Możliwości usunięcia substancji ropopochodnych z sieci i instalacji wodociągowych

A rural water supply system was contaminated with crude oil along a length of several kilometres. The tap water had a disagreeable odour and carried oil spills on its surf ace. Prewashing with water was found to be insufficient. Analysis of pipe samples showed that crude oil had occluded on the iron-containing incrustation. On the basis of laboratory tests, a procedure was established for the removal of the oil-contaminated incrustation layer. The procedure involved a solution which was made up of NaHSO4, TPF and Roksol MS (a mixed nonionic and anionic surfactant). The pipeline was washed stepwise. The said solution was passed to particular pipe sections, and mixing was provided via air supply. After 24 hours of treatment, the pipe section was rinsed, and the effluent was collected in tanks before it was sent to the wastewater treatment plant. The rinsing procedure was discontinued after the concentration of anionic and nonionic surfactans decreased to the value of 0.1 g/m[3] and 0.2 g/m[3], respectively, and the tap water was free of benzene and of the typical crude oil odour.