以離子樹脂縮時包監測水中重金屬

Abstract

不肖廠商偷排廢水事件時常發生，環境遭受危害日甚。這類事件具有不定時、延時短、污染濃度高且地點分散等特性，而連續監測成本高昂，以致偷排違法行為難以掌控。本研究目的在發展「離子樹脂縮時包」為環境鑑識方法，鎖定廢水違法排放之區域與廠家，提供政府相關單位有效途徑，用以監督及保護灌溉水及土壤品質。本研究利用離子交換樹脂為基材做成低成本的離子樹脂包，大量投放於監測區域，在一段時間後收回樹脂包測定所吸附之重金屬，污染源的分布特性即可掌握，使污染行為人難以遁形。本論文研究之「離子樹脂縮時包」分為實驗室與現地試驗兩個部分進行。實驗室試驗結果顯示陽離子交換樹脂在與水體接觸30分鐘後，對重金屬的吸附效率即可達40%以上；在離子交換樹脂之交換容量未達飽和的情況下，重金屬濃度的高低對離子交換樹脂吸附效率並無顯著差異。現地試驗部分，將離子樹脂包投放在彰化縣東西二、三圳灌溉區8.8平方公里之圳道中151個監測點位，設置時間分7、14、21天。收回之樹脂包以Itrax螢光光譜儀檢測其重金屬峰度值，並以主成分分析檢測數據而歸納出4個主要變數，分別為天然背景因子，地區特性背景因子，金屬表面處理業及電鍍工業排放因子。此論文研究結果為進一步監測研究計畫及應用性提供了良好的基礎。

Unlawful manufacturers have often discharged their wastes secretly and caused severe damages to our environment. These kind of polluting events are usually done unpredictably in a short time without any sign, but the discharges could be highly concentrated and the locations are quite uncertain and dispersed. The goal of this study is to develop the ion exchange resin pack as an environmental fingerprinting method, which will enable the regulatory agencies to monitor and identify illegal polluters, in order to assure irrigation water and soil quality. In this study, inexpensive ion exchange resin packs are developed and deployed for a given period of time in the areas being monitored. After the packs are recovered, we can then determine the amount of heavy metal in ion exchange resin packs and identify the distribution of the hidden pollution sources. This study was divided into two parts, the laboratory experiments and the field testing respectively. The results of the laboratory experiments show that approximately 40% of the heavy metal ions were absorbed onto cation exchange resin from aqueous solution in 30 minutes. There were no significant differences in the percentage being absorbed at various concentrations tested as long as the resins did not reach exhaustion in the range we tested. In the field experiment, we chose Changhua as a study area. There were 151 point sites in two canals and each site was placed three packs for monitoring time for 7, 14, and 21 days. Metal ions in the recovered packs were determined with an Itrax X-Ray fluorescence mass spectroscopy. The principal component analysis (PCA) method was used to analyze the data which indicated that there were 4 principal components, the natural background (PC1), the background of the monitored area characteristics (PC2), the metal treatment and the electroplating industry (PC3 and PC4). It is expected that these results will provide a good foundation for further research and applications of this monitoring method.