葎草叶对染料废水中结晶紫吸附性能研究

Study on the adsorption of CV from dye wastewater by humulus japonicus leaves

以制备高性能、价格低廉的新型染料废水生物吸附剂为目标,对色度大、生物难降解、危害大的染料废水进行吸附实验研究。利用制备的葎草叶对结晶紫进行吸附,考察了吸附时间、pH、葎草叶投加量、结晶紫初始质量浓度、温度对吸附过程的影响,并通过吸附等温线、吸附热力学、吸附动力学对吸附机理进行描述。结果表明:在葎草叶投加量为0.4g、pH=7、温度298K、吸附时间60min、结晶紫初始质量浓度为100mg/L条件下,吸附效果较优,吸附率可达96.8%,平衡吸附量与结晶紫初始质量浓度呈正相关;葎草叶吸附结晶紫的吉布斯自由能ΔG<0,焓变ΔH>0,熵变ΔS>0,表明吸附过程是自发的吸热过程;吸附过程更符合Freundlich等温吸附模型;吸附动力学符合准二级动力学模型,葎草叶对结晶紫的吸附以化学吸附为速率控制步骤,结晶紫主要吸附在葎草叶表面。内扩散动力学模型研究表明,葎草叶对结晶紫的吸附过程存在膜扩散和内部扩散。葎草叶作为吸附剂可有效地去除染料废水中的结晶紫,为染料废水生物治理提供了新的方法和思路。

The objective of preparing high-performance,low-cost biological adsorbent for printing and dyeing wastewater was took,and the adsorption experiment of dyestuff wastewater with high chromaticity and high biodegradability was studied.The crystalline violet(CV)was adsorbed by the prepared humulus japonicus leaves(HJ),the effects of adsorption time,pH,dosage of adsorbent,initial CV concentration and temperature on the adsorption process were investigated.The adsorption mechanism was described by adsorption isotherm,adsorption thermodynamics and adsorption kinetics.The results showed that:when HJ was added 0.4 g and pH was 7,the temperature was 298 K,adsorption was carried out for 60 min,simulated dye wastewater,adsorption efficiency of crystal violet of 100 mg/L were excellent,adsorption rate reached up to 96.8%,the equilibrium adsorption rate was positively correlated with the initial concentration of CV dye.Humulus leaves adsorption CV Gibbs free energy ofΔG<0,ΔH>0,ΔS>0 showed spontaneous adsorption process.The adsorption process was more suitable for the freundlich isothermal adsorption equation,the adsorption kinetics accorded with the quasi two level kinetic model.The adsorption of the CV dye molecule by the HJ was chemically adsorbed as the rate control step,the CV molecule was mainly adsorbed on the surface of the HJ.The model of internal diffusion kinetics showed that there was membrane diffusion and internal diffusion of the HJ in the process of CV adsorption.The experimental results showed that HJ as adsorbent can effectively remove crystal violet from dye wastewater,and the research results provided a new method and idea for biological treatment of dye wastewater.