| Abstract [eng] |
Microplastic pollution is one of the main problems in our environment nowadays. This problem grows together with high demand of plastic products in our society. Micro-plastics are found everywhere – in animals’ stomach, in our food, in oceans and in soils. Some sources claim that microplastics are found in mothers’ milk as well. It is important to investigate and find out how microplastic spreads throughout our world, but it is also crucial to be able to detect these microparticles and determine the type of plastic they are made of. There is a standard procedure of detecting and identifying micro particles that are found in water, but there is no standardized process to detect and identify microplastics in soil. The main purpose of this paper was to test methods of separating microplastics from soil using salt solutions and hydrogen peroxide and to evaluate how useful vibrational spectroscopy is for microplastic detection in soil. The main tasks were: 1. To separate microplastic particles from soil using saturated NaCl and KBr solutions and to determine how those solutions affect soil and plastic; 2. To test microplastic and soil separation method using 30 % H2O2 solution and to determine how this solution affects soil and plastic; 3. After conducting experiments for standardizing method of soil and microplastics separation, determine if it is possible to identify the class of microplastic particle vs found in real samples. Separation of microplastics from soil using saturated NaCl solution was successful for HDPE, LDPE, PP and PS particles, partially successful for acrylic fiber and group 7 plastic particles, separation failed for PVC and PET particles. Separation using 30 % H2O2 solution was efficient and proved that the solution breaks down organic matters, which can be removed from sample after selecting right amount of hydrogen peroxide. While using those two separation methods, degradation of microplastics was not visible. Artificial soil and microplastic samples as well as real samples were prepared using mentioned methods. The type of plastic was identified after measuring Raman spectra of retrieved particles. In four of 8 real samples microplastics were found – polypropylene in two of them and polyethylene in other two. This confirms that separating samples with salt solution, H2O2 solution and using Raman spectroscopy is an effective way to detect and identify microplastics in soil. |
