doi:10.16186/j.cnki.1673-9787.2020080093

Received:2020/08/31

Revised:2020/11/27

Published:2022/03/15

Study on the migration and transformation regularity of natural organic matter in the low-temperature pore geothermal water

LI Yusong1,2, ZHAO Li3,4,5, ZHANG Panqun3,4,5, ZHAO Yu3,4,5, WANG Xinyi3,4,5,6, LI Yaqi3,4,5, KONG Maoran3,4,5

1.No. 2 Institute of Geo-environment Survey,Bureau of Geology and Mineral Exploration and Developlment of Henan Provinve,Zhengzhou  450000 ,Henan ,China；2.Henan Seienee and Teehnology Innovation Center of Natural Resourees ,Zhengzhou  450000 ,Henan,China；3.Henan Key Laboratory of Coal Green Conversion,Henan Polyteehnie University,Jiaozuo  454000 ,Henan,China；4.Shaanxi Key Laboratory of Prevention and Control Teehnology for Coal Mine Water Hazard ,Xian  710077 ,Shaanxi,China；5.Institute of Resourees & Environment,Henan Polyteehnie University,Jiaozuo  454000 ,Henan,China；6.Collaborative Innovation Center of Coalbed Methane and Shale Gas for Central Plains Eeonomie Region,Jiaozuo  454000 ,Henan,China

Abstract: Taking the disturbed soil of Minghuazhen Formation thermal reservoir in Neogene Period bared from the land surface as the packed matrix,and taking the natural organic matter( NOM) extracted from the leaf litter of Populus tomentosa as the research object,the migration and transformation laws of NOM in the low-temperature pore geothermal water were studied through column experiments with a Darcy flux between 0.59 and 0.6 cm /h at 40 ℃ .The results showed that the biodegradation of NOM and its adsorption onto the packed matrix occurred during its transport through the studied matrix between 0 and 820 h.The studied NOM could be transformed to the aromatic organic compounds containing carbonyl,carboxyl,hydroxyl and esters during the test duration.Additionally,there was a significant linear correlation between DOC and UV₂₅₄ ( r₂ = 0.81) .Thereafter,with the decrease of NOM concentration by half in the input solution,the removal efficiency of DOC amounted to nearly 100% between 820 and 1 180 h.When the deionized water was injected into the packed column between 1 180 and 1 828 h,the studied NOM could be removed through strong biodegradation indicated by the variations of DOC and UV₂₅₄ .Moreover,the aromatic compounds in the NOM could be adsorbed by the packed matrix.The above results could be confirmed by the variation patterns of SUVA₂₅₄ and A₂₅₃ /A₂₀₃ .Furthermore,the studied NOM could provide effective carbon sources to promote the complete biotransformation of nitrate between the water and rock.

Key words:natural organic matter;poregeo thermal water;dissolved organic carbon;adsorption;biodegradation

 天然有机质在低温孔隙地热水中的迁移转化研究_李玉嵩.pdf