二氧化碳在盐碱水中溶解及溢出的实验研究

Experiment Study on Dissolution and Spillover of CO_2 in Saline-Alkaline Water

实验室条件下,将空气、体积分数1%CO_2、5%CO_2、100%CO_2分别通入实验室制备盐碱土-水混合样(#1)、现场取样盐碱水(#2)、黄河水(#3)3种样品中,考察了不同样品中pH值的变化以及不同温度下CO_2的溢出速率。研究结果表明:#1通入100%CO_2,pH值降低到6.62后变化速率趋于平缓,有效地中和土壤碱性同时避免了因通入CO_2而带来的土壤酸化问题,CO_2的溢出速率随着温度的增加而加快,24h后基本达到平衡,pH值不再上升;#2和#3通入100%CO_2后pH值分别降低到5.51和5.43,当温度达到40℃时,20h后CO_2基本全部溢出,样品呈中性,并随着温度的升高,CO_2溢出速率加快。本实验为实际利用烟气CO_2精准释控改造盐碱地提供了基础数据。

Air,Carbon dioxide with 1%(vol),5%(vol)and 100%(vol)were respectively injected into saline-alkali soil-water mixture(#1),on-site sampling of saline water(#2)and Yellow River water(#3)under laboratory condition.Two factors of the pH value and the spillover rate of CO2 were investigated in three samlpes.The results showed that the rate of change became gentle after the pH reduced to 6.62 when the 100%CO2 was introduced into#1,which effectively neutralized the alkaline soil and avoided the soil acidification caused by the CO2.The pH reached the equilibrium after 24 hwith the increase of the temperature.The pH values of#2 and #3 decreased to 5.51 and 5.43 respectively after passing 100%CO2.When the temperature reached 40℃,CO2 basically all overflowed after 20 h,reached neutral,and as the temperature increases,CO2 overflow rate accelerated.This experiment provided a date foundation for the actual use of flue gas CO2 to improve saline land and fully realize the precise release and control of CO2 utilization.