Establishment of Methods to Identify Pollution Sources in a River Reach through Receptor Models

Given scientific and technological advances, the proportion of industrialization has increased, making industrial wastewater pollution more harmful to the environment and human health. Identifying sources of pollution in specific areas helps clarify and facilitate water quality management. This study established a method to identify sources of pollution in a river reach. River water sample collection was conducted twice a day for 30 days in a polluted river in southern Taiwan at sampling sites upstream and downstream of the river reach. Wastewater samples from potential sources of pollution were also taken during the monitoring period. The pollutant concentration data for the river reach was calculated based on the mass flow rate at two sites divided by the volume flow rate. Positive matrix factorization was applied to the 31 elements measured in the river to resolve source profiles and contributions. The results revealed that the contributors to pollution were sewage treatment (37%), metal finishing (8%), and a detention pond (39%). Furthermore, by comparing the results of the single- and multiple-site analyses, the difficulty of identifying sources of pollution due to the mixed-source profiles obtained was reduced. Consequently, the applicability and effectiveness of the proposed pretreatment method of pollutant concentration calculations from two sites were demonstrated. The novelty of the study lies in the establishment of a pollution source identification method that can assist in identifying the main polluting industry categories in river reaches.