CO_(2)封存泄漏的稻田土壤细菌监测指标筛选研究

Screening of bacteria monitoring indicators in paddy soil under sealed CO_(2) leakage

为研究CO_(2)地质封存过程中CO_(2)泄漏对水稻及稻田土壤的风险影响,利用CO_(2)模拟泄漏平台,研究了不同CO_(2)泄漏速率下水稻生长、稻田土壤性质与土壤细菌组成及多样性的变化特征.结果表明:随着CO_(2)泄漏速率的增加,稻田土壤pH显著降低,电导率显著增加,水稻生长受到明显抑制;稻田土壤细菌的丰富度指数和多样性指数均有增加,均匀度指数有所降低.CO_(2)泄漏显著改变了稻田土壤细菌组成,稻田土壤的优势菌门中变形菌门、拟杆菌门与绿弯菌门的相对丰度总体降低,而酸杆菌门与放线菌门的相对丰度总体升高;稻田土壤优势菌属中RB41、MND1、厌氧粘菌属及鞘脂单胞菌属的丰度总体升高,而硝化螺旋菌属的丰度总体降低;稀有细菌中CO_(2)泄漏下全部出现的有粘胶球形菌门、柔膜菌门及双头菌属、硫杆菌属,CO_(2)泄漏后全部消亡的为假单胞菌属.建议将变形菌门的减少和酸杆菌门的增加,以及RB41、MND1及厌氧粘菌属的增加作为稻田土壤CO_(2)泄漏监测的推荐指标.

This study aimed to evaluate the potential risk of CO_(2) leakage during the CO_(2) capture and storage(CCS)by the CO_(2) leakage simulation platform.Specifically,a range of parameters including rice growth,properties of paddy soil,and soil bacterial diversity and composition of paddy soil were applied to characterize the adverse effects caused by CO_(2) at different leakage rates.The results showed that with the increase of CO_(2) leakage rate,the pH decreased,the conductivity of paddy soil and the growth of rice were significantly increased and reduced,respectively.Furthermore,compared to the increase of the bacteria richness index and the diversity index of paddy soil,the evenness index decreased.Moreover,the bacterial composition of paddy soil was notably changed by CO_(2) leakage,the relative abundances of Proteobacteria,Bacteroidetes and Chloroflexi in the dominant bacteria phyla of paddy soil generally decreased,while those of Acidobacteria and Actinobacteria increased.At the genus level,the abundances of RB41,MND1,Anaeromyxobacter and Sphingomonas in the dominant genus of paddy soil increased,but Nitrospira decreased.Among the rare bacteria under the CO_(2) leakage,all the phyla of Lentisphaerae,Tenericutes and the genus of Labrys,Sulfurifustis appeared,and the genus Pseudohongiella all disappeared.Taken together,the decrease of Proteobacteria and the increase of Acidobacteria,and the increase of RB41,MND1 and Anaeromyxobacter can be used as markers for monitoring CO_(2) leakage in paddy soil.