Evaluation of the efficiency of sorbents for accidental oil spill response in the Arctic waters

The development and operation of new oil fields on the Arctic shelf increases the risks of oil spills, which require the use of oil spill response tools and materials that are efficient in harsh climatic conditions. The question of actual efficiency of sorbents for reducing the level of oil pollution in the conditions of the Arctic and subarctic waters is relevant. The work is aimed at a comparative study of the efficiency of sorbents of mineral and organic origin used by coastal enterprises in the Kola Bay as well as a sorbent based on chitin in model systems simulating real conditions in sea waters. The characteristics of sorption agents were determined applying ASTM F716-18 procedure. Sorption capacity was evaluated in respect of ARCO grade oil, diesel fuel and marine oil. The efficiency of sorbents was estimated in model systems “sea water – oil” at water temperature corresponding to the average annual surface temperature in the Barents Sea. Actual data on sorption capacity of commercial sorbents “Lessorb”, “Novosorb”, a sorbent based on vermiculite and chitin sorbent in relation to potential pollutants of waters were obtained. The dynamics of sea water saturation with oil products at –0.5 (±1) and 10 (±1) °С was determined. It is shown that at higher temperature the concentration of oil products in sea water column (in the presence of an oil film on the surface) is on average four times higher than at low temperature. Kinetic dependences were obtained that describe the content of oil products in water column and near-surface layer of sea water in the presence of the studied sorbents at 5 (±1) °C, corresponding to the average annual temperature in the Kola Bay of the Barents Sea. A method is proposed for evaluating the efficiency of sorbents from the values of regression coefficients characterizing the dependence of oil products content in sea water on the character of sorbent and duration of its action.