粟米糠-耐Pb菌株复合吸附剂固定床穿透曲线特性

发布时间：2018-05-03 17:27

本文选题：粟米糠 + 米曲霉　；参考：《环境科学学报》2017年07期

【摘要】：以粟米糠(MC)为原料,添加自铅锌尾矿渣中分离的耐铅菌米曲霉(HA)制成粟米糠-耐Pb菌株复合吸附剂(MCH),研究固定床系统中MCH对Pb~(2+)的动态吸附特性,考察吸附柱高度、初始离子浓度、进水流速对穿透曲线特性的影响.研究结果表明,复合吸附剂在固定床系统中的吸附性能明显优于单一吸附剂;MCH对Pb~(2+)的吸附穿透时间与吸附柱高成正相关,与初始离子浓度和进水流速成负相关,传质区长度与吸附柱高成负相关,与初始离子浓度和进水流速成正相关;初始离子浓度对穿透曲线和传质区长度影响最小.采用BDST、Yoon-Nelson和Thomas模型拟合试验数据结果显示,在较高流速和初始离子浓度条件下,实测与BDST模型拟合数据的相对误差最小,其原因可解释为BDST模型忽略了内部扩散和质量传递间阻力的影响;在吸附柱较低、初始离子浓度或进水流速较大条件下,由于传质推动力过大以至传质区被瞬间穿透,吸附质在吸附柱内停留时间很短,Yoon-Nelson和Thomas模型无法准确预测其穿透时间和拟合穿透曲线;总体上对比其它模型,Thomas模型拟合穿透曲线的效果较好,说明在MCH固定床Pb~(2+)的吸附过程中没有轴向扩散且具有平推流作用.
[Abstract]:The dynamic adsorption characteristics of MCH for Pb~(2 in fixed bed system were studied by adding lead resistant fungi (Aspergillus oryzae) isolated from lead-zinc tailings as raw materials to the composite adsorbent of millet bran and Pb resistant strain. The influence of initial ion concentration and influent velocity on the characteristic of penetration curve. The results show that the adsorption performance of the composite adsorbent in the fixed bed system is obviously better than that of the single adsorbent Pb~(2. The adsorption penetration time of the composite adsorbent is positively correlated with the high adsorption column formation, and is negatively correlated with the initial ion concentration and the velocity of inlet flow. The length of the mass transfer zone is negatively correlated with the adsorption column Gao Cheng, and is positively correlated with the initial ion concentration and the velocity of the inlet current, and the initial ion concentration has the least effect on the penetration curve and the length of the mass transfer zone. The experimental data were fitted with the Thomas model and Yoon-Nelson model. The results showed that the relative error between the measured data and the BDST model was the least under the condition of high velocity of flow and initial ion concentration. The reason can be explained by the fact that the BDST model neglects the influence of the resistance between internal diffusion and mass transfer. Under the condition of lower adsorption column, higher initial ion concentration or higher influent velocity, the mass transfer zone is penetrated instantly because the mass transfer force is too large. The retention time of adsorbate in the adsorption column is very short. Yoon-Nelson and Thomas models can not accurately predict the penetration time and fit the penetration curve. The results show that there is no axial diffusion in the adsorption process of MCH fixed bed Pb~(2.
【作者单位】：中南林业科技大学环境科学与工程研究所;
【基金】：国家“十二五”科技惠民计划项目(No.2012GS430203) 国家“十二五”科技支撑计划项目(No.2012BAC09B03) 湖南省环境科学与工程重点学科建设项目资助~~
【分类号】：O647.33;X703;X712

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