Use of an Effective Variance Chemical Mass Balance Model for Source Apportionment of Metal Elements in a Polluted River

This study aimed to determine the sources of water pollution in a major river in northern Taiwan using the characteristics of actual industrial wastewater and the effective variance chemical mass balance (EV-CMB) model. River water samples from 9 sampling sites and 14 profiles of potential sources were collected once on May 15, 2019, and 52 metal elements were analyzed. The metal index (MI) was used to monitor the levels of 11 hazardous pollutants in the water samples. The model results indicated that tungsten discharged by semi-conductor manufacturing (SCM) and copper discharged by bare printed circuit boards (BPCB) were the major sources of river pollution in the upstream and downstream areas, with contributions of 78% and 19%, respectively. In addition to SCM and BPCB, a high pollutant load was apportioned to domestic wastewater in the metropolitan area, corresponding to the distribution of the population. This study demonstrates the feasibility of applying the receptor model for the strategic investigation of river pollution and highlights the need for a comprehensive source profile database.