不同植物基生物炭对NH_(4)+及Cd(Ⅱ)的吸附特性  

Adsorption characteristics of NH4+and Cd(Ⅱ)by different plant-based biochars

作　　者：程钰莹 王嘉铭 王平 朱健[1,2] 陈润华 向思源 罗思远[1,2] CHENG Yuying;WANG Jiaming;WANG Ping;ZHU Jian;CHEN Runhua;XIANG Siyuan;LUO Siyuan(College of Environmental Science and Engineering,Central South University of Forestry&Technology,Changsha 410004,Hunan,China;Hunan Engineering Laboratory for Control of Rice Quality and Safety,Central South University of Forestry&Technology,Changsha 410004,Hunan,China;No.104 Geological Brigade,Bureau of Geology and Mineral Exploration and Development,Duyun 558000,Guizhou,China)

机构地区：[1]中南林业科技大学环境科学与工程学院,湖南长沙410004 [2]中南林业科技大学稻米品质安全控制湖南省工程实验室,湖南长沙410004 [3]贵州省地质矿产勘查开发局一〇四地质大队,贵州都匀558000

出　　处：《中南林业科技大学学报》2022年第3期180-192,共13页Journal of Central South University of Forestry & Technology

基　　金：湖南省重点研发计划项目(2019SK2191);湖南省教育厅科学研究一般项目(19C1900);湖南省高校创新平台开放基金项目(19K107);长沙市科技局重点国际合作项目(kq1801078)。

摘　　要：【目的】为解决水体富营养化、重金属镉污染的问题,选取3种不同植物基生物炭(木炭、竹炭、谷壳炭)作为吸附剂探究其对水溶液中NH_(4)^(+)和Cd(Ⅱ)的吸附性能和机理。【方法】运用扫描电镜(SEM)、傅里叶变换红外光谱(FTIR)和X射线衍射光谱(XRD)等技术手段对3种植物基生物炭进行表征,分析了其理化结构特性。同时采用单因素试验探究了吸附时间和溶液初始pH值等不同条件对吸附的影响,并利用吸附等温线、动力学模型以及一系列表征手段探讨了吸附机理。【结果】3种植物基生物炭对NH_(4)^(+)的吸附量随着吸附时间的增加而增加,100 min后基本趋于平衡。随着pH值、温度、投加量和NH_(4)^(+)初始浓度的增大,吸附量均先增大后减小。3种植物基生物炭对Cd(Ⅱ)的吸附量整体随着pH值、吸附时间的增加而增加,且pH值在6.0之间时,3种生物炭对Cd(Ⅱ)的吸附效果较好;随着Cd(Ⅱ)初始浓度的增加,吸附量先增大后趋于平缓;随着炭投加量的增加吸附量逐步减小后趋于平缓;温度对于3种生物炭吸附Cd(Ⅱ)的效果影响较为复杂。对数据进行拟合,发现3种生物炭对NH_(4)^(+)和Cd(Ⅱ)的吸附更符合Langmuir模型,经计算,25℃条件下,木炭、竹炭和谷壳炭对NH_(4)^(+)和Cd(Ⅱ)的最大吸附量分别为7.37和11.38 mg/g、5.54和9.61 mg/g、7.96和11.07 mg/g。对NH_(4)^(+)的吸附,木炭更符合二级动力学模型,竹炭、谷壳炭更符合一级动力学模型;对Cd(Ⅱ)的吸附均符合二级动力学模型。【结论】谷壳炭、木炭、竹炭是廉价易得且吸附能力较好的吸附材料。【Objective】In order to solve the problem of water eutrophication and heavy metal cadmium pollution,three different plantbased biochars(charcoal,bamboo charcoal,chaff charcoal)were selected as adsorbents to explore their effects on NH_(4)^(+)and Cd(Ⅱ)in aqueous solution.【Method】Three plant-based biochars were characterized by scanning electron microscopy(SEM),fourier transform infrared spectroscopy(FTIR)and X-ray diffraction spectroscopy(XRD),and their physicochemical structural properties were analyzed.At the same time,the effect of different conditions such as adsorption time and initial pH value of the solution on adsorption were investigated by single-factor experiments,and the adsorption mechanism was discussed by using adsorption isotherms,kinetic models and a series of characterization methods.【Result】The results showed that the adsorption capacity of NH_(4)^(+)by the three biochars increased with the adsorption time,and basically tended to balance after 100 min.With the increase of pH value,temperature,dosage and initial NH_(4)^(+)concentration,the adsorption capacity of NH_(4)^(+)increased first and then decreased.The adsorption capacity of Cd(Ⅱ)by the three plant-based biochars increased with the increase of pH value,adsorption time,and when the pH value was 6.0,the three types of biochars had a better adsorption effect on Cd(Ⅱ).With the increase of the initial concentration of Cd(Ⅱ),the adsorption capacity first increased and then tended to saturate.With the increase of the dosage of the three plant-based biochars,the adsorption capacity gradually decreased and then tended to saturate.The effect of temperature on the adsorption of Cd(Ⅱ)was complex.By fitting the data,it was found that the adsorption of NH_(4)^(+)and Cd(Ⅱ)by the three biochars was more in line with the Langmuir model.It was calculated that the maximum adsorption capacities of NH_(4)^(+)and Cd(Ⅱ)by charcoal,bamboo charcoal and chaff charcoal at 25℃were 7.37 and 11.38 mg/g,5.54 and 9.61 mg/g,7.96 and 11.07 mg/g,

关 键 词：生物炭 吸附性能 吸附机理 氨氮 镉 

分 类 号：S727.28[农业科学—林木遗传育种]