Development of Novel Spectrophotometric Analytical Methods for Evaluating Environmental Water Quality and Its Applications

Water is an essential part of our everyday lives, and therefore proper management and monitoring of water quality is important to ensure safe water supply for aquatic life and drinking. In this study, novel spectrophotometric analytical methods were developed for evaluating environmental water quality and its applications. First, the proposed method is based on spectrophotometry and visual colorimetry using a membrane filter enrichment technique for the sensitive detection of arsenic in groundwater. It was successfully applied for groundwater sample containing 10 mu g L-1 arsenic without any expensive instrumentation. Second, a spectrophotometric fiber optic sensor enables the real-time monitoring of calcium carbonate and silica scale formation in geothermal water. The proposed sensor detects the refractive index changes surrounding the exposed core of the fiber optic by scale formation. Third, a simple method used to determine of anionic surfactants based on an evanescent wave fiber optic was developed using ethyl violet. Finally, the novelty of the proposed method is combining both electrochemical and spectroscopic selectivity techniques used to detect the presence of heavy metals in a water environment. This sensor consists of indium tin oxide coated on a fiber optic, which can detect the refractive index changes of electrochemical reactions in heavy metals.