向日葵秸杆生物炭对孔雀石绿的吸附性质

Preparation of Biochar from Unflower Stalk and Its Adsorption Properties for Malachite Green

以向日葵秸秆为基质制备生物炭,并研究生物炭对孔雀石绿染料的吸附性质.设计L9(34)正交试验优化制备条件,考察了生物炭对孔雀石绿吸附的最佳条件、吸附热力学和动力学行为,采用扫描电子显微镜(SEM)、X-射线衍射仪(XRD)和红外光谱仪对生物炭进行表征分析.结果表明,向日葵秸秆生物炭的最佳制备条件为:原料粒径100目、ZnCl2质量分数40%、活化温度600℃、活化时间1.5 h.孔雀石绿染料初始浓度为600 mg/L时,生物炭对染料的吸附量是改性前的5.3倍,Langmuir等温吸附方程能较好地描述生物炭对孔雀石绿的吸附特性,最大理论吸附量为990.09 mg/g.向日葵秸杆生物炭的结晶度是碳化前的2.175倍,结晶组成主要是碳和ZnC,生物炭中O─H、C─O、C=O等在吸附作用中发挥了主要作用.该载锌生物质炭可作为潜在的吸附剂有效去除水体中的孔雀石绿.

The sunflower stalk was used as raw material to prepare the biological adsorbent for the Malachite green dye solution adsorption.The preparation process was subsequently optimized by orthogonal test.Effects of various parameters on the adsorption,adsorption thermodynamic and kinetic characteristics were studied.The resulting material was characterized by scanning electron microscopy(SEM),X-ray diffraction(XRD)and specific surface area analysis.The experimental results show that the optimum conditions for preparing biochar is that zinc choride concentration was 40%,the activation temperature was 600℃,the activation time was 1.5 h and grain size of 100 mesh.Absorption quantity of Malachite green by biochar was 5.3 times as much as that before modification,adsorption behavior was found to agree well with the Langmuir equation,the maximum adsorption capacity was calculated 990.09 mg/g.XRD analysis showed that the crystallinity of sunflower stem biomass carbon obtained after carbonization was 2.175 times higher than that before carbonization.The crystal composition is mainly carbon and ZnC.O-H,C-O and C=O of biochar played a major role in adsorption.Overall,Zn-loaded biomass could offer a protential alternative of adsorbent for malachite green removal from water.