中文摘要：

为查明豫东某市深埋孔隙型地热水的水化学特征、水质现状及反硝化作用,为地热水的合理开发利用提供依据,对研究区24个地热水水样（埋深在600～1 400 m）的水化学指标进行了统计分析。研究结果表明：研究区地热水水化学类型为HCO3-Na型,为弱碱性软水。随着井深和水温的增加,地热水中的总铁、F-、溶解性总固体（TDS）、HCO3-、NH4＋、SO42-含量均有增加的趋势,并且有不同程度的超标,这与较高的水温有关。硝酸盐含量随井深和水温的变化规律却相反,亚硝酸盐有超标现象。这是由于在碳源缺乏的还原环境下,硝酸盐的不完全反硝化作用易生成亚硝酸盐的中间产物。地热水中NH4＋、HCO3-及SO42-含量均与NO3-含量有一定的负相关关系,这表明在研究区的地热水中,存在有硝酸盐的异养反硝化作用和异化还原作用,同时还可能存在有自养反硝化作用。

英文摘要：

To inspect the hydro-chemical characteristics, water quality and denitrification of the ultra-deep pore geothermal water, derived from a reservoir of a citY in east Henan, 24 geothermal water samples were collected and statistically analyzed from existing domestic tube wells with depths between 600 m and 1 400 m in the study area. The geothermal water as HCO3-Na＋ type is categorized as alkalescent and soft water. With the increasing of well depth and temperature, the contents of total Fe, F-, total dissolved solids, HCO3-, NH4＋ and SO4 2- all increased and even cannot meet the standard level for some samples, which were related to the high water temperature. But the content of nitrate in the study area decreased with well depth and temperature and the nitrite concentration in some water samples cannot meet the standard level, which were due to the incomplete denitrification under anaerobic conditions with limited amounts of carbon sources. The content of HCO3-, NH4＋ and SO4 2- showed certain negative correlation with that of nitrate, respectively, which indicated that the heterotrophic denitrification and dissimilatory nitrate reduction to ammonium （DNRA） occurred in the study area, and autotrophic denitrification might also exist.