复合污染对Pb2+在固定床系统中的动态吸附过程影响及机制

针对复合污染体系对污染物处理效果的影响问题，以限氧裂解法制备的污泥基生物炭（SSB）为吸附剂，探索其在不同污染体系下的吸附性能变化.基于污泥基生物炭构建固定床系统，研究连续流条件下复合污染体系（Zn2+、NH₄+、H₂PO₄-）对Pb2+在固定床动态吸附行为的影响，对比不同体系下系统运行参数的变化.结果表明:①不同复合体系均对SSB的Pb2+吸附效果产生抑制作用，其影响大小为NH₄+ > Zn2+ > H₂PO₄-.而三元/四元复合污染体系中，H₂PO₄-的加入会减弱复杂体系对Pb2+的吸附抑制作用.②固定床系统中，不同复合体系对吸附穿透曲线参数的影响顺序为Pb2+-Zn2+-NH₄+-H₂PO₄- > Pb2+-Zn2+-H₂PO₄- > Pb2+-Zn2+-NH₄+ > Pb2+-NH₄+-H₂PO₄-.③固定床系统动态吸附量（q_d）与传质区长度（H）的变化分析均显示，复合污染体系会降低固定床吸附性能.④数据拟合结果表明，相比于Yoon-Nelson模型，Thomas模型能更好地描述Pb2+在复合体系中的动态吸附过程，但复合污染会限制动态吸附模型的应用，导致模型预测不准确.研究显示，复合污染体系会显著影响吸附剂在连续流状态下的吸附性能，有选择地处理特定污染物可以减少复合污染体系对净化效果的干扰. 

Effect of Complex Contaminants on Dynamic Adsorption Behaviors of Pb2+ in Fixed-Bed System: Breakthrough Curve Characteristics and Parameters

Sludge-based biochar (SBB) was prepared and used to construct a fixed-bed system to determine the effect of complex systems on the performance of the adsorbent in continuous flow. The effects of different contaminants (Zn²⁺, NH₄⁺, H₂PO₄^-) on Pb²⁺ adsorption in continuous flow were studied, and fixed-bed parameters were calculated. The results indicated that in the binary-component systems, the inhibition effect of the three contaminants on Pb²⁺ adsorption followed the order of NH₄⁺ > Zn²⁺ > H₂PO₄^-. When H₂PO₄^- existed in the ternary or quaternary systems, it decreased the inhibition effect of the other contaminants on Pb²⁺ adsorption. Meanwhile, Zn²⁺ showed more significant effect on the breakthrough curves than all other contaminant combinations. The influence of different systems on the parameters of breakthrough curves followed the order of Pb²⁺-Zn²⁺-NH₄⁺-H₂PO₄^- > Pb²⁺-Zn²⁺-H₂PO₄^- > Pb²⁺-Zn²⁺-NH₄⁺ > Pb²⁺-NH₄⁺-H₂PO₄^-. The changes of the dynamic adsorption capacity (q_d) and height of mass transfer zone (H) indicated that the complex system resulted in the degradation of fixed-bed adsorption performance. Additionally, compared with the Yoon-Nelson model, the Thomas model could better describe the Pb²⁺ adsorption process in the fixed-bed system. The application of the model was restricted by the complex environmental pollutants, and the interaction effect between the adsorbates hindered the prediction performance of the model for fixed-bed. In conclusion, the complex system significantly affects the adsorption performance of the adsorbent, and more attention should be paid to the treatment of wastewater with complex contaminants.