摘要
利用溶液法和固态合成法制备α、β、γ和δ晶型粉末二氧化锰,借助等电点测定技术、颗粒计数仪、傅立叶-红外光谱、X射线衍射光谱和原子力显微镜对其性质进行了表征;并通过静态吸附平衡实验考察了上述物质对水溶液中阳离子染料亚甲基蓝的去除效能.结果表明,δ二氧化锰去除染料的能力相对最强,试验条件下染料去除率达99.0%,脱色能力受pH变化的影响也最小;其脱色机理可能是染料中的N原子与二氧化锰表面羟基形成的氢键作用,以及静电吸引的叠加,其中氢键去除占主导地位.其它晶型的二氧化锰只在强酸性时存在表面羟基;故只在强酸性时有良好的脱色能力.pH值是影响去除染料能力的关键因素,脱色能力随pH值的变化规律因晶型而异,体系温度和颗粒分布也对去除能力有一定影响.
Manganese dioxide with crystal structures of α、β、γ and δ was prepared successfully by solution and solid state reaction and characterized by pHspc measurement, particle distribution instrument, FT-IR spectrum, XBD and AFM. The removal of a cationic dye, methylene blue, from aqueous solutions by adsorption onto manganese dioxide is investigated using batch experiments. It is found that δ manganese dioxide has the strongest ability for removal among the materials and it has the most stable removal ability according to the change of pH, the dye removal efficiency was 99.0% under the experimental conditions. The dominant probable mechanism of the process is the combination of hydrogen bonding between nitrogen atoms of methylene blue and hydroxyl groups on the manganese dioxide surface, electrostatic interactions also play a role in the removal process. Manganese dioxide with other crystal structures only has surface hydroxyl groups under strong acidic condition, this make them high removal efficiency only in these conditions. The pH value is the key factor for dye removal. The change of color removal efficiency caused by pH value is related to the crystal structure. The system temperature and particle distribution of manganese dioxide also affect the dye removal efficiency.
出处
《环境科学学报》
CAS
CSCD
北大核心
2006年第12期1971-1976,共6页
Acta Scientiae Circumstantiae
基金
黑龙江省博士后科学基金~~
关键词
二氧化锰
晶型
阳离子染料
亚甲基蓝
吸附
氢健
印染废水
脱色
manganese dioxide
crystal structure
cationic dye
methylene blue
adsorption
hydrogen bonding
dye wastewater
decolorization
