Adsorption of petroleum products by modified and activated adsorbents

This research is aimed at investigating the adsorption of petroleum products from aqueous solutions by adsorbents modified with HCl and those activated by microwave radiation. The research objects were carbon adsorbents: activated coals, such as AD-05-2, IPI-T, KAD-iodine and zeolites of the TransBaikal deposit. The quantitative analysis of waters (standardised test solutions with an initial concentration of petroleum products not exceeding 10 mg/l) was carried out by the fluorimetric method using a Fluorat-02 liquid analyser. The adsorbents were activated in a microwave oven at a wave power of 800 W for 1 min. The modification was carried out according to the following procedure: 10 g of the adsorbents dried to a constant weight at a temperature of 120-150 °C were stirred for 24 h with 200 ml of a 12% HCl solution in water.Next, the suspension was filtered and washed with distilled water until neutral. It was found that the value of adsorption of petroleum products by adsorbents modified with HCl increases by 3.8 times for activated carbon KAD-iodine, 0.5 times for IPI-T, and equals 0.71 mg/g and 0.80 mg/g respectively. Among the studied sorbents, these sorbents have the largest grain size (3-5 mm) and micropore volume (0.28-0.29 cm3/g). It was established that the method of short-term (within 1 min) microwave activation makes it possible to increase the adsorption of petroleum products by: 4.2 times for activated carbon KAD-iodine and 0.6 times for IPI-T in comparison with the original adsorbents. The highest adsorption value of petroleum products corresponds to zeolites and equals 0.99 mg/g. The action of microwave radiation is associated with the dissociation and evaporation of the water bound in the adsorbents and flammable organic substances, which leads to an increase in the porosity of the adsorbent. The application of the microwave activation method is highly promising in comparison with the classic methods of chemical and steam-gas activation. This method simplifies the technological design and reduces the consumption of reagents for the production of effective adsorbents used to extract petroleum products from aqueous solutions, which acquires particular importance in the context of maintaining the environmental safety of water use.