From High‑Salinity Wastewater to Refinery Effluent: Reliable AOX/EOX/TOX Measurement on One Unified Platform in Compliance with EPA 9020B, 9023, and 9076

New Organic Monitoring Techniques
Oral Presentation

Prepared by P. Bhatt
Analytik Jena, 14517 Kirby Dr, Houston, Texas, 77047, United States


Contact Information: [email protected]; 470952444

ABSTRACT

Halogenated organic compounds remain a critical class of environmental contaminants due to their persistence, toxicity, and potential for bioaccumulation. Regulatory bodies increasingly rely on AOX (Adsorbable Organic Halides), EOX (Extractable Organic Halides), and TOX (Total Organic Halides) measurements to assess the presence of halogenated species in wastewater, industrial effluents, and complex environmental matrices. Because these analytes can impact biological treatment performance, form carcinogenic disinfection by‑products, and indicate upstream industrial contamination, reliable halide monitoring is essential for both environmental protection and process optimization.

Despite their regulatory importance, AOX, EOX, and TOX analysis presents notable challenges. Traditional workflows often require multiple instruments or separate configurations to accommodate different sample types, oxidation techniques, and concentration ranges. The broad working range needed, from low‑µg/L concentrations in treated wastewater to mg/L levels in industrial feeds, further complicates method development and increases operational costs. Variability introduced by photosensitive electrode reactions and routine maintenance of electrochemical detection systems can also affect long‑term data stability.

This work evaluates the performance of the multi X 2500 or multi EA 5100 as a unified platform capable of analyzing AOX, EOX, and TOX within a single system configuration. Real‑world samples, including high‑salinity wastewaters and refinery effluents, were used to assess robustness, sensitivity, and linearity across a broad concentration range. Special emphasis is placed on the instrument’s Sens Cell design, in which a combined electrode configuration minimizes photosensitive side reactions, enhances baseline stability, and delivers long‑term reproducibility with significantly reduced maintenance requirements. Collectively, the results demonstrate how a single versatile platform can overcome common analytical barriers in AOX/EOX/TOX determination