The biotechnology of railroad crashed stone ballast remediation with simultaneous producing of fatty acids suitable as biodiesel precursors

The authors have developed the biotechnology of railroad crashed stone ballast remediation with simultaneous producing of fatty acids suitable as biodiesel precursors using the algal-bacterial-yeast consortium and the biogeosorbent on its basis. The efficiency of petroleum hydrocarbons removal during exposition to biological aditives under vigorous stirring was 97-98 %. Even on the repeated use of the same suspension, the optimal number of cycles to tumble ballast efficiently was determined to be 5. A decline of the petroleum hydrocarbon content to acceptable norms for the allowable residual content of oil in the soil was achieved in 90 days after plowed-down application of tank bottoms. Fatty acids of the suspension of the algal-bacterial-yeast consortium have a low value of the unsaturation degree suggesting the high biofuel oxidation stability. The cetane number, iodine value, and physicochemical properties of renewable fuels produced comply with the requirements of the European Standard EN 14 214 and the Russian National Standard 33131-2014, regardless of the exposure time.