| 摘要: | 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。存在於土壤及地下水中之
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。
生物高分子聚合物(Biopolymer)，其具備有微生物可分解的特色
(Biodegrable Materials)，已成為釵h產業未來研發的趨勢。其中幾丁聚醣是
一種由生物體製取的天然陽離子型高分子聚合物，為幾丁質之衍生物，由
於結構中帶有大量的胺基、羥基之官能基，易於與金屬離子形成螯合或離
子吸附作用，對於廢水中之重金屬具有強的吸附能力。生物可分解材料於
使用後，進入回歸於大自然中循環，所以原料來源可不斷重複取得，符合
「永續利用」的原則。且因其化學結構、反應特性及可塑性等特性，目前
已廣泛的被應用於重金屬之吸附實驗中。
II
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
(GEH)並搭配幾丁聚醣為吸附劑，進行重金屬銅的吸附可行性研究。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，而在pH 值為2 時其吸附量皆為最小。此外，其吸附
過程較符合擬二階反應(Pseudo-second-order reaction)，並皆適用於Langmuir
與Freundich 吸附模式。研究之中也使用彰化第三淨水場之淨水污泥作為吸
附劑，而其結果顯示，污泥對於銅離子有其吸附之效果，其吸附量(7.03mg/g)
更高於使用商業化之氫氧化鐵，而在添加幾丁聚醣後，也相對提升其吸附
量；故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。
Because of 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.
Biopolymer is a biodegradable material, and becomes a newly
developing tendency for many industries. The formation of biodegradable
material is using nature organisms as the base unit, including microorganisms,
plants and animals. Moreover, the used biodegradable material can be degraded
by landfill, which provides the nutrient for microorganisms, plants and animals.
Thus, nature resources can be recycled and reused, which achieves the goal of
sustainable regeneration. Based on this concept, obtaining form insects, the shell
of aquatic coruscations (crab and shrimp), and the cell wall of fungus, Chitin
and Chitosan have widely applied in the adsorption study of heavy metal based
on their chemical structures, reaction characteristics and modification properties.
This research is based on the ideal of green design and using
biodegradable material (Chitosan) coated with iron oxide (GEH), which
performed the process optimization for this biodegradable adsorbent. The
optimized adsorbents executed the adsorption studies, and evaluated theisothermal studies for heavy metals (Cu(II)). The results indicated that the
copper adsorption capacity reached 4.89mg/g. The equilibrium adsorption data
were analyzed using Langmuir and Freundlich isotherm model, where the
results fitted well in both two isotherm models. The maximum adsorption
capacity calculated from Langmuir adsorption isotherm was 7.03 mg/g GEH for
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. |
