Position: Home > Articles > Comparison of the cadmium adsorption characteristics of three types of new modified corn straw biochars
Journal of Anhui Agricultural University
2023
(6)
1006-1012
3种新型改性玉米秸秆生物炭对Cd~(2+)吸附特性的比较
作 者：
陈欣洁;叶燕清;杨浙湘;黄兴洲;周曦;张温尔;李荭荭
单 位：
闽南师范大学历史地理学院
关键词：
巯基改性生物炭;铁改性生物炭;微纳米含氮生物炭;镉;吸附行为
摘 要：
为比较3种新型改性生物炭对溶液中镉(Cd)的吸附行为,以玉米秸秆生物炭为原料,制备巯基改性生物炭(S-BC)、铁改性生物炭(Fe-BC)和氮掺杂生物炭(N-BC),分析改性前后生物炭的元素组成、比表面积、表面官能团等性质的变化,通过系统的吸附试验,比较3种改性生物炭对Cd的吸附性能和作用机理.结果表明:与未改性生物炭(BC)相比,N-BC和Fe-BC比表面积分别增加了6.3和9.0倍,总孔体积分别增加了2.68和4.08倍.S-BC因改性后表面光滑,使得生物炭比表面积减小,但其表面官能团变化明显,S-BC在2 977 cm-1处出现新的吸收峰对应脂肪族(C-H)的伸缩振动,而且在1 089 cm-1、1 044 cm-1位置出现双特征吸收峰.3种生物炭对Cd2+的吸附主要为化学吸附过程为主,且Langmuir吸附等温线模型所拟合的热力学吸附优于Freundlich吸附等温模型,推测N-BC、Fe-BC、S-BC 3种生物炭对Cd2+的吸附过程为单分子层物理吸附.通过Langmuir模型计算可以得到几种生物炭对Cd2+最大吸附量表现为Fe-BC (69.11 mg·g-1)>N-BC (61.92 mg·g-1)>S-BC (53.85 mg·g-1)>BC (40.34 mg·g-1).
译 名：
Comparison of the cadmium adsorption characteristics of three types of new modified corn straw biochars
单 位：
School of History and Geography,Minnan Normal University,Zhangzhou 363000;College of Resources and Environment,Fujian Agricultural and Forestry University,Fuzhou 350002
关键词：
thiol-modified biochar%FeSO4/FeCl3 modified biochar%micro-nano-engineered nitrogenous biochar%cadmium%adsorption
摘 要：
In order to explore the adsorption behavior of Cd2+onto three types of new modified biochars,named as thiol-modified biochar(S-BC),FeSO4/FeCl3 modified biochar(Fe-BC)and nitrogen-containing biochar(N-BC),which were prepared from corn straw biochar(BC),the changes in the elemental composition,specific surface area,surface functional groups and microstructure of the biochars before and after the modification were examined.Through laboratory-based adsorption experiments,the adsorption properties and mechanism of the modified biochar for Cd2+were compared.The results showed that compared with the unmodified biochar(BC),the specific surface area of N-BC and Fe-BC was increased by 6.3 and 9.0 times,respectively,and the total pore volume was increased by 2.68 and 4.08 times,respectively.Due to the smooth surface of S-BC,the specific sur-face area of S-BC was at a lower level than that of BC,while its surface functional groups changed significantly.Fourier transform infrared spectroscopy(FTIR)analysis revealed that a new absorption peak of S-BC was found at 2977 cm-1,and a double characteristic absorption peak appeared at 1089 cm-1 and 1044 cm-1.The adsorptive removal of Cd2+by the three modified biochars could be better simulated with the Langmuir adsorption isotherm model than the Freundlich adsorption isotherm model,suggesting a chemisorption process might participated in the Cd2+removal.In addition,Langmuir,the monolayer adsorption model,was better to explain the mechanism of Cd2+removal by the biochars.The maximum adsorption capacity of these biochars to Cd2+was listed in the order:Fe-BC(69.11 mg·g-1)>N-BC(61.92 mg·g-1)>S-BC(53.85 mg·g-1)>BC(40.34 mg·g-1).
