CAJ | 학술논문

　　改良盐碱地对于保障我国粮食安全、生态环境保护及经济社会可持续发展具有非常重要的意义。近20年来，火力发电厂燃煤烟气脱硫石膏已成功地应用于我国北方盐碱地的改良。作为燃煤电厂的废弃物，脱硫石膏含有一些重金属元素，这些重金属元素随着脱硫石膏改良盐碱地而进入土壤中。目前，还很少有针对这些重金属对土壤环境影响的研究。为了评估脱硫石膏——特别是脱硫石膏中携带的重金属——在改良盐碱地后对作物和生态环境可能造成的影响，从而为今后大面积示范推广脱硫石膏改良盐碱地提供依据，以燃煤烟气脱硫石膏作为改良剂，测量了不同脱硫石膏添加比例下盐碱土的土壤碱化度（ESP）、酸碱度（pH值）和电导率（EC）随脱硫石膏添加量变化。通过土柱淋滤实验，分析研究了加入不同重量比例脱硫石膏的不同盐碱土壤层中重金属Pb、Cd、Cr、As、Hg含量分布。结果显示，加入脱硫石膏的盐碱土壤pH值、电导率值、及碱化度有明显降低，表明脱硫石膏对于盐碱土具有明显的改良作用。总体而言，脱硫石膏的加入并未引起土壤重金属含量的显著变化。随着脱硫石膏的加入，在60~80 cm土层中镉（Cd）含量增加、汞（Hg）含量在40~60 cm土层中增加、而土柱其余各层中的铅（Pb）含量均明显低于0~20 cm 表层土壤。这些重金属的不同分布状态是其在土壤中迁移特性决定的。重金属在各土层中的最高含量均符合GB 15618—1995国家土壤环境安全标准，表明脱硫石膏在改良盐碱土过程中不会导致土壤重金属污染而影响土壤环境质量。
　　개량염감지대우보장아국양식안전、생태배경보호급경제사회가지속발전구유비상중요적의의。근20년래，화력발전엄연매연기탈류석고이성공지응용우아국북방염감지적개량。작위연매전엄적폐기물，탈류석고함유일사중금속원소，저사중금속원소수착탈류석고개량염감지이진입토양중。목전，환흔소유침대저사중금속대토양배경영향적연구。위료평고탈류석고——특별시탈류석고중휴대적중금속——재개량염감지후대작물화생태배경가능조성적영향，종이위금후대면적시범추엄탈류석고개량염감지제공의거，이연매연기탈류석고작위개량제，측량료불동탈류석고첨가비례하염감토적토양감화도（ESP）、산감도（pH치）화전도솔（EC）수탈류석고첨가량변화。통과토주림려실험，분석연구료가입불동중량비례탈류석고적불동염감토양층중중금속Pb、Cd、Cr、As、Hg함량분포。결과현시，가입탈류석고적염감토양pH치、전도솔치、급감화도유명현강저，표명탈류석고대우염감토구유명현적개량작용。총체이언，탈류석고적가입병미인기토양중금속함량적현저변화。수착탈류석고적가입，재60~80 cm토층중력（Cd）함량증가、홍（Hg）함량재40~60 cm토층중증가、이토주기여각층중적연（Pb）함량균명현저우0~20 cm 표층토양。저사중금속적불동분포상태시기재토양중천이특성결정적。중금속재각토층중적최고함량균부합GB 15618—1995국가토양배경안전표준，표명탈류석고재개량염감토과정중불회도치토양중금속오염이영향토양배경질량。
Flue gas desulfurization (FGD) gypsum has been applied as an amendment to saline and sodic soils for nearly two decades. It has been proven that FGD gypsum is effective for reclaiming sodic soils. However, as a byproduct from wet desulfurization process, FGD gypsum thus contains some heavy metals either from coal or from limestone. The heavy metals that have entered the soils amended with FGD gypsum may be leached to the soil environment. To date, very few data are available to show the potential environmental risks of the heavy metals introduced by FGD gypsum on the soils. The migration of these extra heavy metals in the soils remains unclear. In this paper, soil column leaching experiments were carried out to investigate the distribution profiles of heavy metals, such as Pb, Cd, Cr, As and Hg, in different soil horizons. The results showed that the pH value, total dissolved salts (TDS) and exchangeable sodium percentage (ESP) significantly decreased in the FGD gypsum amended soils compared with those in the unamended soil. No significant accumulation of heavy metals was found in the soils with the introduction of FGD gypsum. However, Cd and Hg contents increased slightly in 60-80 cm and 40-60 cm horizons respectively, while Pb content in each horizon were significantly lower than those in the top surface horizon. Moreover, the contents of the heavy metals in the soils were well complied with the Environmental Quality Standard for Soils in China (GB 15618—1995), which implied that FGD gypsum would not deteriorate the soil environmental quality.