PDF
Full
Outline
The reed biochar was chemically modified using hydrochloric acid, dicyandiamide, and magnesium chloride as activators. This study investigated the effects of varying pH values, addition amounts, and initial solution concentrations on the nitrate nitrogen adsorption capacity of four types of biochar. Additionally, the adsorption kinetics and thermodynamic characteristics of the biochars for nitrate nitrogen removal were analyzed. When reed straw is pre-carbonized at 500℃ for 2hours and subsequently activated with modified materials at 700℃ for 2hours, the resultant dicyandiamide-modified biochar (DBC) exhibits the best adsorption performance, achieving a removal efficiency of 75.5%. Compared to unmodified biochar (BC), the surface morphology of the modified biochars becomes more concave, with denser pores, increased functional groups, and a specific surface area enhanced by 7 to 10 times. When the potassium nitrate concentration is 500mg/L, the optimal dosages are 1g for BC, DBC, and magnesium chloride-modified biochar (MBC), and 0.8g for hydrochloric acid-modified biochar (HBC). The nitrate nitrogen adsorption performance of DBC is favorable in a slightly alkaline environment, with the highest adsorption capacity observed at a pH of 9. The nitrate nitrogen adsorption behavior of all four biochars aligns well with the pseudo-second-order kinetic model, and their isothermal adsorption curves fit the Langmuir equation, suggesting predominantly monomolecular layer adsorption. Overall, DBC demonstrates excellent nitrate nitrogen adsorption performance and offers a promising solution for mitigating nitrate pollution in aquatic environments.
PDF
50
22
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |
关闭全屏
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62199257
qkjq@cast.org.cn
Copyright © 2025 China Association for Science and Technology. All rights reserved. For all open access content, the relevant licensing terms apply.
Sponsored by the Office of the Leading Group for Cybersecurity and Informatization of CAST, and supported by Science and Technology Review Publishing House
