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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.
In this study, corn bran (MC) was used as raw material, and lead-tolerant Aspergillus oryzae (HA) was isolated from lead-zinc tailings residue to make corn bran-Pb tolerant composite sorbent (MCH) (2 +), and the effect of adsorption column height, initial ion concentration and influent flow rate on the penetration curve was investigated.The results show that the adsorption performance of composite adsorbent in fixed bed system is obviously better than that of single adsorbent ; The adsorption breakthrough time of MCH for Pb 2+ is positively related to the height of the adsorption column and negatively related to the initial ion concentration and the flow rate of the influent. The length of the mass transfer region is negatively correlated with the height of the adsorption column, The initial ion concentration has the least effect on the breakthrough curve and the mass transfer zone length.Based on the BDST, Yoon-Nelson and Thomas model fitting test data, the experimental results show that at high flow rate and initial ion concentration, The reason for the smallest relative error of the model fitting data is that the BDST model ignores the influence of internal diffusion and mass transfer resistance. Under the condition of low adsorption column, initial ion concentration or inflow velocity, Too great The mass transfer zone was instantly penetrated and the adsorbate stayed in the adsorption column for a short time. The Yoon-Nelson and Thomas models were unable to accurately predict the breakthrough time and the fitting breakthrough curve. In general, compared with other models, the Thomas model fitting fitted The effect of the transparent curve is better, which shows that there is no axial diffusion and thrust flow in the adsorption process of Pb ~ (2+) on the fixed bed of MCH.