酸化环境对紫色母岩风化产物交换性盐基离子及其酸缓冲容量的影响  

Effect of the Acidification Environment on Exchangeable Cations and Acid Buffering Capacity of Weathering Products of Purple Parent Rock

作　　者：李春培 李雪 汪璇 刘刚才[2] 赵吉霞 熊俊芬[1] LI Chunpei;LI Xue;WANG Xuan;LIU Gangcai;ZHAO Jixia;XIONG Junfen(College of Resources and Environment,Yunnan Agricultural University,Kunming 650000,China;Key Laboratory of Mountain Surface Processes and Ecological Regulation,Chinese Academy of Sciences,Institute of Mountain Hazards and Environment,Chinese Academy of Sciences,and Ministry of Water Conservancy,Chengdu 610041,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]云南农业大学资源与环境学院,昆明650000 [2]中国科学院山地表生过程与生态调控重点实验室,中国科学院、水利部成都山地灾害与环境研究所,成都610041 [3]中国科学院大学,北京100049

出　　处：《土壤学报》2024年第1期258-271,共14页Acta Pedologica Sinica

基　　金：国家自然科学基金项目(42007002);云南省基础研究计划(202101AT070220)资助。

摘　　要：为研究酸化环境对紫色母岩风化产物交换性盐基离子及其酸缓冲容量的影响,以侏罗纪紫色岩层中的遂宁组(J3s)、沙溪庙组(J2s)和蓬莱镇组(J3p)为研究对象,设置pH分别为2.5、3.5、4.5、5.6等4个酸性环境,以及去离子水(pH=7.0)为对照处理(CK),采用循环浸泡试验和模拟淋溶试验,研究酸性环境对紫色母岩风化产物特征的影响。结果表明,通过酸化环境处理后,3组紫色母岩风化产物交换性盐基离子及其总量均随酸化环境的pH降低而减小,且3组紫色母岩风化产物的酸缓冲容量与其交换性K^(+)、Na^(+)、Ca^(2+)、Mg^(2+)含量以及交换性盐基总量均呈极显著正相关关系(P<0.01)。以pH=7.0(CK)处理为对照,循环浸泡处理后的遂宁组(J3s)、蓬莱镇组(J3p)和沙溪庙组(J2s)风化产物中交换性盐基总量的减小幅度分别为8.75%~18.21%、10.83%~23.18%和5.85%~18.41%。而且模拟淋溶24次后,遂宁组(J3s)、沙溪庙组(J2s)和蓬莱镇组(J3p)风化产物中交换性盐基总量较模拟淋溶12次时分别减小1.77%~24.85%、8.99%~25.75%和8.05%~25.66%。此外,在同一酸度处理下,风化产物中的交换性盐基离子均表现为Ca^(2+)>Mg^(2+)>Na+>K^(+)。本试验中淋溶处理下风化产物酸缓冲容量、交换性盐基离子及盐基总量低于浸泡处理。可见,丘陵地带坡面的矿物或养分的迁移以淋溶作用为主,平地的矿物或养分的迁移以浸泡作用为主。因此,酸沉降可能在一定程度上加速坡面土壤侵蚀的发生,进而导致平原化进程的加速。【Objectives】This study aimed to analyze the influence of the acidification environment on weathering products of the typical purple parent rock.The weathering products of purple parent rocks from the Suining Group(J3s),Shaximiao Group(J2s),and Penglaizhen Group(J3p)were investigated under different acidification environments in the laboratory.【Method】The acid solutions used for acidification of purple parent rock samples were used to cycle soaking and simulate leaching experiment tests at pHs of 2.5,3.5,4.5,and 5.6.In addition,deionized water(pH=7.0)was set as a control treatment(CK).【Result】The results showed that the exchangeable cations and content of total exchangeable cations of weathering products of these purple parent rocks decreased as the acidity of the acidifying solutions increased.The acid buffering capacity of weathering products had an extremely significant correlation with the content of the exchangeable K^(+),Na^(+),Ca^(2+),and Mg^(2+) and the content total of exchangeable cations(P<0.01).Compared with the value at pH=7.0(CK),the total content of exchangeable cations of the weathering products of purple parent rock of the groups J_(3)s,J_(3)p,and J_(2)s in cycle soaking experiment tests decreased by 8.75%-18.21%,10.83%-23.18%,and 5.85%-18.41%,respectively.When the amount of simulated rainfall at 24 times was compared with that at 12 times,the total content of exchangeable cations in J3s,J3p,and J2s decreased by 1.77%-24.85%,8.99%-25.75%,and 8.05%-25.66%,respectively.In addition,the exchangeable cations characteristics of the weathering products were Ca2+>Mg2+>Na+>K+under the same acidity treatment.【Conclusion】The acid buffer capacity,exchangeable salt ions,and total salt of weathering products under the soaking treatment in this experiment were lower than under the leaching treatment.It can be seen that the transport of minerals or nutrients on the slopes of hilly areas is dominated by leaching,while the transport of minerals or nutrients on the plains is dominated by leaching.The

关 键 词：紫色母岩 模拟酸雨 循环浸泡 淋溶 成土特征 

分 类 号：X53[环境科学与工程—环境工程]