Monitoring Heavy Metal Ions in Water by Using Ion Exchange Resin Packs

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.