO Publishing
2007
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| Online Access: | http://ir.unimas.my/id/eprint/7428/ http://ir.unimas.my/id/eprint/7428/1/Sim.pdf |
| _version_ | 1848836127763464192 |
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| author | Sim Siong, Fong Lau, Seng Haslinda, Mat |
| author_facet | Sim Siong, Fong Lau, Seng Haslinda, Mat |
| author_sort | Sim Siong, Fong |
| building | UNIMAS Institutional Repository |
| collection | Online Access |
| description | Nitric acid is an effective material for production of humic acids. Nevertheless, it is an expensive item that renders the process unfavorable industrially. Study indicated that there was a possibility to reuse the nitric acid for oxidation however the resulting structures of humic acids was not studied. Therefore, the objective of this study was to investigate the chemical and spectroscopic properties of nitrohumic acids prepared with reused nitric acid. The coal sample was oxidized with 5%, 10% and 15% of nitric acid and subjected to extraction for nitrohumic acids. Concentration of nitric acid with the most yields was reemployed for another 2 cycles of oxidation. The chemical and spectroscopic properties of nitrohumic acids were evaluated. The results indicated that oxidation process generally improved the acidic functional properties of the nitrohumic acids with 10% nitric acid producing the most promising yield. The nitric acid was reused for extraction and the percentage yield remained good at an average of 78%. Structurally, the nitrohumic acids produced with the reused nitric acid demonstrated larger molecular size and fewer acidic functional groups suggesting lesser extent of structure fractionation. |
| first_indexed | 2025-11-15T06:18:50Z |
| format | Article |
| id | unimas-7428 |
| institution | Universiti Malaysia Sarawak |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-15T06:18:50Z |
| publishDate | 2007 |
| publisher | SciELO Publishing |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | unimas-74282021-07-12T15:35:23Z http://ir.unimas.my/id/eprint/7428/ Reuse of nitric acid in the oxidative pretreatment step for preparation of humic acids from low rank coal of Mukah, Sarawak Sim Siong, Fong Lau, Seng Haslinda, Mat S Agriculture (General) TP Chemical technology Nitric acid is an effective material for production of humic acids. Nevertheless, it is an expensive item that renders the process unfavorable industrially. Study indicated that there was a possibility to reuse the nitric acid for oxidation however the resulting structures of humic acids was not studied. Therefore, the objective of this study was to investigate the chemical and spectroscopic properties of nitrohumic acids prepared with reused nitric acid. The coal sample was oxidized with 5%, 10% and 15% of nitric acid and subjected to extraction for nitrohumic acids. Concentration of nitric acid with the most yields was reemployed for another 2 cycles of oxidation. The chemical and spectroscopic properties of nitrohumic acids were evaluated. The results indicated that oxidation process generally improved the acidic functional properties of the nitrohumic acids with 10% nitric acid producing the most promising yield. The nitric acid was reused for extraction and the percentage yield remained good at an average of 78%. Structurally, the nitrohumic acids produced with the reused nitric acid demonstrated larger molecular size and fewer acidic functional groups suggesting lesser extent of structure fractionation. SciELO Publishing 2007 Article PeerReviewed text en http://ir.unimas.my/id/eprint/7428/1/Sim.pdf Sim Siong, Fong and Lau, Seng and Haslinda, Mat (2007) Reuse of nitric acid in the oxidative pretreatment step for preparation of humic acids from low rank coal of Mukah, Sarawak. Journal of the Brazilian Chemical Society, 18 (1). pp. 41-46. ISSN 0103-5053 http://www.scielo.br/scielo.php?pid=S0103-50532007000100004&script=sci_arttext doi.org/10.1590/S0103-50532007000100004 |
| spellingShingle | S Agriculture (General) TP Chemical technology Sim Siong, Fong Lau, Seng Haslinda, Mat Reuse of nitric acid in the oxidative pretreatment step for preparation of humic acids from low rank coal of Mukah, Sarawak |
| title | Reuse of nitric acid in the oxidative pretreatment step for preparation of humic acids from low rank coal of Mukah, Sarawak |
| title_full | Reuse of nitric acid in the oxidative pretreatment step for preparation of humic acids from low rank coal of Mukah, Sarawak |
| title_fullStr | Reuse of nitric acid in the oxidative pretreatment step for preparation of humic acids from low rank coal of Mukah, Sarawak |
| title_full_unstemmed | Reuse of nitric acid in the oxidative pretreatment step for preparation of humic acids from low rank coal of Mukah, Sarawak |
| title_short | Reuse of nitric acid in the oxidative pretreatment step for preparation of humic acids from low rank coal of Mukah, Sarawak |
| title_sort | reuse of nitric acid in the oxidative pretreatment step for preparation of humic acids from low rank coal of mukah, sarawak |
| topic | S Agriculture (General) TP Chemical technology |
| url | http://ir.unimas.my/id/eprint/7428/ http://ir.unimas.my/id/eprint/7428/ http://ir.unimas.my/id/eprint/7428/ http://ir.unimas.my/id/eprint/7428/1/Sim.pdf |