Effectiveness of selected issues related to used tyre management in Poland

This paper discusses interactions between the generation, collection and recovery of used tyres while considering an indicator of their mass accumulation per area in Poland. Notably, this study aimed to assess selected issues related to used tyre management efficiency from 2008 to 2018 based on European Union and national regulations. Within 11 years, over 5 million Mg of used tyres was introduced into the domestic market—exceeding the amount required for 50 million registered vehicles. It was demonstrated that a significant tyre waste management process involved the recovery of 47% of all tyres, which was almost entirely correlated with the total volume of tyres. Only the growth trend for generated tyres was considered significant, and the rarely used indicator of the accumulation of used tyres per area exhibited an uneven accumulation of used tyres, with the highest amount being 48.06 Mg km−2 in a region with a small area but a significant volume of waste tyres. Therefore, the management of used tyres requires action in the country to optimally increase this form of waste collection while consolidating the development, gathering and processing infrastructure in the context of further minimising environmental pressure and increasing the efficiency of their use by considering the 4R principle.

Assessing the Biodegradation of Vulcanised Rubber Particles by Fungi Using Genetic, Molecular and Surface Analysis

Millions of tonnes of tyre waste are discarded annually and are considered one of the most difficult solid wastes to recycle. A sustainable alternative for the treatment of vulcanised rubber is the use of microorganisms that can biotransform polymers and aromatic compounds and then assimilate and mineralise some of the degradation products. However, vulcanised rubber materials present great resistance to biodegradation due to the presence of highly hydrophobic cross-linked structures that are provided by the additives they contain and the vulcanisation process itself. In this work, the biodegradation capabilities of 10 fungal strains cultivated in PDA and EM solid medium were studied over a period of 4 weeks. The growth of the strains, the mass loss of the vulcanised rubber particles and the surface structure were analysed after the incubation period. With the white rot fungi Trametes versicolor and Pleurotus ostreatus, biodegradation percentages of 7.5 and 6.1%, respectively, were achieved. The FTIR and SEM-EDS analyses confirmed a modification of the abundance of functional groups and elements arranged on the rubber surface, such as C, O, S, Si, and Zn, due to the biological treatment employed. The availability of genomic sequences of P. ostreatus and T. versicolor in public repositories allowed the analysis of the genetic content, genomic characteristics and specific components of both fungal species, determining some similarities between both species and their relationship with rubber biodegradation. Both fungi presented a higher number of sequences for laccases and manganese peroxidases, two extracellular enzymes responsible for many of the oxidative reactions reported in the literature. This was confirmed by measuring the laccase and peroxidase activity in cultures of T. versicolor and P. ostreatus with rubber particles, reaching between 2.8 and 3.3-times higher enzyme activity than in the absence of rubber. The integrative analysis of the results, supported by genetic and bioinformatics tools, allowed a deeper analysis of the biodegradation processes of vulcanised rubber. It is expected that this type of analysis can be used to find more efficient biotechnological solutions in the future.

Assessing The Biodegradation of Vulcanised Rubber Particles by Fungi Using Genetic, Molecular and Surface Analysis

Millions of tonnes of tyre waste are discarded annually and are considered one of the most difficult solid wastes to recycle. A sustainable alternative for the treatment of vulcanised rubber is the use of microorganisms that can biotransform polymers and aromatic compounds and then assimilate and mineralise some of the degradation products. However, vulcanised rubber materials present great resistance to biodegradation due to the presence of highly hydrophobic cross-linked structures that are provided by the additives they contain and the vulcanisation process itself. In this work, the biodegradation capabilities of 10 fungal strains cultivated in PDA and EM solid medium were studied over a period of 4 weeks. The growth of the strains, the mass loss of the vulcanised rubber particles and the surface structure were analysed after the incubation period. With the white rot fungi Trametes versicolor and Pleurotus ostreatus, biodegradation percentages of 7.5 and 6.1%, respectively, were achieved. The FTIR and SEM-EDS analyses confirmed a modification of the abundance of functional groups and elements arranged on the rubber surface, such as C, O, S, Si and Zn, due to the biological treatment employed. The availability of genomic sequences of P. ostreatus and T. versicolor in public repositories allowed the analysis of the genetic content, genomic characteristics and specific components of both fungal species, determining some similarities between both species and their relationship with rubber biodegradation. Both fungi presented a higher number of sequences for laccases and manganese peroxidases, two extracellular enzymes responsible for many of the oxidative reactions reported in the literature. The integrative analysis of the results, supported by genetic and bioinformatics tools, allowed a deeper analysis of the biodegradation processes of vulcanised rubber. It is expected that this type of analysis can be used to find more efficient biotechnological solutions in the future.

Effectiveness of Selected Issues of Used Tyre Management in Poland

The study aimed to assess used tyre management efficiency in Poland from 2008 to 2018, considering their recovery based on EU and national regulations. Within 11 years, over 5 million Mg of used tyres were introduced to the domestic market, exceeding 50 million registered vehicles. A significant process in tyre waste management was the recovery of 47% of tyres, which was almost fully correlated with the total amount of tyres. Only the growth trend of the manufactured tyres was considered significant, and the rarely used indicator of the accumulation of used tyres per area showed an uneven accumulation of worn tyres with the highest amount of 48.06 Mg km-2 in a region with a small area but significant volume of tyres. Therefore, management of used tyres requires taking actions that optimise increasing waste collection and rational recovery in the context of the further minimisation of environmental pressure and increasing the efficiency of their use, taking into account the advanced technology.

Properties of sand concrete with recycled tyre polymer fibers

Disposal of tyre waste is a major environmental problem in all over of the world. It has been estimated that more than 1.5 billion tyres are produced annually and almost one million end their service life. More than 50% of them are accumulated on landfills. The tyre fiber can be added to the concrete mixture to improve not only the strength properties, but also the crack resistance of the composition. The use of recycled tire polymer fibers as reinforcement component is a perspective view on the development of dispersed concrete technology. In this research the main characteristics of the fiber and the technological characteristics of the concrete mixture are presented. The effect of the polymer fiber on strength and performance properties of sand concrete are shown. It was found that the optimal dosage of fiber is 1 kg/m3, the adding of the fiber reduces at the range 3.6% of slump of the concrete mixture. It was found that each 10 kg/m3 of recycled polymer fiber reduce the density of samples by 4%. The addition of such amount of the polymer fiber reduces the compressive strength. The addition of 1 kg/m3 has the significant effect on the reduction of the compressive and flexural concrete strength with class B15, while the same characteristics of concrete with class B30 are higher. The results of this research allow to conclude that such fiber is suitable to use in concrete with class В30 and lower.