ISO 6853:2001

Overview

ISO 6853:2001 specifies an analytical procedure for the determination of ammoniacal nitrogen in photographic processing wastes using a microdiffusion method. The method measures ammonia (and other volatile amines expressed as nitrogen) liberated from photoprocessing effluents by strong alkali, with results reported as nitrogen. It is intended for typical photographic effluents in the range 10–200 mg/L ammonia (8–160 mg/L as N). ISO 6853:2001 is essential for laboratories and photographic facilities that must quantify ammonia in waste streams for environmental monitoring or regulatory compliance.

Key Topics

• Principle: Ammonia is released from the sample by treatment with potassium metaborate/tetraborate and absorbed into a boric acid solution in a microdiffusion cell; the absorbed ammonia is then determined by titration with standardized sulfuric acid.
• Microdiffusion cell: Small covered device with concentric chambers (sample, sealant, absorbent) to ensure efficient room-temperature diffusion from sample to absorber.
• Analytical range: Designed for ammonia concentrations of 10–200 mg/L (8–160 mg/L N); other volatile amines are determined as ammonia but are usually present at low levels in photographic wastes.
• Reagents & solutions: Includes potassium tetraborate solution, boric acid absorbent, standardized sulfuric acid titrant, and sodium hydroxide buffers; reagent purity and preparation details are specified.
• Procedure controls: Use of standard nitrogen solutions to check recovery and technique; caution against scaling up sample-to-buffer ratios because diffusion rates will change.
• Safety & quality: Emphasizes PPE, handling of caustic/toxic chemicals, mandatory use of pipette bulbs or plunger pipettes, and proper reagent labeling and disposal.

Applications

• Environmental monitoring of photography processing waste and photographic effluents for regulatory discharge compliance.
• Quality control in photographic laboratories and chemical suppliers that handle photoprocessing effluents.
• Routine analytical testing by environmental, municipal or industrial laboratories assessing ammonia load from photographic operations.
• Baseline and compliance testing where accurate ammonia determination is required to design or verify wastewater treatment processes.

Related Standards

Standards referenced by ISO 6853:2001 include:

• ISO 648 (pipettes)
• ISO 5667-1/2/3 (water sampling guidance)
• ISO 6353-1/2/3 (reagent specifications)
• ISO 10349-1 (photographic-grade chemical test methods)

Keywords: ISO 6853:2001, ammoniacal nitrogen, microdiffusion method, photography processing waste, ammonia determination, photoprocessing wastes, photographic effluents.