Functionalized Adsorbents For The Removal Of Heavy Metal Ions In Water And Analytical Application

Functionalized adsorbents of the thesis were prepared by activated carbon, with the aid of a calcium solution extracted from egg shell wastes and phosphoric acid, Fe3O4and gum arabic as activating agents. Functionalized adsorbents are Ca2+/PO43--modified activated carbon, Fe3O4-loaded activated carbon, and gum Arabic-modified magnetic carbon. On the one hand, the author studies the characteristics of functionalized adsorbents, and its adsorbent effect to heavy metals in drinking water of secondary pollution. On the other hand, the author uses magnetic absorbents:Fe3O4-loaded activated carbon and gum Arabic-modified magnetic carbon to enrich trace arsenic and copper in drinking water, and then measure trace these two ions by anodic stripping voltammetry. The results of this thesis can be summarized as following:(1) A calcium solution extracted from egg shell wastes can be used as a low-cost activation agent to improve the adsorption properties. At26癈and pH6.8, Ca2+/PO43-modified activated carbon is to deal with As(Ⅲ)、 Cd2+、Pb2+、Cr(Ⅵ)in drinking water. The result shows that Ca2+/PO43-modified activated carbon using an adsorbent dosage of1g/L, suspending adsorb2hours, could remove2.5times the limited amounts of Cd2+、Pb2+、Cr(Ⅵ) in Standards for Drinking Water Quality, and the original amounts of Cu2+、Zn2+、Al+are lower in drinking water.(2) At26℃and pH6.8in drinking water, gum Arabic-modified magnetic carbon is to remove copper ion from the drinking water. The result shows that its adsorption equilibrium can be achieved within5minutes, and the maximum adsorption capacity is39.05mg/g.Also, adsorption data obeys the Freundlich isotherm equation, and the Freundlich adsorption constant is1.260L/mg.(3) At26℃and pH6.8in drinking water, functionalize-d adsorbents can make up for deficiency of a single adsorbent, for it can remove As(Ⅲ)、Cd2+、Cr(Ⅵ)、Pb2+heavy metals in drinking water. From this experiment, two results can be obtained. First, after0.9g/L functionalized adsorbents have been suspended for6hours, it can remove1.25times’the limited amounts of As(Ⅲ)、Cd2+、Pb2+、Cr(Ⅵ) in Standards for Drinking Water Quality. Second, the original amounts of Cu2+、Zn2+、Al3+reduce in drinking water.(4) The magnetic adsorbent, as adsorbents of enrichment, enrich traces of arsenic and copper, to increase the sensitivity of the determination arsenic and copper in drinking water. First, magnetic carbon enrich arsenic, then use gold electrode anodic stripping voltammetry to measure trace arsenic in drinking water. The result shows that the relative standard deviation (RSD) is0.1%～0.8%. Gum Arabic-modified magnetic carbon is to enrich copper, which is then measured by anodic stripping voltammetry. In this experiment, relative standard deviation (RSD) is0.2%-1.2%. The reproducibility for tests of1μg/L As(Ⅲ) and1μg/LCu2+has been improved by using adsorbent, in comparision with non-adsorbents richment.