H3BO3改性柠檬渣对Cu2+ Pb2+ Cr6+的吸附性能

为研究柠檬渣对Cu2+、Pb2+和Cr6+的吸附性能，利用10%的H₃BO₃对柠檬渣进行了改性，比较了改性前后柠檬渣对Cu2+、Pb2+和Cr6+的吸附效果，并利用差热分析（TG-DTA）、红外光谱（IR）、紫外光谱（UV）、X射线衍射仪（XRD）、扫描电镜（SEM）和能谱（EDS）对柠檬渣进行了表征.结果表明:改性后的柠檬渣对Cu2+、Pb2+和Cr6+的吸附率分别为预处理后柠檬渣的5.89、2.07和1.38倍；改性后柠檬渣的孔径为中孔，孔容增大了3.0倍，孔径和碘吸附值变化不大，灰分率减小了近4倍，比表面积增大超过了2倍.改性后的柠檬渣在近紫外区有最大吸收波长；改性和吸附Cu2+、Pb2+和Cr6+样品的TG和DTA曲线不完全相同；柠檬渣为非晶型结构，主要由C组成；吸附Cu2+、Pb2+、Cr6+后的改性柠檬渣均各自含有Cu、Pb、Cr元素，但形成的能谱（EDS）峰不高.研究显示，柠檬渣经10%的H₃BO₃改性后能显著提高对Cu2+和Pb2+的吸附性能，而对Cr6+的吸附性能影响不大. 

Adsorption Properties of Lemon Residues Chemically Modifed by H3BO3 to Cu2+, Pb2+ and Cr6+

In order to investigate the adsorption properties of lemon residues for Cu2+, Pb2+ and Cr6+, lemon residues were modified by chemical methods with 10% H₃BO₃. The effects of lemon residues on Cu2+, Pb2+ and Cr6+ adsorption were measured before and after modification. The lemon residues were further characterized by TG-DTA, IR, UV, XRD and SEM/EDS. The adsorption efficiencies for Cu2+, Pb2+ and Cr6+ of the modified lemon residue were increased about 5.89, 2.07 and 1.38 times higher than lemon residue after pretreatment, respectively. The modified lemon residue shared a lot of mesopores. The pore volume increased about three times compared with an unmodified sample. The change of the pore size and absorption capacity of iodine was not much observed, and the ash content decreased about four times, while the specific surface areas increased over two times. The maximum absorption band for the modified lemon residues was located at the near ultraviolet region. The TG and DTA curves of the modified and adsorped samples for Cu2+, Pb2+ and Cr6+ were not exactly the same. The structure of the lemon residues were the amorphous structure, which was mainly composed of C. The modified lemon residue that absorbed Cu2+, Pb2+ and Cr6+ contained Cu, Pb and Cr elements respectively, but the formation peak of the EDS was not high.The modified residues could effectively remove Cu2+ and Pb2+.In contrast, the adsorption capacity of Cr6+ had little effect.