Acute toxicity of rich triethylene glycol on juvenile African freshwater catfish (Clarias gariepinus) around a natural gas dehydration facility

Abstract

Abstract Triethylene glycol (TEG) removes equilibrium water from natural gas but may spill during equipment maintenance and other poor safety practices. Studies on the toxicity of rich TEG in aquatic habitats are scarce. In this study, the toxicity of rich TEG on freshwater juvenile African catfish (Clarias gariepinus) test organism was conducted. The experimental design for the toxicity tests was 3 × 5 × 6 factor in a randomized complete block design, with six levels of treatment, observed at five intervals and in three replicates. The acute toxicity was carried out by exposing them to various lethal concentrations of the Rich TEG in solution. Physicochemical parameters, including temperature, dissolved oxygen, pH, conductivity, and total dissolved solids, were measured and recorded for five test concentrations of 25.92, 12.96, 6.48, 3.24, 1.62, and 0.0 ml/l (control). The concentration responses for the fish mortality at 24, 48, 72, and 96 h were also derived. No mortality was observed between Rich TEG concentrations of 0 ml/l to 25.92 ml/l after 72 h of exposure. However, some mortality was observed between 1.62 ml/l to 25.92 ml/l after 96 h of exposure. The highest concentration of 25.92 ml/l recorded a higher mortality of 6.0 ± 0.4, which is an average of 60%, while the lowest mortality was recorded in the control (0 ml/l), at an average of 0% mortality rate. The results underscore the concentration-dependent effects of rich TEG on the test organism, highlighting the need for targeted attention to higher concentration levels.

Keywords

• Natural gas dehydration
• Triethylene glycol
• Toxicity
• Environmental sustainability