松果对废水中Cu^(2+)、Pb^(2+)、Zn^(2+)的吸附特性研究

Adsorption characteristics of pinecone to Cu^(2+),Pb^(2+) and Zn^(2+) in wastewater

以松果作为吸附剂进行了去除废水中Cu2+、Pb2+、Zn2+的吸附及解吸试验,研究了溶液pH值、吸附剂投加量、反应时间、溶液初始浓度对吸附效果的影响,以及不同pH值对达到吸附平衡的松果的解吸影响。结果表明:当pH值为5.0～5.5,Cu2+、Pb2+、Zn2+初始质量浓度约为25 mg/L时,吸附剂的最佳投加量分别为3、1.5、3 g/L,去除率分别为55.32%、86%、39.96%。3种重金属离子的吸附动力学方程符合Lagergren准二级动力学方程,R2均大于0.998。等温吸附研究表明:Freundlich方程能较好地描述Cu2+的等温吸附过程,Langmuir方程则能更好地描述Pb2+和Zn2+的吸附过程,用Langmuir方程拟合等温吸附数据得出松果对Cu2+、Pb2+、Zn2+的最大吸附量分别为9.10、31.65和9.60 mg/g。强酸是一种理想的Cu2+和Zn2+解吸剂。

The adsorption and desorption experiment for Cu2＋,Pb2＋ and Zn2＋ removal from wastewater was carried out with pinecone as adsorbent,the influences of pH value,adsorbent dosage,reaction time and initial concentration of heavy metal ions on adsorption effect were evaluated,and the effect of pH value on the desorption performance of the pinecone which had realized adsorption equilibrium was also studied.The results showed that： when the pH value was 5.0-5.5,the initial mass concentration of Cu2＋,Pb2＋ and Zn2＋ were all about 25 mg/L,the optimal dosage of adsorbent were 3,1.5 and 3 g/L respectively,the removal rates of the said three kinds of heavy metal ions were 55.32%,86% and 39.96% respectively.The adsorption of those heavy metal ions could be described by Lagergren pseudo-second-order kinetic equation,all R2 exceeded 0.998.The isothermal adsorption study showed that： Freundlich equation could describe the process of Cu2＋ isothermal adsorption quite well,and Langmuir equation was suitable for decribing the process of Pb2＋ and Zn2＋ adsorption.The maximum adsorption capability of pinecone to Cu2＋,Pb2＋ and Zn2＋ which determined through isothermal adsorption data fitting by Langmuir equation were 9.10,31.65 and 9.60 mg/g respectively.Strong acid was a perfect desorbent for Cu2＋ and Zn2＋.