载铁膜沸石制备及其控制河道污染物的试验研究

发布时间：2018-04-24 23:35

本文选题：污染底泥 + 覆盖　；参考：《哈尔滨工业大学》2015年硕士论文

【摘要】：污染底泥是河道主要污染源之一,随着外源污染的有效控制和河道水体治理的推进,污染底泥引起的内源污染问题日益突出,亟需对河道底泥污染物的释放予以控制。在多种河道底泥污染治理技术中,由于底泥原位覆盖技术对环境造成扰动小、处理见效快、效果好而得到广泛关注和应用。然而,现有的单一覆层或混合覆层的覆盖材料存在不可同步抑制多种污染物释放的缺点,限制了其适用范围。本研究提出通过对沸石进行载铁制备复合覆盖材料的思路,以解决传统单一覆层或混合覆层材料所存在问题。本文通过对沸石载铁铁源、负载方法、负载次数进行优选,得到优选的载铁膜沸石(Iron Oxide Coated Zeolite,IOCZ)制备条件,并对制备成品进行表征;其后,考察了优选所得IOCZ处理污染物性能和常见共存物质对其处理性能的影响,并初步探究了处理污染物机制;进行柱实验模拟IOCZ覆层控制底泥污染物释放场景以为其实际应用提供数据支持,并考察所处理污染物存在IOCZ中稳定性。通过研究得到,以氯化铁为铁源,铁泥涂布为负载方法,负载一次所得载铁膜沸石载铁量、载铁稳定性和处理以氨氮磷酸盐为典型阴阳离子污染物效果最佳。载铁后,沸石密度未发生变化;比表面积略有增加;表面新增Fe-OH、Fe-O官能团;沸石所载氧化铁晶体为Fe OOH和Fe2O3;IOCZ零电位点位于p H8.5左右。与原沸石相比,IOCZ增加对磷酸盐、硫化物及六价铬的去除效果,对氨氮及Cu、Zn、Pb的去除效果略有下降。混合溶液中,氨氮对IOCZ去除磷酸盐和硫化物无影响,硫化物对磷酸盐的去除有抑制作用。常见共存物质中,天然有机物对IOCZ处理氨氮的速率略有减缓作用,Cl-、硅酸根对其无影响;天然有机物对IOCZ处理磷酸盐略有抑制作用,Cl-未造成影响,硅酸根离子使IOCZ处理磷酸盐的处理容量和处理速率均有所下降;三者对处理硫化物均无明显影响。IOCZ作用机制初步探究表明:IOCZ去除氨氮为静电吸附作用;处理磷酸盐为络合吸附机制;处理硫化物为氧化还原反应和吸附共同作用。柱实验结果表明:IOCZ可有效抑制底部污染物的释放,所处理污染物总量与覆层厚度之间存在相关比例系数,且已处理污染物可稳定存在于IOCZ中。
[Abstract]:Polluted sediment is one of the main pollution sources in river. With the effective control of exogenous pollution and the improvement of river water treatment, the problem of internal pollution caused by polluted sediment is becoming more and more serious, and it is urgent to control the release of pollutants from river sediment. In many kinds of river channel sediment pollution treatment technology, because the sediment in-situ covering technology has little disturbance to the environment, the treatment effect is quick, the effect is good, so it has been widely paid attention to and applied. However, the existing single or mixed coating materials have the disadvantage of not synchronously inhibiting the release of many pollutants, which limits their application scope. In order to solve the problems existing in traditional single or mixed coating materials, the idea of preparing composite covering materials by carrying iron on zeolites was put forward in this study. In this paper, the preparation conditions of Fe carrying membrane zeolite Iron Oxide Coated Zeolite IOCZs were obtained by the optimum selection of Fe carrying iron Tie Yuan, loading method and loading times, and the final product was characterized. The effects of excellent selected IOCZ on the treatment performance of pollutants and common co-existing substances were investigated, and the mechanism of pollutant treatment was preliminarily explored. Column experiments were carried out to simulate the release scene of pollutants from sediment controlled by IOCZ coating, which provided data support for its practical application, and the stability of pollutants in IOCZ was investigated. The results showed that the best results were obtained by using ferric chloride as Tie Yuan and iron slime coating as loading method. The results showed that the amount of iron loaded with ferric membrane zeolite, the stability of iron carrier and the treatment of anion and anion pollutants with ammonia nitrogen phosphate as typical ion were the best. After iron loading, the density of zeolites did not change, the specific surface area increased slightly, Fe-O functional groups were added on the surface, and the zero potential points of Fe OOH and Fe 2O 3 IOCZ were found to be about pH 8.5. Compared with the original zeolite, IOCZ increased the removal efficiency of phosphate, sulfides and hexavalent chromium, and slightly decreased the removal efficiency of ammonia nitrogen and Cu ~ (2 +) Zn ~ (+ +) Pb. Ammonia nitrogen has no effect on the removal of phosphate and sulfides by IOCZ, while sulfides inhibit the removal of phosphate in mixed solution. Among the common co-existing substances, natural organic compounds have a slight decrease in the rate of ammonia-nitrogen treatment by IOCZ, but silicates have no effect on them, and natural organic compounds have no effect on the inhibition of phosphate treatment by IOCZ. The treatment capacity and treatment rate of phosphate treated with IOCZ were decreased by silicate ion, and the mechanism of removal of ammonia nitrogen by IOCZ was electrostatic adsorption, which had no obvious effect on the treatment of sulfides. Phosphate treatment is a complex adsorption mechanism, and sulfide treatment is redox reaction and adsorption. The results of column experiments show that the release of pollutants from the bottom can be effectively inhibited by the solution. There is a correlation coefficient between the total amount of pollutants treated and the thickness of the coating, and the treated pollutants can exist stably in IOCZ.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X52

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