Phenols and Ammonia Determination in Water

Phenols are a group of organic compounds that are widely used in industrial processes, such as the production of plastics, dyes, and pharmaceuticals. However, their presence in water, even at low concentrations, poses significant risks. Phenols are highly toxic, have low taste and odor thresholds, and can persist in water for extended periods. Chlorophenols, a subgroup of phenols, are especially hazardous due to their carcinogenic properties.

The determination of phenols in water is critical for:

• Monitoring drinking water quality to ensure safety for human consumption.
• Assessing industrial wastewater to prevent environmental contamination.
• Complying with regulatory standards such as ISO 6439:1990, EPA Method 9065, and APAT CNR IRSA n° 5070A1.

The method described ➡️ IN THIS APPLICATION NOTE ⬅️ involves steam distillation followed by a colorimetric reaction with 4-aminoantipyrine, providing precise and reliable results even at low concentrations (0.005–0.100 mg/L). This procedure is optimized for use with the VELP UDK 149 Distillation Unit, ensuring high accuracy and reproducibility.

Ammonia is a common pollutant in water, originating from agricultural runoff, industrial discharges, and domestic wastewater. Elevated levels of ammonia can lead to eutrophication, oxygen depletion, and toxicity to aquatic life. In drinking water, ammonia can react with disinfectants like chlorine to form harmful disinfection byproducts.

The determination of ammonia in water is essential for:

• Evaluating water quality in drinking, surface, and groundwater sources.
• Monitoring wastewater treatment processes to ensure effective removal of nitrogen compounds.
• Complying with international standards such as ISO 5664, EPA Method 1690, and APAT IRSA 4030 C.

The Kjeldahl method, combined with spectrophotometric analysis, is a globally recognized technique for ammonia determination.
➡️ THIS APPLICATION NOTE ⬅️ describes how to achieve high precision and reproducibility with VELP's distillation units during routine analysis in environmental laboratories.