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.
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.
J Environ Manage. 2022 May 15;310:114758. doi: 10.1016/j.jenvman.2022.114758. Epub 2022 Mar 4.
Corn straw is rich in resources, and the preparation of biochar as the constructed wetland (CW) substrate is an effective measure to realize high-value resource utilization. The objective of this paper was to improve the treatment effect of CW on city tail water, the freeze-thaw cycles (FTCs) modification and chemical modification (KMnO, NaOH and HSO) of straw biochar and the utilization of modified straw biochar in CW were studied. The modification characteristics of straw biochar were discussed through scanning electron microscope, element determination, pore structure determination, X-ray diffraction analysis, Fourier transform infrared reflection analysis, CO adsorption and desorption experiment and application experiment of CW (no plants and plants). The results show that under the influence of strong oxidation of KMnO, the combination of KMnO and FTCs modification is easy to cause the destruction of biochar structure, and the content of carbon element is reduced. Except for the combined modification of NaOH and FTCs, other composite modifications have little effect on the crystal structure and functional groups of straw biochar. The adsorption capacity of CO by FTCs modified biochar increased by 20.4%, and the adsorption capacity of CO by HSO and FTCs composite modified biochar increased by 23.0%. The effect of HSO modification of straw biochar based on FTCs modification is obviously better than that of NaOH and KMnO. The research results are of great significance to improve the material structure of biochar and the purification effect of CW on city tail water.
秸秆资源丰富，将生物炭制备为人工湿地（CW）基质是实现高值化资源利用的有效措施。本研究旨在提高 CW 对城市尾水的处理效果，研究了秸秆生物炭的冻融循环（FTCs）改性和化学改性（KMnO、NaOH 和 HSO）以及改性秸秆生物炭在 CW 中的应用。通过扫描电子显微镜、元素测定、孔径结构测定、X 射线衍射分析、傅里叶变换红外反射分析、CO 吸附和解吸实验以及 CW（无植物和植物）应用实验探讨了秸秆生物炭的改性特征。结果表明，在 KMnO 强氧化作用的影响下，KMnO 与 FTCs 联合改性容易导致生物炭结构破坏，碳元素含量降低。除了 NaOH 和 FTCs 的联合改性外，其他复合改性对秸秆生物炭的晶体结构和官能团影响较小。FTCs 改性生物炭的 CO 吸附量增加了 20.4%，HSO 和 FTCs 复合改性生物炭的 CO 吸附量增加了 23.0%。基于 FTCs 改性的 HSO 改性秸秆生物炭的效果明显优于 NaOH 和 KMnO。研究结果对改善生物炭的材料结构和 CW 对城市尾水的净化效果具有重要意义。
