Estimation of efficiency removal of oil products dissolved in water by processed waste of polymer packaging in the medium of vegetable surfactants
Authors:   Ivano-Frankivsk National Medical University, Malyshevska O. S. 
Published: May 2021

Introduction. We have tried to solve two environmentally dangerous problems at the same time - water pollution by petroleum products and the growth of polymer packaging in the share of household waste. On the one hand, oil pollution is one of the largest and most dangerous types of human impact on the environment. In oil-contaminated reservoirs, depending on the concentration of hydrocarbons in the water, adult fish, caviar, larvae and young fish die on the surface of the water and in shallow water. Zooplankton in a polluted reservoir dies completely. It is established that only 1 g of oil kills all living things in 1 m3 of water. It is known that polymer waste can absorb a small amount of petroleum products (from 1.4 to 1.6 g / g) depending on the type of polymer. To increase the oil content of the polymer, in addition to increasing its specific surface area (eg, fiber cutting), surfactants (surfactants) are applied to the surface, which improve the adhesion of the polymer to the petroleum product and, thus, increase the sorption of the polymer. Mechanical treatment of the polymer surface does not have a negative environmental impact on the environment, unlike surfactants, which actively pass from the polymer surface into moist soil and water and cause pollution. However, the refusal to apply surfactants on the polymer surface makes polymer sorbents inefficient, economically and environmentally impractical due to the need to use them in large quantities. In addition, after their use, a new problem arises - highly toxic waste that needs to be disposed of. In our opinion, one of the options for solving this problem is the use of surfactants from vegetable raw materials. The purpose and objectives of the study. The research aimed to hygienically substantiate the possibility of using sorbents, which are made from household polymer waste with the simultaneous application of environmentally friendly vegetable surfactants on their surface, to extract petroleum products from water. To achieve this goal, the following tasks were solved: 1. Investigate the possibility of using environmentally friendly surfactants from plant materials common in Ukraine to increase the extraction of oil from water. 2. To establish the possibility of using secondary polymer raw materials from packaging waste as oil sorbents. 3. Investigate the possibility of increasing oil recovery by sorbents from secondary polymer raw materials from packaging waste by means of their mechanical activation and application of vegetable surfactants to the surface of the sorbent. 4. Design an installation for the separation of oil from oil-water mixture. Methods and methodical: The study was conducted using: petroleum sludge, vegetable surfactants based on soapwort (Saponaria officinalis L), horse chestnut (Aesculus hippocastanum), waste PET (polyethylene terephthalate) packaging. Research methods: photometric, which was implemented using a photocolorimeter CPK - 2. The method of intensification of oil extraction from water was based on the method of flotation purification of water from oil using surfactants, according to which surfactants are introduced into the water-oil mixture and saturate the mixture with air, while foaming the mixture and oil, "sticking" to bubbles The surfactant is washed out of the water and moved to the water surface together with the foam. After that, the resulting foam is removed from the surface by various devices and methods. Results.To determine the amount of oil in the solution used the method of calibration graph, based on the reduction of light flux when passing through the oil solution; The study was performed on the photocolorimeter. To do this, we prepared a series of water-oil solutions with a known concentration of oil in them and found the heights of polarographic waves. After constructing a calibration graph on the value of the height of the polarographic wave, established experimentally, found the concentration of oil in the mixture. The result was much lower than expected: the oil concentration after purification with surfactant 1 was 2.27 ml / dm3, for surfactant 2 - 2.88 mg / dm3. For example, compared to the most environmentally friendly surfactant sodium laureth sulfate, the degree of oil recovery was 2.6 times lower, ie only vegetable surfactants themselves did not clean the water-oil mixture from oil. In the next stage of our experiment, to improve the extraction of oil from the water-oil mixture, we used as a collector plates made from recycled packaging waste with smooth and rough surfaces. The dimensions of the plates were 1 cm × 10 cm. The result of the use of mechanically recycled polymer packaging waste during flotation is a decrease in the concentration of oil in the water-oil mixture in the surfactant medium with: PET 2.2 times, PVC - 2.5 times, PP - 2.4 times, PE - 2 , 1 times; in the environment of surfactants 2 of: PET 1.6 times, PVC - 1.9 times, PP - 1.8 times, PE - 1.6 times. Additional mechanical activation of polymer packaging waste increases the extraction of oil, during flotation, from the water-oil mixture in which vegetable surfactants are present: for PET 3.4 times with surfactant 1 and 1.9 times with surfactant 2; for PVC 4.3 times with surfactant 1 and 2.22 times with surfactant 2; for PP 3.8 times with surfactant 1 and 1.6 times with surfactant 2; for PE 3.3 times with surfactant1 and 1.8 times with surfactant 2. Application to the surface of mechanically activated polymer waste solution of surfactant 1 significantly increases the amount of extracted oil from water-oil mixtures during flotation in surfactant medium 1: for PET 8.8 times (88.6%) to 0.243 mg / dm3 1.15 times lower than the maximum allowable concentration of oil in drinking and domestic water; for PVC waste 9.9 times (90.1%) to 0.218 mg / dm3, which is 1.3 times lower than the MPC of oil in drinking water and domestic water; for PP waste 9.5 times (89.6%) to 0.229 mg / dm3, which is 1.25 times lower than the MPC of oil in drinking water and domestic water; for PE waste 8.4 times (88.15%) to 0.258 mg / dm3, which is 1.1 times lower than the MPC of oil in drinking and domestic water. Conclusions. 1. A simple laboratory installation for flotation separation of oil from oil-water mixture using surfactants is designed. The efficiency of purification of water-oil mixtures by the plant using vegetable surfactants with the simultaneous use of sorbents from polymer mechanically activated waste, the surface of which is covered with vegetable surfactants, increases the degree of purification of water-oil mixtures by the plant up to 90.1% 2. It is established that the use of foaming agent from Saponaria officinalis L during flotation separation of water-oil mixtures allows to extract up to 32.4% of oil from mixtures. The surfactant from Saponaria officinalis L is an environmentally safe and quite effective dispersant, so it can be recommended for intensification of purification of water contaminated with dissolved oil.