为了解地质封存CO2注入井破裂等快速泄漏或者通过地质甬道缓慢弥散对植物的影响,该文试验通过箱体模拟地质封存CO2快速和慢速的不同泄漏方式,研究其对植物的影响.结果表明:快速泄漏CO2时,泄漏量在2000 g/(m·d)时光合值下降明显(从(22.86±0.89)μmol/(m·s)下降到(0.1±0.08) μmol/(m·s)),植株高度从(206±10.20)cm 下降到(93.67±4.78)cm,叶片数也明显减少,而CO2慢速泄漏时,在浓度控制下植物没有明显的响应,只有长期暴露在CO2泄漏源附近的土壤pH值下降.碳捕集与封存技术(carbon capture and storage,CCS)决策者可以根据地质封存CO2泄漏速度差异对周围生态造成的不同影响制定相应的应对措施.%Carbon capture and storage (CCS) is an effective means to reduce greenhouse gas emissions, which sequesters anthropogenic CO2in deep geological formations and avoids emissions into the atmosphere while supporting coal use. Thus, the technology is an attractive way of controlling greenhouse gases in economies heavily dependent on coal energy, such as China, whose goal is to reach an emissions cap by 2030. Currently, more than 12 CCS demonstration projects are in development in China. Preliminary estimates show that reservoirs, such as saline aquifers, depleted oil and gas reservoirs, and un-mineable coal seams, have a CO2storage capacity with hundreds of billions of tons. However, there are risk of CCS-stored CO2leaking out of the storage reservoirs, and the quick leakage such as failure of injection wells and slow leakage from geological aisle, which shows different environmental impacts. The most visible impact of CCS leakage is the degradation of plant cover. To know the impact of elevated soil CO2flux in near-surface ecosystems and the plants' responses to different CO2leaking rates, and to assess and address the risks of elevated soil CO2flux, we simulated quick and slow CO2leakage, at a rate of 2000 g/(m·d) and 60% of the soil CO2concentration, and compared the differences of maize plant height, root length, leaf number, leaf photosynthetic rate and soil pH value. The experimental device was the self-made combination with gas chambers and soil chambers on top. CO2was injected into the bottom of the cultivation container at different flux rates by manually control. The results indicated that, under the quick CO2leaking at a rate of 2000 g/(m·d), the maize photosynthetic rate was decreased from (22.86±0.89) μmol/(m·s) of CK treatment to (0.1±0.08) μmol/(m·s) , while the height of maize was dropped from (206±10.20) cm to (93.67±4.78) cm and maize root length was decreased by 75%, from (109±16.83) cm to (20.73±3.73) cm. And the number of plant leaves was decreased significantly, which was 16 in the control group, but only 9 to 11 in the rapid leakage control, and the withered leaf number were significantly increased in the rapid leakage test. Slow leakage under 60% of the soil CO2concentration did not inhibit the growth of maize. The height of maize plants in the control group (SCK) was (153.25±13.27) cm, and the plant height at slow leakage treatment was (154 ± 8.09) cm. The root length, the number of leaves and net photosynthetic rate of maize also were not significant difference, separately. Only the soil pH value in the vicinity of leaking source was decreased slightly, however, soil pH value remained within a reasonable range of maize growth and therefore did not have a significant impact on maize growth. The different response of plant to quick and slow stored CO2leakage will provide useful information for decision maker to formulate countermeasures.
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