水体除砷材料的筛选及其化学成分特征研究

SELECTION OF MATERIAL FOR ARSENIC REMOVAL AND RESEARCH ON THE CHARACTERISTIC OF CHMICAL COMPOSITION

为筛选适合于水体除砷的材料,比较研究了26种不同材料对水体砷的去除效果及其矿物元素含量。研究结果表明,采用水与矿物质量比为100、砷的质量浓度0.200 mg·L-1、震荡时间1 h条件下,纳米二氧化钛类矿物对水体As(V)和As(III)去除率达90%以上,效果最好;其次是活性氧化铝和宜昌锰矿粉,去除率在80%～90%;而最差的是斜发沸石和金红石,去除率低于40%。一些矿物含有污染元素,如铁矿渣和铁精粉(初)中砷的质量分数分别达到478和202μg·g-1,远高于其他矿物。铜含量最高的矿物是宜昌锰矿粉、铁矿渣、铁精粉(初)(Cu的质量分数分别为7460、2 884、3 378μg·g-1);铁矿渣的锌含量(质量分数28 030μg·g-1)最高。同一类型的矿物元素含量差异显著,如VK-T01二氧化钛中砷的质量分数高达91μg·g-1,而VK-T25H二氧化钛、VK-TA18H二氧化钛和P25二氧化钛砷的质量分数仅3～6μg·g-1;膨润土ZJL中砷、钾、钠、锌的含量远高于膨润土原矿1 6pu红和膨润土原矿1 6pu白。结果说明,矿物除砷效果和污染元素含量差别很大,应根据实际测定结果谨慎选用。

Selection of appropriate materials for arsenic removal from water is of great significance.In order to obtain materials of high efficiency and great safety,a comparative study was carried out to study the As-removal efficacy from As-spiked water by 26 kinds of materials and their characteristics of chemical element composition.The results showed that,under the experimental condition of mineral： water ratio of 100,As concentration of 0.200 mg·L^-1,and shaking time of 1h,minerals of nano-titanium dioxide removed 〉90% of spiked As（V） and As（III）,followed by Activated alumina and Yichang manganese ore,with the removal efficiency of 80%～90%,and clinoptilolite and rutile ore removed 〈40% of As,being the worst for As removal.Some materials contained polluted elements.Iron slag and Primary iron powder contained 478 and 202 μg·g^-1 of As,being the highest among 26 materials.Threeminerals with high Cu contents were Yichang manganese ore（7 460 μg·g^-1）,Iron slag（3 378 μg·g^-1） and Primary iron powder（2 884 μg·g^-1）.In addition,Iron slag had the highest Zinc concentrations of 28 030 μg·g^-1.The same type of minerals could contain variable concentrations of the same element.Forinstances,As contents in VK-T01 titanium dioxide was 91 μg·g^-1,while it was only 3～6 μg·g^-1 in VK-T25H titanium dioxide,VK-TA18H titanium dioxideand P25 titanium dioxide;and the content of arsenic,potassium,sodium,zinc in bentonite ZJL ore was much higher than that in bentonite 1 6 pu redand bentonite 1 6pu white.These results suggested that there were great difference of As-removal efficiency and contents of polluted elements among materials,and materials for As removal should be carefully selected after a practical analysis.