幾丁聚醣固化於氫氧化鐵吸附水中二價銅之研究

Adsorption of Copper (Ⅱ) Ions from Aqueous Solution by Chitosan-coated Granular Ferric Hydroxide

近年來，由於科技發展迅速，工商業界進步飛快造就了進步的物質生活，也帶來環境的隱憂。環境品質是有目共睹的每況愈下。隨著工業快速的發展，重金屬汙染已形成了一種全球性危害。存在於上壤及地下水中之重金屬，經由直接或間接的管道，造成環境及人體的傷害。因此，如何有效的處理地下水之重金屬問題，已成為現今環境保護之重要課題。復育(Remediation)為地下水中之重金屬汙染防治技術之一，兼具回復大地原貌的特色，其中生物復育技術則是利用天然微生物其分解者的角色降解或打斷有害物，使其形成低毒性或無毒產物的處理方法。生物復育能減輕環境對污染的負擔及降低處理成本，也提供較安全較符合自然法則的淨化方法，是未來解決環境污染的重要發展方向。本研究使用生物可分解之材料幾丁聚醣，利用商業市售之氫氧化鐵(Granular Ferric Hydroxide, GEH)模擬彰化第三淨水場之淨水污泥作為吸附劑，並搭配幾丁聚醣為吸附劑，進行重金屬銅的吸附叫行性研究。其結果顯示，在單純使用GEH之情況下對於重金屬銅，具有其可吸附一定量之吸附效果(4.89 mg/g)，而隨著幾丁聚醣的添加與重量配比的增加下，可得知其吸附量也相對的上升。此外，其吸附過程較符合擬二階反應(Pseudo-second-order reaction)。在以復育環境為前題下，顯示出可將含氫氧化鐵之淨水污泥再利用可行性。

With the dramatic develop of industry, heavy metal pollution has become a global environmental considerations. The heavy metals in the soil and groundwater have endangered our environment and human body by direct or indirect pathway. Thus, how to solve efficiently the heavy metal pollution in groundwater has become the most essential issue around the world. Theoretically, the one of most efficiency treatment methods for groundwater contaminated site was ”ex-situ” and ”in-situ” remediation. The most widely application based on the idea of in-situ remediation in US is permeable reactive barrier, due to its economical efficiency in treating large contamination area, and was widely accepted as an efficiency technology for groundwater remediation. This research is based on the ideal of green design and using biodegradable material (Chitosan) coated with iron hydroxide (GEH), which performed the process optimization for this biodegradable adsorbent. The optimized adsorbents executed the adsorption studies, and evaluated the isothermal studies for heavy metals (Cu(Ⅱ)). Moreover, the kinetic data were tested using pseudo first-order and pseudo-second order reaction. The kinetics experimental data followed pseudo-second order reaction which indicated that the chemical sorption is the rate-limiting step. Therefore, in the aspect of the environmental remediation, the adsorption results of GEH indicated that the recycle and reuse of waste sludge from water treatment plant could be a possible method in the future.