Review of the state-of-the-art for monitoring urban drainage water quality using rhodamine WT dye as a tracer

ABSTRACT With increasing urbanization, wastewater and industrial effluents are being discharged into watercourses. Due to high-density development, it is difficult to construct conventional flow measurement structures like weirs. Hence, to measure the flow, dye tracing studies are an appropriate method for urban drainage channels. Dye tracing studies along with water quality monitoring can be analyzed to understand the behavior of pollutants in specific sections of the study area. This paper presents a state-of-the-art review for employing dye tracing studies to ascertain the pathways of pollutants and a case study. A dye tracing study was carried out at the Kolshet drain, Thane, India, to conceptualize contaminant transport using rhodamine WT (water tracer) dye. The study was carried out jointly by the Indian Institute of Technology Bombay, India and the University of Warwick, UK. Rhodamine WT dye was injected at the injection point and the distribution of dye concentration with time was logged with four portable fluorometers installed at measurement points. The data were analyzed and the longitudinal dispersion coefficient (‘DL’) for solute transport in the drain was computed.