Use of sorption minerals to remove petroleum substances from water

Purification of water from petroleum compounds is a very complex process depending on many factors. De-oiling of water is a very complex process, which is affected by a number of factors: variety of oils, nature of the oil-water emulsion (mechanical or chemical), degree of dispersion, presence of other compounds such as surfactants or other emulsifiers and stabilizers in water. For this reason, there are no universal de-oiling systems that can be used in any case. One of the methods that deserves special attention is the use of porous materials, that is, sorbents, which are readily available, simple to use, cheap and, which is important, non-toxic to the environment. The most accessible materials are natural. The aim of the work was to demonstrate the effectiveness of sorption minerals during the process of removing petroleum from water and to assess the absorbance capacity of the minerals studied. The removal process in presented studies was carried out using two natural sorbents: pumice and clinoptylolite. The pumice used was obtained from crushed and sifted natural pumice, while clinoptylolite came from tuffs mined in Slovakia. The study was conducted on simulated water (distilled water with a mixture of diesel and gasoline). The research was carried out to determine the efficiency of removal of petroleum substances by static and dynamic methods applying sorbents: pumice, clinoptylolite, and a mixture of clinoptylolite with pumice. Absorptivity of a given sorbent was tested and the value of mineral oil index was determined using gas chromatography. The absorption capacity of minerals was investigated by weighing a given sorbent before and after the test. The most absorptive material turned out to be the pumice that absorbed most of the solution: 199.8% - which was almost twice as much sorbate than the weight of the sorbent. The weakest absorption characteristics were revealed by clinoptylolite with the highest value being 70.3%, whereas for the mixture of clinoptylolite with pumice, the value was moderate -152.5%.