摘要
以稻壳制备成的稻壳炭为原材料,并经碱溶液活化制成改性稻壳炭吸附剂,表征其吸附性能机理,为农业废弃物稻壳的开发利用提供理论指导。通过单因素实验探究了吸附剂投加量、Pb^(2+)或Cd^(2+)的初始质量浓度、pH值、振荡速度、吸附时间、温度6个因素对Pb^(2+)或Cd^(2+)吸附效果的影响,通过红外光谱、扫描电镜测定了改性前后及吸附前后稻壳炭的表面官能团及形貌结构,通过正交实验探究吸附最佳实验条件,发现改性吸附剂对Pb^(2+)或Cd^(2+)的吸附效果比未改性的好。正交实验表明改性稻壳炭对Pb^(2+)吸附的适宜条件为10.0 g/L的吸附剂投加量、50 mg/L的Pb^(2+)初始质量浓度、pH值为4.00、2.0 h、25℃,吸附率可达97.47%;对Cd^(2+)吸附的适宜条件为8.0 g/L的吸附剂投加量、50 mg/L的Cd^(2+)初始质量浓度、pH值为4.50、2.0 h、25℃,吸附率可达98.75%。同等实验条件下,当质量浓度<60 mg/L时,改性稻壳炭的吸附率Cd^(2+)>Pb^(2+),反之则相反。准二级动力学模型、Langmuir吸附等温线能更好地描述改性稻壳炭对Pb^(2+)和Cd^(2+)的吸附特性。经碱溶液改性后的稻壳炭孔隙结构更为发达,吸附性能良好,可用于处理重金属废水,具有将农业废弃物资源循环利用的价值和前景。
Using rice husk charcoal prepared from rice husk as raw material,and activated by alkali solution to make modified rice husk charcoal adsorbent,the mechanism of adsorption performance was characterized.Six factors such as the dosage of adsorbent,the initial mass concentration of Pb^(2+) or Cd^(2+),pH value,oscillation speed,adsorption time,and temperature were investigated for the effect of Pb^(2+) or Cd^(2+) through single-factor experiments.The surface functional groups and morphology of rice husk carbon before and after modification and adsorption were determined by FTIR and SEM.The optimum experimental conditions of adsorption were investigated by orthogonal experiment.The adsorption effect of modified adsorbent on Pb^(2+) or Cd^(2+) is better than that of unmodified adsorbent.Orthogonal experiments showed that the suitable conditions for Pb^(2+) adsorption by modified rice husk carbon were as follows:adsorbent dosage of 10.0 g/L,initial mass concentration of 50 mg/L,pH of 4.00,adsorption time of 120 min,temperature of 25℃,and the removal rate could reach 97.47%.The suitable conditions for adsorption of Cd^(2+) were as follows:adsorbent dosage of 8.0 g/L,initial mass concentration of 50 mg/L,pH of 4.50,adsorption time of 120 min,temperature of 25℃,and the removal rate could reach 98.75%.Under the same experimental conditions,when the mass concentration was<60 mg/L,the adsorption rate of modified rice husk carbon Cd^(2+)>Pb^(2+),and the reverse is true.The biosorption kinetics of Pb^(2+) and Cd^(2+) by modified rice hull carbon followed the second-order kinetics model very well and adsorption isotherm were well described by the Langmuir isotherm model.The rice husk carbon modified by alkali solution has more developed pore structure and good adsorption performance,and it can be used to treat heavy metal wastewater and has the value and prospect of recycling agricultural waste resources.
作者
林美珊
郑虹
王志辉
褚东宇
LIN Mei-shan;ZHENG Hong;WANG Zhi-hui;CHU Dong-yu(Fujian Provincial Key Laboratory of Coastal Basin Environment,Fujian Polytechnic Normal University,Fuqing 350300,China;College of Materials and Environmental Engineering,Fujian Polytechnic Normal University,Fuqing 350300,China;College of Food and Biological Engineering,Fujian Polytechnic Normal University,Fuqing 350300,China)
出处
《武汉轻工大学学报》
2021年第5期49-60,共12页
Journal of Wuhan Polytechnic University
基金
近海流域环境测控治理福建省高校重点实验室2019年度开放基金(S1-KF1904).
