Physicochemical modification of corn straw biochar to improve performance and its application of constructed wetland substrate to treat city tail water

Hanxi Wang; Haowen Teng; Xinyu Wang; Jianling Xu; Lianxi Sheng

doi:10.1016/j.jenvman.2022.114758

Physicochemical modification of corn straw biochar to improve performance and its application of constructed wetland substrate to treat city tail water

J Environ Manage. 2022 May 15:310:114758. doi: 10.1016/j.jenvman.2022.114758. Epub 2022 Mar 4.

Authors

Hanxi Wang¹, Haowen Teng², Xinyu Wang³, Jianling Xu⁴, Lianxi Sheng⁵

Affiliations

¹ 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.
² 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.
³ State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Jingyue Street 2555, Changchun, 130017, China.
⁴ State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Jingyue Street 2555, Changchun, 130017, China; Key Laboratory of Vegetation Ecology of Ministry of Education, Institute of Grassland Science, Northeast Normal University, Changchun, 130024, Jilin, China; Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, China. Electronic address: xujl449@nenu.edu.cn.
⁵ State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Jingyue Street 2555, Changchun, 130017, China; Key Laboratory of Vegetation Ecology of Ministry of Education, Institute of Grassland Science, Northeast Normal University, Changchun, 130024, Jilin, China. Electronic address: shenglx@nenu.edu.cn.

PMID: 35255381
DOI: 10.1016/j.jenvman.2022.114758

Abstract

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 (KMnO₄, NaOH and H₂SO₄) 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, CO₂ adsorption and desorption experiment and application experiment of CW (no plants and plants). The results show that under the influence of strong oxidation of KMnO₄, the combination of KMnO₄ 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 CO₂ by FTCs modified biochar increased by 20.4%, and the adsorption capacity of CO₂ by H₂SO₄ and FTCs composite modified biochar increased by 23.0%. The effect of H₂SO₄ modification of straw biochar based on FTCs modification is obviously better than that of NaOH and KMnO₄. The research results are of great significance to improve the material structure of biochar and the purification effect of CW on city tail water.

Keywords: Biochar; City tail water; Constructed wetland (CW); Freeze-thaw cycle (FTCs); H(2)SO(4).

MeSH terms

Adsorption
Charcoal / chemistry
Water*
Wetlands
Zea mays*

Substances

biochar
Water
Charcoal