【作者】 李杰；

【导师】 李金成；

【作者基本信息】 青岛理工大学 ， 环境工程， 2010， 硕士

【摘要】 针对地下水砷污染日趋严重的问题,制备了铁氧化物改性滤料和锰氧化物改性滤料并对其表面性质进行了表征;研究了改性滤料的吸附除As（Ⅲ）效果、除As（Ⅲ）动力学、pH、共存离子对除As（Ⅲ）效果的影响;对改性滤料的再生进行了研究,并对改性滤料的改性机理及吸附除As（Ⅲ）机理进行了初步探讨。主要结论如下:（1）采用铁盐溶液蒸发法制备了铁氧化物改性滤料,其表面铁氧化物的负载量为5.604mgFe/g,表面铁氧化物的抗酸碱性能较好、负载强度较高;经测定该滤料的等电点约为8.25;分别以活性炭和石英砂为载体制备了锰氧化物改性滤料,前者表面的锰氧化物负载量及负载强度均好于后者;石英砂滤料经锰氧化物改性后对As（Ⅲ）的去除效果变化不大,而活性炭滤料经改性后对As（Ⅲ）的去除效果明显提高。（2）100ml初始As（Ⅲ）浓度为0.5mg/L的溶液中,铁氧化物改性滤料的最佳投加量为2.5g,锰氧化物改性活性炭滤料的最佳投加量为1.0g。两种改性滤料对As（Ⅲ）吸附动力学均符合Lagergren二级吸附动力学模型,其吸附等温式可用Langmuir吸附等温式来描述,但锰氧化物改性滤料的吸附除As（Ⅲ）速率较快。（3）pH在4.0⁸.0的范围内,铁氧化物改性滤料对As（Ⅲ）的去除率较高,保持在85%以上;对于锰氧化物改性活性炭滤料,pH<7.7时,As（Ⅲ）的吸附量随pH值升高变化不大;pH>7.7时,随pH值的升高,As（Ⅲ）的去除率迅速下降。磷酸盐和硫酸盐的存在,对两种滤料吸附除As（Ⅲ）均有抑制作用,但硫酸盐比磷酸盐的抑制作用要小的多。（4）选用0.1mol/L的NaOH对铁氧化物改性滤料进行再生,再生率较高,再生速度也较快;新制备的铁氧化物改性滤料对As（Ⅲ）的去除率可达90.8%,再生次数对As（Ⅲ）的去除效果影响不大;柱实验表明:滤速应控制在6m/h以下;进水硬度越大,As（Ⅲ）的去除率越低;采用0.1mol/L的NaOH溶液对吸附柱进行再生,滤料再生后的吸附除As（Ⅲ）效果有所降低,但再生次数对除As（Ⅲ）效果影响不大。（5）锰氧化物改性活性炭滤料对As（Ⅲ）和As（V）的去除效果相当,但在除As（Ⅲ）时,溶液中有大量的锰溶出,而除As（V）时,锰的溶出量很小。这表明在As（Ⅲ）的吸附体系中同时存在氧化还原作用,去除As（Ⅲ）过程中,会有Mn²⁺的释放。（6）通过对两种滤料进行比较得出:铁氧化物改性滤料除As（Ⅲ）效果好,不会造成二次污染,不需要预氧化且再生后可重复利用,节约了经济成本,适合用于各类含砷饮用水的净化;锰氧化物改性活性碳滤料,成本较高,且在吸附As（Ⅲ）过程中有锰的溶出,用该滤料去除As（Ⅲ）,应先将其氧化为As（V）,该滤料在去除As（V）时,表现出去除效果好、吸附速率快的优点。更多还原

【Abstract】 In allusion to the problem of the contamination of arsenic growing in groundwater, prepared iron oxide modified filter media and manganese oxides modified filter media and characterized its surface properties; Studaied of the effect of adsorption As（Ⅲ）、the kinetics of removal of As（Ⅲ）, the effect of pH and coexisting ions using modified materials; The regeneration of the modified materials were studied and the modification mechanism and the modified materials adsorption of As（Ⅲ）process were discussed. The main conclusions are as follows:（1） Prepared iron oxide modified filter media using iron salt solution evaporation, the iron oxide content of surface is 5.604mgFe/g, the anti-acid-base propertie and adhesion strength are perfect; The determination of the isoelectric point is about 8.25; Respectively, using activated carbon and quartz sand as the carrier prepared manganese oxide modified materials, the former attached to the surface of the amount of manganese oxide and the adhesion strength are better than the latter; The effect of removal of As（Ⅲ） changed little beforeand after the Quartz sand modified by manganese oxides, but modified activated carbon filter was significantly improved.（2）When the initial As（Ⅲ） concentration is 0.5mg/Land volume is 100ml, the best dosage of iron oxides modified filter media is 2.5g and for manganese oxide modified activated carbon filter is 1.0g. The kinetics of removal of As（Ⅲ） are in line with Lagergren adsorption kinetic model II and the adsorption isotherm Langmuir isotherm can be used to describefor the two modified materials, but the adsorption rate of manganese oxide modified filter media was faster.（3） The rate of removal of As（Ⅲ） is higher than 85% using iron oxide modified filter media, when pH in the range of 4.0 to 8.0; For the manganese oxide modified activated carbon filter media.When pH <7.7, the adsorption of As（Ⅲ） changed little with the increasing of pH; When pH> 7.7, with the increased of pH, the removal rate of As （Ⅲ） decreased rapidly. The presence of phosphate and sulfate, had inhibited the removal of As （Ⅲ）for the two modified materials, but the inhibitory effect of phosphate sulfate is smaller than the sulphate. （4） Selecting of 0.1mol/L of NaOH to regenerated of iron oxide modified filter media, regeneration ratewas high and regeneration speed was rapid; The removal rate of As （Ⅲ） reach to 90.8% with freshly iron oxide modified filter media, regeneration times has little effect on removal of As（Ⅲ）; Column experiments show that: the filtration rate should be controlled at 6m/h below; The greater of water hardness, the lower rateof removal of As（Ⅲ）; Using 0.1mol/L of NaOH solution to regenerated the adsorption column, after regenerated, the effects of adsorption of As（Ⅲ） were reduced, but the number of regeneration has little effect for therenoval of As（Ⅲ）.（5） Manganese oxide modified activated carbon filter media had considerable removal efficiency of As（Ⅲ） and As（V）, but in addition to As（Ⅲ）, a large number of manganese dissolved in the solution, subject to As（V）, a small amount of manganese dissolved. This indicated that, existed redox in As（Ⅲ） adsorption system.When remove of As （Ⅲ）,there will be the release of Mn²⁺.（6） By comparing the two modified materials obtained that:iron oxide modified filter media canremoval of As（Ⅲ） effectly, and will not cause secondary pollution, no pre-oxidation and can be reused after regeneration, saving the economy cost, suitable for various types of arsenic in drinking water purification; Manganese oxide modified activated carbon filter had high cost, and in the process of adsorption of As（Ⅲ） had manganese dissolved, Using the filter to remove of As（Ⅲ）, should be oxidated to As （V） firstly, When removal ofwith the media,the effect of removal of As（V） is perfect, adsorption rate was fast.更多还原