• 关键词：锰氧化物  锌吸附  水钠锰矿  铅吸附  八面体空穴

• 基金项目：国家自然科学基金项目(No.40771102);全国优秀博士学位论文作者专项资金资助项目(No.200767);湖北省自然科学基金计划青年杰出人才项目(No.2007ABB014)

• 赵巍
• 华中农业大学农业部亚热带农业资源与环境重点开放实验室, 武汉 430070

• 王庆庆
• 华中农业大学农业部亚热带农业资源与环境重点开放实验室, 武汉 430070

• 刘凡
• 华中农业大学农业部亚热带农业资源与环境重点开放实验室, 武汉 430070

• 邱国红
• 华中农业大学农业部亚热带农业资源与环境重点开放实验室, 武汉 430070

• 谭文峰
• 华中农业大学农业部亚热带农业资源与环境重点开放实验室, 武汉 430070

• 冯雄汉
• 华中农业大学农业部亚热带农业资源与环境重点开放实验室, 武汉 430070

• 摘要：分别采用Zn²⁺和Mn²⁺处理锰平均氧化度较高的水钠锰矿,对比研究了经不同浓度的Zn²⁺和Mn²⁺处理后矿物的锰平均氧化度、d₁₁₀面网间距、对Pb²⁺的最大吸附量以及吸附过程中Zn²⁺和Mn²⁺的最大释放量等的变化.同时,通过Zn²⁺和Mn²⁺与水钠锰矿表面反应行为的不同,

• Abstract：The Pb²⁺ adsorption behavior of birnessite with high Mn average oxidation state (AOS) before and after treatment by preadsorption of Zn²⁺ and Mn²⁺ was compared. The association of vacant Mn octahedral sites with Pb²⁺ adsorption was determined from the AOS,d(110)-interplanar spacing,maximum Pb²⁺ adsorption,and maximum Zn²⁺ and Mn²⁺ release during Pb²⁺ adsorption by the birnessites before and after treatment. The AOS and d(110)-interplanar spacing of the birnessites remained almost unchanged as the concentration of Zn²⁺ increased,indicative of an unchanged number of vacant Mn octahedral sites. Maximum Pb²⁺ adsorption decreased from 3190 to 2030 mmol·kg^-1 due to Zn²⁺ occupancy of the adsorption sites. When the concentration of Mn²⁺ in the pretreatment increased from 1 to 2.4 mmol·L^-1,the AOS of the birnessites decreased,and most of the Mn²⁺ was oxidized to Mn³⁺ located above or below vacant Mn octahedral sites or migrated into vacant Mn octahedral sites. The d(110)-interplanar spacings of the treated birnessites increased from 0.14160 to 0.14196 nm,indicative of a decrease in the number of vacant Mn octahedral sites,mainly due to the produced Mn³⁺ migrating into vacant Mn octahedral sites. Moreover,the maximum Pb²⁺ adsorption of the Mn²⁺-treated birnessites was observed to decrease from 3190 to 1332 mmol·kg^-1. The results suggest that birnessite Pb²⁺ adsorption capacity is largely determined by the number of Mn site vacancies.

• Key words：Zn²⁺ adsorption  birnessite  Pb²⁺ adsorption  vacant Mn octahedral site

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