Related Experiment Video
Updated: Jun 3, 2026

Aerobic Biodegradation Testing of Materials Using a Natural Marine Seawater Inoculum and Closed Loop Respirometer
Published on: October 24, 2025
Is the naphthalene sulfonate H-acid biodegradable in mixed microbial cultures under aerobic conditions?
T Olmez-Hanci1, I Arslan-Alaton, D Orhon
1Environmental Engineering Department, Istanbul Technical University, ITU, Insaat Fakultesi, 34469 Maslak, Istanbul, Turkey.
Abstract:
Synthetically prepared wastewater originating from the H-acid (4-Amino-5-hydroxy-2,7-naphthalene disulfonic acid) manufacturing process was subjected to respirometric analysis for evaluating the level of achievable biodegradation in the presence of this commercially important azo dye precursor. For this purpose, H-acid was mixed with synthetic substrate having the same characteristics as sewage at a concentration and composition being typical for H-acid manufacturing wastewater. Experimental results indicated that H-acid was not biodegradable under activated sludge treatment conditions even after prolonged acclimation periods. The results were also confirmed by model evaluation of oxygen uptake rate profiles. H-acid also did not inhibit the biodegradation of synthetic sewage but accumulated as soluble inert COD in the treated wastewater.
Related Concept Videos
Microbial Bioremediation of Hydrocarbons
Microbial Wastewater Treatment
Microbial Bioremediation of Pesticides
Production of Organic Acids
Bioplastics
Microbial Bioremediation of Plastics

