不同晶型锰氧化物去除地下水中氨的效能与机理  

Efficiency and mechanism of removing ammonium from groundwater by manganese oxides with different crystal forms

作　　者：程亚 苗安琪 黄廷林 文刚 CHENG Ya;MIAO An-qi;HUANG Ting-lin;WEN Gang(Shaanxi Key Laboratory of Environmental Engineering,Key Laboratory of Northwest Water Resource,Ministry of Education,Collaborative Innovation Center of Water Pollution Control and Water Quality Security Assurance of Shaanxi Province,School of Environment and Municipal Engineering,Xi'an University of Architecture and Technology,Xi'an 710055,China)

机构地区：[1]西安建筑科技大学环境与市政工程学院,陕西省环境工程重点实验室,西北水资源与环境生态教育部重点实验室,陕西省水污染控制与水质安全保障协同创新中心,陕西西安710055

出　　处：《中国环境科学》2024年第9期4978-4986,共9页China Environmental Science

基　　金：国家自然科学基金(52000145);陕西省重点科技创新团队项目(2023-CX-TD-32);陕西省教育厅重点科学研究计划项目(22JY035);陕西省高校科协青年人才托举计划项目(20230447)。

摘　　要：研究了3种不同晶型二氧化锰(α-MnO_(2)、γ-MnO_(2)、δ-MnO_(2))去除地下水中氨的效能与机理,并考察了负载γ-MnO_(2)滤料填充滤柱实际应用效果.结果表明,γ-MnO_(2)催化氧化除氨效果最优(γ-MnO_(2)>α-MnO_(2)>δ-MnO_(2)),第20d 5mg/L氨可以被完全去除,且其中间产物亚硝酸盐氮的积累时间最短,峰值最低.γ-MnO_(2)负载滤料填充滤柱可以快速(第6d)具备优异的催化除氨能力,当进水氨为2.0mg/L时,出水氨低于标准限值(<0.5mg/L).结合材料表征分析结果发现,γ-MnO_(2)具备最优的催化氧化除氨能力主要是由于其较高的锰平均氧化态与其丰富的表面羟基氧,其电子传递能力最强.本研究为锰氧化物在饮用水除氨领域的应用提供了理论指导,γ-MnO_(2)负载滤料具有良好的催化氧化除氨稳定性和效能,为实际工程中催化氧化活性滤料的制备提供了新思路.The efficiency and mechanism of removing ammonium from groundwater by manganese dioxide with three different crystal forms (α-MnO_(2),γ-MnO_(2),δ-MnO_(2)) were studied,and the practical application efficiency of the filter column filled withγ-MnO_(2) coated filter media was investigated.The experimental results showed that γ-MnO_(2) possessed the best catalytic oxidation activity for removing ammonium (γ-MnO_(2)>α-MnO_(2)>δ-MnO_(2)),5mg/L NH_(4)^(+)-N could be completely removed on the 20^(th) day,and the accumulation time of nitrite was the shortest and the peak value was the lowest.The filter column filled with γ-MnO_(2) coated filter media could quickly (the 6^(th) day) form excellent catalytic activity,when the influent NH_(4)^(+)-N was 2.0mg/L,the effluent NH_(4)^(+)-N was lower than the standard limit (<0.5mg/L).Combined with the characterization analysis,it was found that the highest catalytic activity of γ-MnO_(2) was mainly due to its higher average manganese oxidation state and abundant surface hydroxy oxygen,and its electron transport ability was the strongest.This study provides theoretical guidance for the application of manganese oxides in the field of ammonium removal from drinking water.γ-MnO_(2) coated filter media has good catalytic oxidation stability and efficiency,and provides a new perspective for the preparation of catalytic oxidation active filter media in practical engineering.

关 键 词：晶型 锰氧化物 氨 催化氧化 地下水 

分 类 号：X523[环境科学与工程—环境工程]