State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Jingyue Street 2555, Changchun 130017, China; Heilongjiang Province Key Laboratory of Geographical Environment Monitoring and Spatial Information Service in Cold Regions, Heilongjiang Province Collaborative Innovation Center of Cold Region Ecological Safety, School of Geographical Sciences, Harbin Normal University, Harbin 150025, China.
State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Jingyue Street 2555, Changchun 130017, China.
Ecotoxicol Environ Saf. 2022 Jun 15;238:113597. doi: 10.1016/j.ecoenv.2022.113597. Epub 2022 May 6.
The pollution of corn straw to the environment had attracted much attention. The preparation and alkali modification of corn straw biochar as the constructed wetland (CW) substrate was conducive to solving the environment pollution caused by straw and improving the purification effect of CW. The NaOH modification mechanism of corn straw biochar was analyzed by measuring the surface morphology, element content, specific surface area (SSA), pore volume, crystal structure, surface functional groups and CO adsorption. Biochar prepared under relatively optimal NaOH-modified conditions was used as the vertical flow CW substrate to treat city tail water. The results showed that controlling the modification condition of NaOH (< 1.0 mol·L, ≤ 24 h) was conducive to prevent the biochar structure destruction and C element reduction. The SSA and pore volume of NaOH (0.1 mol·L) modified biochar are 360 m·g and 0.109 cm·g, respectively. The biochar adsorption for CO conformed to the Langmuir and Freundlich isothermal adsorption theoretical model (R > 0.9). The maximum adsorption capacity of CO by modified biochar with NaOH (0.1 mol·L) was 64.516 cm·g and increased by 10.3%. The city tail water treated by CW with plants showed that the removal rates of ammonia nitrogen, total nitrogen and nitrate nitrogen reached about 90%. The research results improved the utilization value of straw, realized straw carbon sequestration and promoted the progress of CW technology.
玉米秸秆对环境的污染引起了广泛关注。玉米秸秆生物炭的制备和堿改性作为人工湿地（CW）的基质有利于解决秸秆造成的环境污染，提高 CW 的净化效果。通过测量表面形貌、元素含量、比表面积（SSA）、孔体积、晶体结构、表面官能团和 CO 吸附，分析了玉米秸秆生物炭的堿改性机理。以相对最佳 NaOH 改性条件下制备的生物炭作为垂直流 CW 基质处理城市尾水。结果表明，控制 NaOH 改性条件（<1.0 mol·L，≤24 h）有利于防止生物炭结构破坏和 C 元素减少。NaOH（0.1 mol·L）改性生物炭的 SSA 和孔体积分别为 360 m·g 和 0.109 cm·g。生物炭对 CO 的吸附符合 Langmuir 和 Freundlich 等温吸附理论模型（R>0.9）。NaOH（0.1 mol·L）改性生物炭对 CO 的最大吸附容量为 64.516 cm·g，增加了 10.3%。有植物的 CW 处理城市尾水后，氨氮、总氮和硝酸盐氮的去除率均达到 90%左右。研究结果提高了秸秆的利用价值，实现了秸秆的碳封存，促进了 CW 技术的发展。
