According to the European Environmental Agency 2018 Report, approximately 40% of surface water, including rivers, lakes, and coastal areas, is deemed to have good ecological status or potential, while 38% maintain good chemical status. The widespread use of chemicals in daily routines and unrestricted access to medications have led to increased waste generation and the release of conventional and emerging organic compounds into the surrounding environment.
Determining the level of organic pollution in wastewateris essential for managing water effectively and safeguarding our environment. In this blog, we will explore the importance of monitoring organic pollution in wastewater and discuss common methods used to determine its presence and concentration.
What is Organic Pollution in Wastewater?
Organic pollution in wastewater refers to the presence of organic substances that result from human and animal activities, industrial processes, and the natural decay of organic matter. These organic compounds include dyes, phenolic compounds, pesticides, humic substances, pharmaceuticals, and industrial effluents. When discharged into water bodies without proper treatment, these pollutants can cause oxygen depletion, leading to the formation of “dead zones” and disrupting aquatic life.
Wastewater treatment facilities heavily depend on biological processes to degrade the diverse array of organic compounds present in wastewater and continuously seek innovative ways to enhance their operations. Through these biological processes, wastewater is transformed into effluent, which is subsequently reintroduced into the water cycle after it has been treated. Common methods used to analyze organic contaminants in wastewater are described below.
Biochemical Oxygen Demand (BOD)
BOD is one of the most widely used methods for assessing organic pollution in wastewater. It measures the amount of oxygen consumed by microorganisms as they decompose organic matter in a sample over a specific period, usually five days (BOD5). The BOD test indicates the degree of pollution and the potential impact on aquatic life. A higher BOD level suggests a greater organic load and a higher demand for oxygen, indicating more severe pollution. High BOD levels in sewage can lead to a significant reduction in oxygen levels in water bodies that receive sewage, ultimately resulting in the death of certain organisms due to oxygen depletion.
Chemical Oxygen Demand (COD)
COD is another essential parameter used to quantify the amount of organic pollution in wastewater. Unlike BOD, COD measures the oxygen equivalent required to oxidize both biodegradable and non-biodegradable organic substances chemically using strong oxidants such as potassium dichromate. The COD test provides a rapid and robust assessment of organic content in wastewater, making it particularly useful for industrial wastewater monitoring and process control.
Total Organic Carbon (TOC)
TOC analysis measures the concentration of carbon in all organic compounds present in wastewater. This method involves the oxidation of organic carbon to carbon dioxide (CO2) and its subsequent detection. TOC analysis is fast and can provide real-time data, making it suitable for continuous monitoring of organic pollution in wastewater treatment plants.
Though not commonly used, UV-visible spectroscopyis a robust technique used to determine the concentration of specific organic pollutants in wastewater. Organic compounds absorb light at specific wavelengths, and by measuring the absorbance, the concentration of the pollutants can be determined. UV-visible spectroscopy is valuable for identifying and quantifying individual pollutants, especially when their characteristic absorption spectra are known.
Wastewater LIMS – An All-in-One Lab Assistant for Organic Pollution Testing
A Laboratory Information Management System (LIMS) plays a crucial role in supporting wastewater testing by streamlining sample tracking, data management, and analysis. A wastewater LIMS efficiently manages the entire testing process, from sample collection to result reporting, ensuring accurate and reliable data. Additionally, a LIMS enables seamless integration with various analytical instruments and software, automating workflows, eliminating data silos, and reducing human errors. Furthermore, a wastewater LIMS helps meet compliance with standards such as ISO 17025, US EPA, NELAC, and local regulatory guidelines. This enhances the overall efficiency and operational quality of wastewater testing laboratories.
Monitoring organic pollution in wastewater is a vital step in preserving water quality, protecting aquatic ecosystems, and ensuring public health. By employing various analytical methods like BOD, COD, TOC, and UV-visible spectroscopy, lab managers can accurately assess the level of organic pollution and empower regulatory authorities to make informed decisions on wastewater treatment and discharge practices. A wastewater LIMS supports the integration of various testing methods, allowing for a comprehensive analysis of organic pollutants present in wastewater. Furthermore, it significantly enhances the reliability and effectiveness of testing through quality control processes, contributing to the preservation of water quality and ecological balance.