超深层孔隙地热水中NH_4^+和NO_2^-的运移规律研究  

On the migration regularity of NH_4^+ and NO_2^- in the in-depth pore geothermal water

作　　者：王心义[1] 张艳欣[1] 刘梦杰[1] 阿丽莉[1] 赵丽[1] 

机构地区：[1]河南理工大学资源环境学院,河南焦作454100

出　　处：《安全与环境学报》2012年第4期14-17,共4页Journal of Safety and Environment

基　　金：国家自然科学基金项目(40972164)

摘　　要：以河南省郑州市明化镇组细砂热储层为岩土介质,模拟地热水温度环境,分别开展溶质溴、亚硝酸盐和氨氮的室内土柱淋滤模拟试验,对比研究其运移规律。结果表明,由CXTFIT 2.0拟合穿透试验数据得到Br-在松散孔隙型细砂热储层中的纵向弥散系数在40℃时为3.735 cm2/h,20℃时为2.057 cm2/h。NO2-在运移过程中存在硝化作用,40℃时的硝化作用比20℃时强。NH4+-N在岩土介质中存在较强的吸附作用。由CXTFIT2.0拟合试验数据得到氨氮在40℃和20℃的阻滞系数Rd分别为79.14、107.3,但其硝化反应可以忽略。并且淋滤过程中,氨氮淋滤液的pH值逐渐上升,40℃时从7.46～7.68增大到8.78,20℃时最大值达到9.04。This paper is engaged in a study of the migration regularity of Br^- , NH4^＋ and NO2^- in the in-depth pore geothermal water by taking Kaifeng City as a ease study sample. For our research purpose, we have carried out the column experiments of Br^- , NH4^＋ and NO2^- at high temperatures in the loose-pore geothermal reservoir matrixes, which have been formulated in the Neogene Period in Minghua Town, Kaifeng, so as to make a comparison of their migration properties. For the non-reactive tracers, Br^- was used to characterize the hydraulic condition of this study and the influence of the temperature on the migration parameters of the fine sand matrix in question. The resuits of our study show that the hydrodynamic dispersion in the simulated sandy column model could be enhanced at the temperature of 40 qC . When CXTFIT 2.0 software was adopted to simulate the break- through curves of Br^- , the longitudinal dispersive coefficients of Br^- at 40 qC and 20 ℃ would be equal to 3.735 cm^2/h and 2.057 cm^2/h, respectively. By the end of each tracer experiment, it was found that the fine sand in the column would be leached for about 24h with deionized water so as to be able to remove the residual salinity caused by the tracer. Later, then, when the nitrite experiment was done at the temperatures of 40 ℃ and 20 ℃, respectively, the flow- ing rate would stay in between 1.75 mIJmin and 1.9 mL/min. During the movement of NO2^- , the concentration of NOr would increase from 1 mg/L to 9.21 mg/L and then dropped to 7.88 mg/L, respectively, at 40 ℃ and 20℃ , the ORP of the filtrate at 40 ℃ turns also to be higher than that at 20 ℃. Thus, it can be found that the nitrification of NO2^- could be enhanced at 40 ℃. When the relative concentration of NO2^- - N（ P/Po ）in the effluent samples turned out to be above 0.98, the columns would be leached with the deionized water until the content of NO2^- - N in the effluent sample dropped below the limit of the determination （ 〈 0.003 mg/L） . However, the a

关 键 词：地球化学 细砂热储层 运移规律 纵向弥散系数 亚硝酸盐 氨氮 溴 

分 类 号：X131.2[环境科学与工程—环境科学]