Document Type : Original Article
Authors
1
Department of Water Engineering, Faculty of Agricultural Engineering, Sari Agricultural Sciences and Natural Resources University, Sari, Iran
2
Associate Professor. Department of Water Engineering. Sari Agricultural Sciences and Natural Resources University
3
Department of Soil Science, Faculty of Crop Sciences, Sari Agricultural Sciences and Natural Resources University, Sari, Iran.
4
Department of Civil and Environmental Engineering, Faculty of Engineering, The University of the West Indies, St. Augustine Campus, St Augustine, Trinidad and Tobago.
Abstract
Discharge and disposal of wastewater containing high nitrate levels contribute to its increase in groundwater and water resources, posing adverse effects on the environment and human health. An experiment was conducted at laboratory water quality, Sari Agricultural Sciences and Natural Resources University, to investigate the impact of ultrasonic waves on nitrate removal and the absorption properties of rice straw biochar absorbents. Various treatments were applied, including ultrasound alone (U), biochar absorbent (B), biochar absorbent with ultrasound (BU), iron-coated biochar absorbent (BF), iron-coated biochar absorbent with ultrasound (BFU), zinc cation-coated biochar absorbent (BZ), and ultrasound with rice straw biochar coated with zinc cations (BZU). Results showed that ultrasonic waves effectively removed nitrates from the aqueous solution and enhanced the nitrate absorption process by the absorbent. In the iron and zinc-coated biochar absorbents, ultrasonication increased the optimal pH of the nitrate solution. The biochar and zinc-coated biochar absorbents exhibited a reduction in the optimal absorbent dose, and the optimal initial nitrate concentration in zinc-coated biochar increased from 80 ppm to 150 ppm. Overall, a 27% reduction in nitrate concentration was observed in the solution. Considering the results, a combined use of ultrasonication is recommended for a more efficient decomposition of pollutants.
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