秸秆生物质炭对淹水砖红壤中Cu^(2+)钝化效果的影响  

Effects of Crop-Straw Biochars on Immobilization of Cu^(2+) in an Oxisol Under Submerged Condition

作　　者：赵震杰 方迪[1] 董颖 徐仁扣[2] 周立祥[1] 姜军[2] ZHAO Zhen-jie;FANG Di;DONG Ying;XU Ren-kou;ZHOU Li-xiang;JIANG Jun(College of Resources and Environmental Sciences,Nanjing Agricultural University,Nanjing 210095,China;Institute of Soil Science,Chinese Academy of Sciences/State Key Laboratory of Soil and Sustainable Agriculture,Nanjing 210008,China;School of Chemical Engineering and Pharmacy,Henan University of Science and Technology,Luoyang 471023,China)

机构地区：[1]南京农业大学资源与环境科学学院,江苏南京210095 [2]中国科学院南京土壤研究所/土壤与农业可持续发展国家重点实验室,江苏南京210008 [3]河南科技大学化工与制药学院,河南洛阳471023

出　　处：《生态与农村环境学报》2018年第7期636-642,共7页Journal of Ecology and Rural Environment

基　　金：国家自然科学基金(41371245;41771275;21377057);国家重点研发计划(2017YFF0108201)

摘　　要：秸秆生物质炭在旱作条件下可通过络合重金属阳离子、提高土壤pH值等途径降低重金属活性和有效性,但是淹水条件下生物质炭对重金属形态的影响研究较少。以30 g·kg^(-1)施用量将不同温度条件下制备的油菜和花生秸秆生物质炭及商品活性炭添加到广东徐闻砖红壤中,并添加5 mmol·kg^(-1)Cu(NO_3)_2和20 g·kg^(-1)葡萄糖,淹水培养49 d,采用连续提取法分级提取不同形态Cu^(2+)并研究其动态变化。结果表明,添加活性炭、400℃条件下制备的油菜秸秆炭和300、400、500℃条件下制备的花生秸秆炭后,淹水培养初期土壤溶液pH值比对照组明显增加,酸溶态Cu^(2+)含量显著降低,还原态和氧化态Cu^(2+)含量有所升高。随淹水时间增加,土壤pH值逐渐降低,导致生物质炭处理土壤中酸溶态Cu^(2+)含量显著升高,生物质炭对Cu^(2+)的钝化效果逐渐减弱并消失,还原态和氧化态Cu^(2+)含量降低。在49 d培养时间内残渣态Cu^(2+)含量变化不大。淹水条件下生物质炭对砖红壤中Cu^(2+)的钝化效果并不持久,甚至由于生物质炭中有机物质分解而产生更多有机酸,导致淹水后期生物质炭处理砖红壤pH值较对照低,反而提高了Cu^(2+)的活性和生物有效性。Crop-straw derived biochars inhibited the mobility and bioavailability of heavy metals in the upland cropping land due to complexation,precipitation,as well as increasing soil pH.However,information regarding the influence of biochar on heavy metal speciation in soils under submerged condition is limited.In the present study,the effect of the biochars on Cu speciation in an Oxisol was conducted under submerged condition.The biochars were derived from canola straw pyrolyzed at 400℃and peanut straw at 300,400 and 500℃,respectively.Soil was spiked with Cu(NO 3)2(5 mmol·kg-1)and glucose(20 g·kg-1),respectively,and the loading quantity of biochar is about 30 g·kg-1.The homogenized soil samples were incubated under inundation condition for 49 days.BCR sequential extraction method was used to investigate the dynamic changes of Cu^2+species during the incubation.Results show that addition of activated carbon and crop straw derived biochars significantly increased soil pH,decreased acid-soluble fraction of Cu^2+evidently,and the reducible and oxidizable fraction of Cu^2+showed reverse trends in the early stage of flooding.Whilst,the acid-soluble fraction of Cu^2+increased with the incubation time,mainly due to the decreasing soil pH,which suggested the inhibition function of biochars on Cu^2+mobility faded progressively.Moreover,organic acids produced by decomposition of organic matter in the biochar,lead to a decreasing soil pH,and consequently increased the mobility of Cu^2+.

关 键 词：秸秆生物质炭 砖红壤 淹水培养 BCR分级 Cu^2+形态 

分 类 号：S153.4[农业科学—土壤学] X53[农业科学—农业基础科学]