Efficiency of Nitrate Removal from Groundwater by Adsorption on Raw and Treated Bentonite
The objective of this study was to treat groundwaters with a high initial nitrate (NO<sub>3</sub><sup>−</sup>) content (125 mg/L, and 177 mg/L) by adsorption onto a local bentonite in its raw state (RB), treated with a ratio of H<sub>2</sub>SO<sub>4</sub&...
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| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-01-01
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| Series: | Nitrogen |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2504-3129/6/1/6 |
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| Summary: | The objective of this study was to treat groundwaters with a high initial nitrate (NO<sub>3</sub><sup>−</sup>) content (125 mg/L, and 177 mg/L) by adsorption onto a local bentonite in its raw state (RB), treated with a ratio of H<sub>2</sub>SO<sub>4</sub>/bentonite = 0.2 (B0.2), and another treated with a ratio of H<sub>2</sub>SO<sub>4</sub>/bentonite = 0.6 (B0.6). Non-linear modelling of the nitrate adsorption kinetics of two water samples showed the pseudo-first-order model was the best fit, confirming that nitrate retention on each adsorbent was due to chemisorption. The intra-particle diffusion curves were multi-linear, indicating that there are other mechanisms influencing nitrate ion adsorption on bentonite than intra-particle diffusion. The effectiveness of the adsorbents tested was in the following order: B0.6 > B0.2 > RB. This finding demonstrates that acid activation of the clay improves its characteristics. The optimal adsorbent dose was found to be 1 g/L after changing the bentonite dose from 0.1 to 4 g/L. The pH of the treatment affects nitrate removal rates. The greatest results are achieved at pH levels close to 6. It also appears that the treatment was more effective for water with low initial nitrate levels. |
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| ISSN: | 2504-3129 |