摘要
为提高单一吸附剂(地质聚合物或生物炭)的吸附量,以矿渣和玉米秸秆生物炭为原料、氢氧化钠为激发剂,制备了地质聚合物-生物炭复合材料(G3.0BC10)。通过水溶液吸附实验测试了其对Pb^(2+)的吸附性能,考察了溶液pH、吸附剂投加量,以及Cu^(2+)、Zn^(2+)和苯酚对G3.0BC10吸附Pb^(2+)性能的影响,通过吸附动力学模型和吸附等温线模型拟合了其对Pb^(2+)的吸附过程。通过XRD、SEM、FTIR、BET表征,推测了G3.0BC10对Pb^(2+)的吸附机制。结果表明,在硅铝比(即SiO_(2)与Al_(2)O_(3)的质量比)为3.0、玉米秸秆生物炭加入量为矿渣总质量的10%条件下制备的G3.0BC10比表面积(55.6 m^(2)/g)比无玉米秸秆生物炭掺杂制备的G3.0(15.5 m^(2)/g)增加了258.7%,所含羟基、羧基等官能团数量明显增多。当溶液pH=5~7、投加量为1 g/L时,G3.0BC10对100 mL初始质量浓度为500 mg/L的硝酸铅溶液中Pb^(2+)去除率达到了99%以上。G3.0BC10对Pb^(2+)的吸附是以物理吸附为主的单分子层吸附过程,更符合拟二级动力学模型(R^(2)=0.9354)和Langmuir等温吸附模型,饱和吸附量为943.217 mg/g。Cu^(2+)、Zn^(2+)的存在降低了G3.0BC10对Pb^(2+)吸附量,而苯酚的存在稍微提高了G3.0BC10对Pb^(2+)吸附量。6次循环使用后,G3.0BC10对Pb^(2+)去除率从99.9%降至80.0%,其对Pb^(2+)的吸附机制包括络合作用、离子交换作用、结构吸附作用,生物炭的添加改善了地质聚合物的孔隙结构,增大了其比表面积,并提供了丰富的含氧官能团。
In order to improve the adsorption capacity,a geopolymer-biochar composite material G3.0BC10 was synthesized using slag and corn straw biochar as raw materials and sodium hydroxide as activator,and evaluated via aqueous solution adsorption experiments for its Pb^(2+)adsorption performance.The effects of solution pH,adsorbent dosage,Cu^(2+),Zn^(2+)and phenol on the adsorption performance of G3.0BC10 for Pb^(2+)were analyzed,with the adsorption process simulated by the kinetics and isotherm models and the adsorption mechanism explored by XRD,SEM,FTIR and BET characterization.The results showed that the specific surface area(55.6 m^(2)/g)of G3.0BC10,prepared with a silicon-aluminum ratio(the mass ratio of SiO_(2)to Al_(2)O_(3))of 3.0 and a corn straw biochar addition of 10%of the total mass of slag,was 258.7%higher than that of G3.0(15.5 m^(2)/g)prepared without corn straw biochar,with hydroxyl and carboxyl groups increased significantly on the surface of G3.0BC10.When the solution pH was 5~7 and G3.0BC10 dosage was 1 g/L,the Pb^(2+)removal rate of 100 mL lead nitrate with a mass concentration of 500 mg/L reached>99%.The adsorption of Pb^(2+)by G3.0BC10 was a monolayer adsorption process dominated by physical adsorption,which was more in line with the pseudo-second-order kinetic model(R^(2)=0.9354)and Langmuir isotherm adsorption model,with the saturated adsorption capacity of 943.217 mg/g.The presence of Cu^(2+)and Zn^(2+)reduced,while the presence of phenol slightly increased the adsorption capacity of G3.0BC10 for Pb^(2+).After 6 cycles,the removal rate of Pb^(2+)by G3.0BC10 decreased from 99.9%to 80.0%.The adsorption mechanism included complexation,ion exchange and structural adsorption.The addition of biochar improved the pore structure of geopolymer,increased its specific surface area and provided abundant oxygen-containing functional groups.
作者
董宴桥
刘俊芳
崔潮
刘霖
郑林冲
DONG Yanqiao;LIU Junfang;CUI Chao;LIU Lin;ZHENG Linchong(School of Civil Engineering,Inner Mongolia University of Technology,Hohhot 010051,Inner Mongolia,China)
出处
《精细化工》
北大核心
2025年第10期2243-2250,共8页
Fine Chemicals
基金
国家自然科学基金项目(52368035)。
关键词
地质聚合物
生物炭
吸附性能
吸附机制
水处理技术
geopolymers
biochar
adsorption properties
adsorption mechanism
water treatment technology
