Novel knowledge for identifying point pollution sources in watershed environmental management

Area of Science:

• Environmental Science
• Water Quality Management
• Industrial Ecology

Background:

• Identifying point pollution sources (PPSs) is crucial for regulating water quality (WQ) and penalizing illegal discharges.
• Existing methods lack a clear understanding of the link between water body pollutants and PPS emissions.
• This gap hinders effective PPS identification during water pollution incidents.

Purpose of the Study:

• To develop a novel framework for identifying PPSs using conventional chemical pollutants and a matrix calculations model (CCI-MCM).
• To establish a robust method for linking pollutant profiles to specific industrial sources.
• To enhance the accuracy and efficiency of PPS identification in water pollution events.

Main Methods:

• A two-step statistical and correlation analysis was performed on wastewater data from 256,025 PPSs.
• Developed similarity (SM-ISWI) and correlation (CM-ISWI) matrices for industrial wastewater indicators, distinguishing 41 industries.
• Constructed water quality concentration (WQ-CM) and correlation (WQ-CCM) matrices using index and Pearson correlation analyses.
• Applied a matrix calculation model with Z scores (Z_f, Z_c, Z_f-c) to assess PPS responsibility.

Main Results:

• The SM-ISWI and CM-ISWI successfully categorized pollution units and identified PPSs within 41 industries.
• WQ-CM and WQ-CCM highlighted pollutant anomalies in natural water bodies, providing data for PPS identification.
• The CCI-MCM demonstrated effectiveness in case studies, with True Positive rates (TE values) from 25.0% to 53.9%, significantly outperforming random sampling.
• The model successfully linked pollutants in water bodies to specific PPSs.

Conclusions:

• The novel CCI-MCM framework effectively identifies point pollution sources by analyzing pollutant associations.
• This method provides critical insights into the relationship between industrial discharges and water body contamination.
• The CCI-MCM offers a practical and enhanced approach for identifying PPSs in water pollution incidents, improving regulatory enforcement and environmental management.