[Photodegradation of UV filter PABA in nitrate solution]

Area of Science:

• Environmental Chemistry
• Photochemistry

Context:

• UV filters like p-aminobenzoic acid (PABA) are prevalent in aquatic environments.
• Nitrate ions are common water contaminants.
• Understanding PABA photodegradation is crucial for assessing environmental risks.

Purpose:

• To investigate the aqueous photolysis of PABA under simulated solar irradiation.
• To determine the influence of nitrate ions, pH, and humic substances on PABA photodegradation.
• To elucidate the role of hydroxyl radicals and identify photoproducts.

Summary:

• PABA photodegradation in nitrate solutions follows first-order kinetics.
• Increased nitrate concentration and pH accelerate PABA degradation.
• Humic substances inhibit photodegradation, while hydroxyl radicals play a significant role.

Impact:

• Provides insights into the environmental fate of PABA.
• Highlights the role of water chemistry in UV filter degradation.
• Informs risk assessment and water treatment strategies for PABA and similar compounds.