Abstract
The article presents the impact of ecological additives on selected parameters and the microbiological distribution of marine engine oil (Marinol). With the development of industry and the automotive sector in general, it has become apparent that the problem of microbial contamination is still relevant and is becoming increasingly widespread. The author decided to investigate the impact of additives, namely silver and effective microorganisms with a 2% percentage share in marine engine oil (Marinol), on selected parameters and on slowing down the growth of bacteria and fungi. The article presents the impact of additives on selected engine oil parameters, including flash point, water content, acid and base numbers, density and kinematic viscosity. In addition, the oil was also tested for the effect of additives on the inhibition of microbial decomposition in the tested oil. It was found that the best additive with a positive effect on engine oil parameters and microbial decomposition was a silver solution and effective microorganisms in the form of ceramics. The addition of effective microorganisms in liquid form and silver solution to used oil resulted in an increase in temperature of approximately 1 °C compared to the ignition temperature of oil without additives. For the addition of colloidal nanosilver, a temperature of 225.22 °C was obtained. For used oil, the water content increased to 0.16% from 0.1% for new oil. The addition of liquid effective microorganisms caused the largest increase in water content to 0.58%, while EM in the form of ceramics did not contribute to the increase in water content due to its composition. The addition of silver solution contributed to an increase in water content to 0.47% and colloidal silver to 0.53%. The base number of used motor oil without additives decreased from 11.82 mgKOH/g for fresh oil to 11.52 mgKOH/g. After the application of ceramic effective microorganisms, a lower base number was obtained compared to oil without additives, which is 11.34 mgKOH/g, while liquid effective microorganisms reduced the base number the most, to 11.27 mgKOH/g. Each of the additives caused a decrease in bacteria and fungi compared to used oil without additives. The use of these additives is an original solution that has a positive effect on the microbial degradation process, while maintaining the original performance parameters of the engine oil. In the next stage, it would be desirable to confirm the results obtained under actual operating conditions.