【摘要】 [目的]通过改性对硅藻土表面修饰与结构优化，有效提高硅藻土的吸附性能，为重金属污染土壤修复提供技术支撑。[方法]以原始硅藻土为原材料，用Mg（OH）₂、MnCl₂制备改性硅藻土（G-DIA、N-DIA）,分析改性处理后硅藻土的特征，解析初始溶液浓度、pH、时间等对Pb²⁺、Zn²⁺吸附特性的影响。[结果]改性后的硅藻土呈现不规则颗粒团聚体，晶体结构发生显著变化，出现了新的—OH、Si—OH等官能团，表面变得粗糙多孔，比表面积大幅度增加，提供大量吸附位点。G-DIA和N-DIA土壤对溶液中Pb²⁺、Zn²⁺的吸附量受初始溶液的浓度、pH、吸附时间、硅藻土用量等因素的影响。改性硅藻土土壤对溶液中Pb²⁺、Zn²⁺的吸附量均随初始溶液pH的增加而不断上升；溶液中Pb²⁺、Zn²⁺的去除率随硅藻土添加量的增加呈上升趋势，吸附量则呈现下降趋势。G-DIA对Pb²⁺、Zn²⁺的吸附以多分子层吸附和物理吸附为主，符合Freundlich模型和准一级动力学模型；N-DIA对Pb²⁺的吸附以单层化学吸附为主，对Zn²⁺的吸附以多分子层吸附为主，符合准二级动力学模型。在铅锌二元体系中，Pb²⁺、Zn²⁺以竞争关系为主，Pb²⁺对Zn²⁺的抑制作用大于Zn²⁺对Pb²⁺的抑制作用。[结论]在铅锌复合污染土壤中施入改性硅藻土能有效降低Pb、Zn活力，可作为铅锌污染土壤修复的有效材料。更多还原

【Abstract】 [Objective] Surface modification and structural optimization of diatomite can effectively enhance its adsorption performance, thereby providing technical support for the remediation of heavy metal-contaminated soils. [Method] Raw diatomite was employed as the starting material to synthesize two modified diatomites, including G-DIA [Mg（OH）₂-modified] and N-DIA（MnCl₂-modified）. The physicochemical characteristics of the modified materials were systematically characterized. Subsequently, the effects of key operational parameters, including initial metal ion concentration, solution pH, contact time, and diatomite dosage, on the adsorption of Pb²⁺ and Zn²⁺were investigated. [Result] The modified diatomites exhibited irregular particle aggregates with pronounced alterations in crystalline structure. New functional groups, including hydroxyl（-OH） and silanol（Si-OH） groups emerged on their surfaces, which became notably rougher and more porous. Concurrently, their specific surface area increased substantially, generating abundant active adsorption sites. The adsorption capacities of G-DIA and N-DIA for Pb²⁺ and Zn²⁺were significantly influenced by initial solution concentration, pH, contact time, and adsorbent dosage. Adsorption capacity for both Pb²⁺ and Zn²⁺increased progressively with rising initial solution pH. While removal efficiency of Pb²⁺ and Zn²⁺improved with increasing diatomite dosage, the corresponding adsorption capacity（i.e., uptake per unit mass of adsorbent） declined. Adsorption of Pb²⁺ and Zn²⁺onto G-DIA was predominantly multilayer and physical in nature, well described by the Freundlich isotherm and pseudo-first-order kinetic model. In contrast, Pb²⁺ adsorption onto N-DIA was primarily monolayer and chemisorptive, whereas Zn²⁺adsorption followed a multilayer mechanism; both processes were best fitted by the pseudo-second-order kinetic model. In the binary Pb²⁺-Zn²⁺system, competitive adsorption occurred, with Pb²⁺ exerting a stronger inhibitory effect on Zn²⁺adsorption than vice versa. [Conclusion] The application of modified diatomite in lead-zinc composite contaminated soil can effectively reduce the activities of Pb and Zn, and can be used as an effective material for the remediation of lead-zinc contaminated soil.更多还原