The relationship between the characteristics of Biochar produced at different temperatures and its impact on the uptake of NO3 --N
Background: Nitrogen leaching from agricultural lands is a major threat to groundwater and surface waters. This study investigated the relationship between the characteristics of wheat-straw biochar produced at different temperatures and its impact on the uptake of NO3--N. Methods: Three types of...
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| Format: | Article |
| Language: | English |
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Kerman University of Medical Sciences
2018-05-01
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| Series: | Environmental Health Engineering and Management |
| Online Access: | http://ehemj.com/article-1-341-en.html |
| Summary: | Background: Nitrogen leaching from agricultural lands is a major threat to groundwater and surface
waters. This study investigated the relationship between the characteristics of wheat-straw biochar
produced at different temperatures and its impact on the uptake of NO3--N.
Methods: Three types of biochar were produced from wheat straw at three different pyrolysis
temperatures of 300, 400 and 500°C, and sampling was done 3 times for each biochar. Physical and
chemical characteristics of biochar were determined using a variety of methods including specific surface
with methylene blue adsorption method, and elemental content with elemental analyzer, and water
solubility with standard ASTM (D5029-28) method. Statistical analysis was performed using Freundlich
and Langmuir models. Nitrate concentration was measured using a UV-V spectrophotometer with a
wavelength of 500 nm.
Results: It was indicated that with an increase in biochar pyrolysis temperature from 300 to 500°C, the
hydrogen, oxygen and nitrogen in the biochar were significantly decreased (P < 0.05) while the carbon
content, surface area, density and water solubility in biochar (P < 0.05) were increased. The results also
showed that the maximum nitrate adsorptive capacity of the three types of biochar occurred at pH=6
and contact time of 120 minutes. With increasing the temperature of biochar preparation, the efficiency
of biochar nitrate adsorption increased significantly.
Conclusion: The present study shows that pyrolysis temperature greatly influences the biochar
chemical and physical characteristics, and subsequently nitrate adsorption ability of the biochars. The
wheat straw biochar, which is produced at a pyrolysis temperature of 500°C, has the highest adsorption
capacity for nitrate. |
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| ISSN: | 2423-3765 2423-4311 |