Biodegradability of lubricating oils

Magistritöö Keskkonnakorralduse ja -poliitika õppekavalMaailmas aina suureneva reostuse probleemi tõttu on biolagunevate materjalide kasutuselevõtt üha olulisem. Seetõttu on tähtis uurida ka biolagunevust. Käesoleva magistritöö eesmärk on uurida määrdeõlide biolagunemist ning katsetada kahte erinevat meetodit õli lisamiseks biolagunemise katsesse. Magistritöös uuriti nelja erinevat määrdeõli, mis olid toodetud rapsiõli baasil tehnilisel eesmärgil kasutamiseks. Määrdeõlide lagunemist katsete käigus võrreldi toiduõli lagunemisega. Õlide biolagunevuse uurimiseks viidi läbi biolagunemise katsed mis põhinesid mikroorganismide hapnikutarbe mõõtmisel vastavalt rahvusvahelisele standardmeetoodikale OECD 301F. Katsete tulemustest selgus, et taastuval taimsel toorainel põhinevate määrdeõlide lagunemine 10-päeva jooksul jäi vahemikku 41‒ 75%. Katseperioodi lõpuks oli lagunenud 62‒97% katsetesse lisatud õlist. Kergesti biolagunevaks klassifitseerimisel nõutud biolagunemise määr 60% 10-päevase lagunemisaja jooksul saavutati ühe määrdeõli korral (õli 4). Antud magistritöö tulemustest selgus, et kahe õlide pudelitesse lisamise meetodi vahel ei esinenud olulist erinevust. Seetõttu ei saa järeldada, et üks katsetatud kaalumise meetod oleks teisest variandist parem.Due to the ever-increasing problem of pollution in the world, the introduction of biodegradable materials is becoming increasingly important. Therefore, it is important to study biodegradability as well. The aims of this master's thesis is to study the biodegradation of lubricating oils and to test two different methods of adding oil to the biodegradation test. In the master's thesis four different lubricating oils, which were produced on the basis of rapeseed oil for technical use, were studied. The degradation of lubricating oils during the tests was compared to the degradation of cooking oil. In order to study the biodegradability of oils, biodegradability tests were performed based on measuring the oxygen consumption of microorganisms according to the international standard methodology OECD 301F. The results of the biodegradation tests revealed that the degradation of lubricating oils within a 10-day was between 41‒75%. By the end of the test period, 62‒97% of the oil added to the tests had degraded. The biodegradation rate of 60% during the 10-day decomposition period required for classification as easily biodegradable, was achieved in case of one tested lubricating oil (oil 4). The results of this master's thesis revealed that there was no significant difference between the two methods of adding oils to the bottles. Therefore it cannot be concluded that one of the tested weighing methods is better than the other