Effect of an iron based modifier for liquid fuels combustion on the aquatic environment

The combustion of liquid fuels – first of all, heavy crude oils – leads to the formation of pollutants such as: nitrogen oxides (NOx), sulfur dioxide and hydrocarbons. The amount of such pollutants can be reduced by means of special modifiers, or additives. One such additive is a metallic modifier based on fatty acid ferric salts dissolved in fuel oil. Iron at high concentrations is known to be harmful to the aquatic environment, therefore the effect of the iron-based modifier on the aquatic ecosystem is presented in this paper. Specifically, the effect of its addition on algal growth inhibition, acute toxicity to rainbow trout, and reproduction of daphnia has been examined. According to the results, the concentration capable of reducing the rate of algal growth by 50% after 72 h is higher than 100 mg/L, the mean concentration capable of killing 100% of the trout population after 96 h (lethal concentration for 100%, LC 100 ) is higher than 320 mg/L, and, depending on the concentration, the rate of reproduction of Daphnia magna drops by 0.6%–16.7%, respectively. This means that, although capable of affecting the aquatic environment, the iron-based modifier does so only when it is applied at its maximum concentrations. Since it is used only in small quantities as a fuel additive, it will not threaten the environment.