Overview
EN ISO 10707:1997 is an internationally recognized standard published by CEN (European Committee for Standardization) that outlines a reliable method to evaluate the "ultimate" aerobic biodegradability of organic compounds in water. This approach uses the closed bottle test, measuring biochemical oxygen demand (BOD) to assess the breakdown of organic substances by aerobic microorganisms. The standard applies to organic compounds with sufficient water solubility for stock solution preparation or, with special dosing, to those that are poorly soluble in water.
Understanding and following this standard is essential for laboratories, environmental monitoring organizations, regulatory agencies, and industries concerned with evaluating the environmental impact and biodegradability of chemical substances in aquatic environments.
Key Topics
- Aerobic biodegradability assessment: Evaluates the ability of microorganisms to fully degrade organic compounds into carbon dioxide, water, mineral salts, and new biomass under aerobic conditions.
- Closed bottle BOD measurement: Uses completely filled, sealed bottles to minimize contamination and oxygen ingress for accurate, repeatable BOD measurement over a 28-day test period.
- Applicability: Suitable for a wide variety of organic compounds, including those with low water solubility when appropriate dosing techniques are used.
- Biodegradation calculation: BOD values are corrected for blank samples and can be compared to theoretical oxygen demand (ThOD) or chemical oxygen demand (COD) for biodegradability expression.
- Test conditions and controls: Enforces strict sample handling, incubation at controlled temperature (20–25°C), and the use of blanks and reference compounds for valid results.
- Precautions and safety: Emphasizes safe handling of sewage, activated sludge, and potentially toxic test substances, reflecting best practices in water quality testing.
Applications
- Environmental monitoring: Essential for determining the impact of chemicals, pharmaceuticals, or wastewater on aquatic ecosystems.
- Regulatory compliance: Supports manufacturers’ and laboratories’ needs to meet legal and environmental requirements related to water quality and chemical discharge.
- Research and development: Facilitates product development by allowing assessment of biodegradability of new compounds or formulations prior to market release.
- Wastewater treatment evaluation: Assists in monitoring and optimizing treatment processes for industrial and municipal effluents.
- Ecolabeling and certification: Provides scientifically robust data for sustainability claims or eco-certification processes related to chemical products.
Related Standards
Organizations relying on EN ISO 10707:1997 may also refer to the following complementary standards for comprehensive water quality analysis and biodegradability testing:
- ISO 5814: Water quality - Determination of dissolved oxygen by electrochemical probe
- ISO 5813: Water quality - Determination of dissolved oxygen using the iodometric method (Winkler method)
- ISO 6060: Water quality - Determination of chemical oxygen demand (COD)
- ISO 9887: Water quality - Evaluation of the aerobic biodegradability of organic compounds in an aqueous medium (semi-continuous activated sludge method)
- ISO 9888: Water quality - Evaluation of aerobic biodegradability of organic compounds in aqueous medium (static test, Zahn-Wellens method)
- ISO 10304-2: Water quality - Determination of dissolved anions by ion chromatography, including nitrates and nitrites relevant for BOD test corrections
By following EN ISO 10707:1997, organizations ensure accurate, comparable, and reproducible results for assessing the aerobic biodegradability of organic compounds-crucial for protecting water quality, public health, and environmental sustainability.