二氧化钛纳米颗粒对沼泽土壤反硝化和N_(2)O排放的影响  

Effects of TiO_(2) nanoparticles on the denitrification and N_(2)O emissions of marsh soil

作　　者：范峰华 郑荣波 刘爽 郭雪莲 FAN Fenghua;ZHENG Rongbo;LIU Shuang;GUO Xuelian(Wetland College of Southwest Forestry University,Kunming 650224,China;National Plateau Wetland Research Center,Kunming 650224,China;College of Chemical Engineering,Southwest Forestry University,Kunming 650224,China)

机构地区：[1]西南林业大学湿地学院,昆明650224 [2]国家高原湿地研究中心,昆明650224 [3]西南林业大学化学工程学院,昆明650224

出　　处：《生态学报》2021年第16期6525-6532,共8页Acta Ecologica Sinica

基　　金：云南省基础研究计划项目重点项目(202001AS070041);国家自然科学基金(41563008);云南省高原湿地科学创新团队项目(2012HC007)。

摘　　要：近年来,二氧化钛纳米颗粒(TiO_(2)NPs)环境释放量不断增加,并通过多种途径进入湿地生态系统,不可避免地影响到湿地生态系统环境和功能。然而,关于TiO_(2)NPs对沼泽土壤反硝化作用和氧化亚氮(N_(2)O)排放的影响机及制尚不明确。选择典型沼泽土壤,通过室内培养实验研究土壤理化性质、反硝化酶活性、反硝化速率(DNR)和N_(2)O排放对不同剂量TiO_(2) NPs 0 mg/kg(CK)、10 mg/kg(A10)、100 mg/kg(A100)、1000 mg/kg(A1000)输入的响应,探讨TiO_(2) NPs输入对沼泽土壤反硝化作用和N_(2)O排放影响的内在机制。结果表明:不同剂量TiO_(2) NPs处理显著降低了土壤pH(P<0.05),A10处理显著降低土壤总有机碳(TOC)含量(P<0.01),A1000处理显著降低硝态氮(NO-3-N)和亚硝态氮(NO_(2)^(-)-N)含量(P<0.05)。TiO_(2) NPs处理抑制硝酸盐还原酶(NAR)活性,促进一氧化氮还原酶(NOR)和氧化亚氮还原酶(NOS)活性(P<0.01),A1000处理先促进后抑制了亚硝酸盐还原酶(NIR)活性(P<0.05)。不同剂量TiO_(2)NPs处理抑制了土壤DNR,促进了N2O排放,TiO_(2) NPs处理通过抑制NIR活性,降低土壤DNR,同时通过促进NOR活性,提高N2O排放。综上,TiO_(2)NPs输入通过影响反硝化还原酶活性改变沼泽土壤反硝化过程,导致沼泽土壤N2O排放增加,改变湿地氮的源、汇功能,影响全球气候变化。为TiO_(2) NPs输入的湿地环境风险评估研究提供理论基础。In recent years,with the rapid development of nanotechnology,the increasing production and application of titanium dioxide nanoparticles(TiO_(2)NPs)will lead to their release and accumulation in the environment.Owing to that the wetland is located in a relatively lower water catchment environment,TiO_(2) NPs may enter the wetland ecosystem through multiple pathways,once it enters the wetland ecosystem,it will affect environment and the function of wetland ecosystem and change the process of soil nitrogen transformation inevitably.However,little is known about the effects and mechanism of TiO_(2)NPs input on the denitrification and nitrous oxide(N_(2)O)emissions of marsh soil.In this study,in order to explore the effects and its mechanism of TiO_(2)NPs input on soil denitrification and N_(2)O emissions,marsh soils were collected from typical field and an indoor cultivated experiment with different addition of TiO_(2) NPs was conducted,exposure experiments were conducted to investigate the effects of TiO_(2)NPs(0 mg/kg(CK),10 mg/kg(A10),100 mg/kg(A100),250 mg/kg(A250),and 1000 mg/kg(A1000))on soil physical and chemical properties,denitrifying enzyme activity,denitrification rate and N_(2)O emissions of marsh soil.The results showed that(1)all the addition of TiO_(2)NPs significantly reduced soil pH(P<0.05),the treatments of A10 significantly reduced the content of soil total organic carbon(TOC)(P<0.01),the treatments of A1000 significantly reduced the content of soil nitrate nitrogen(NO_(3)^(-)-N)and nitrite nitrogen(NO_(2)^(-)-N)(P<0.05).(2)The addition of TiO_(2)NPs inhibited the activity of nitrate reductase(NAR)and promoted the activity of nitric oxide(NOR)and nitrous oxide(NOS)(P<0.01),the treatments of A1000 promoted the activity of nitrite reductase(NIR)in initial stage of inhibition,then the trend was opposite(P<0.05),but with the extension of the culture time,the inhibitory effect of TiO_(2)NPs gradually weakened.(3)The addition of TiO_(2) NPs significantly inhibited denitrification rate(DNR)and promoted N

关 键 词：二氧化钛纳米颗粒 反硝化作用 N_(2)O排放 酶活性 沼泽 

分 类 号：X16[环境科学与工程—环境科学] X144