抚顺西露天矿油页岩干馏废渣的浸淋特性分析  

LEACHING AND DISSOLVING CHARACTERISTICS OF OIL SHALE RETORTING SOLID WASTE FROM FUSHUN WEST OPEN PIT

作　　者：李亮[1] 金容 刘琛 李朝辉 王雪峰 LI Liang;JIN Rong;LIU Chen;LI Chao-hui;WANG Xue-feng(School of Resources and Civil Engineering,Northeastern University,Shenyang 110819,China;Fushun Mining Group Co.,Ltd,Fushun 113006,China)

机构地区：[1]东北大学资源与土木工程学院,沈阳110819 [2]抚顺矿业集团有限责任公司,辽宁抚顺130006

出　　处：《环境工程》2021年第3期183-188,共6页Environmental Engineering

基　　金：国家重点研发计划项目(2017YFC1503105)。

摘　　要：油页岩属于非常规油气资源,在低温干馏过程中会产生大量干馏废渣,长期堆积可能会对地下水体造成污染。以抚顺西露天矿回填油页岩干馏废渣为研究对象,在模拟抚顺降水条件下,探究了油页岩干馏废渣浸溶与淋溶过程中pH、电导率、SO_(4)^(2-)、NO^(-)_(3)的溶出特性。结果表明:在酸性条件下,废渣中的Ni和Fe溶出浓度超过GB/T 14848—2017《地下水质量标准》Ⅲ类饮用标准,会对周围地下水环境产生一定影响。因油页岩干馏废渣中有大量的碱性氧化物、酸性氧化物以及有机质,其有较强的pH缓冲能力,但在浸溶5 d后,pH急剧下降至5.5,可能是废渣中的有机物发酵分解产生小分子酸。此外,油页岩干馏废渣中NO^(-)_(3)的溶出规律存在明显特异性,在浸溶时,在酸性和中性条件下,NO^(-)_(3)溶出浓度随着时间延长逐渐降低;而在淋溶时,NO^(-)_(3)浓度逐渐提高至600 mg/L,并产生了大量的NO^(-)_(2)。这可能是因为浸溶为缺氧/厌氧条件,油页岩干馏废渣中的反硝化菌等微生物可能在缺氧环境下将NO^(-)_(3)还原。而淋溶为微氧/好氧条件,在氨化细菌、亚硝酸盐细菌和硝酸盐细菌等作用下,将有机氮逐渐氧化为NO^(-)_(2)和NO^(-)_(3),导致NO^(-)_(2)和NO^(-)_(3)的大量累积。因此,可通过控制油页岩干馏废渣的氧化还原环境来减少有害物质的溶出。Oil shale is a kind of unconventional oil and gas resource.Nevertheless,the solid waste produced in oil shale retorting caused groundwater pollution when accumulated for a long term.In this experiment,backfill(oil shale retorting solid waste)from Fushun West Open-pit was taken as the research object,under the simulated Fushun precipitation condition,to explore the characteristics of pH,conductivity,SO_(4)^(2-),NO^(-)_(3) in the process of leaching oil shale retort waste residue.The results showed that under acidic condition,the leaching concentration of Ni and Fe in the waste residue exceeded the classⅢin drinking standard specified in the Groundwater Quality Standard(GB/T 14848—2017),which would have a certain impact on the surrounding environment.Moreover,due to plenty of basic oxides,acid oxides and organic matters,oil shale retorting waste residue had strong pH buffer capacity.However,after 5 days of leaching,the pH value dropped sharply to 5.5,which probably caused by the fermentation and decomposition of organic matters in the waste residue to produce small molecular acids.In addition,the dissolution regulation of NO^(-)_(3) had obvious specificity.During leaching process,with the extension of time,the concentration of NO^(-)_(3) gradually decreased under acidic and neutral conditions;while in leaching process,the concentration of NO^(-)_(3) gradually increased to 600 mg/L,and high concentration of NO^(-)_(2) appeared.Due to the anoxic/anaerobic condition of leaching,denitrifying bacteria and other microorganisms in oil shale retorting waste residue might reduce NO^(-)_(3).Under the action of ammoniating bacteria,nitrite bacteria and nitrate bacteria,organic nitrogen could be gradually oxidized to NH+4,NO^(-)_(2) and NO^(-)_(3),which led to the accumulation of NO^(-)_(2) and NO^(-)_(3).Therefore,the dissolution of harmful substances could be reduced by controlling the redox environment of oil shale retorting waste residue.

关 键 词：抚顺西露天矿 油页岩干馏废渣 浸淋 氮 

分 类 号：X741[环境科学与工程—环境工程]