The situation of the Polish oil industry after independence was difficult. Cut off from pre-war markets, the weakness of the internal market and increasing competition in external markets resulted in low profitability and a successive decline in production volumes. Competition also became a new threat from the state-backed distillery industry, which was pushing the concept of marketing fuel blends containing spirits. Their entry into the market, despite the objections of oil companies, meant that some gasoline had to be replaced with spirits and their ability to sell on the domestic market was limited. The negative effects of this were consistently raised by oil industry representatives. It wasn't until an improvement in the economy in the second half of the 1930s that a gradual change in the perception of spirit propelled blends appeared. Under conditions of growing domestic demand with relatively constant production volumes, a significant reduction in fuel exports became possible, and spirits were able to become a desirable additive to diesel blends, as evidenced by the increase in their purchases by oil companies.
The aims of the current study are the physicochemical characterization, spatial assessment and monitoring of hydrocarbon contamination in quagmire of three sites (Agreb, Gassi and Zotti) in the Hassi Messaoud region (Algerian Sahara), as a result of the presence of an important oil industry rejecting industrial wastewater. Samples were obtained from three different depths for each site. Total Hydrocarbons (THC) were determined by a gravimetric method, and the four (F1:C6-C10), (F2:C10-C16), (F3:C16-C34) and F4>C34) hydrocarbon fractions and BTEX (Benzene, Toluene, Ethyl-benzene and Xylene) were determined by using gas chromatography (FID). The results obtained show a high contamination with hydrocarbons in different sites and depths. The concentrations of THC, four hydrocarbon fraction and BTEX recorded on Agreb site in different depth were in this order: 51200–120000 mg/kg d.w.;