Abstract:The objective of this study was to determine the degrability/biodegradability of disposable plastic bags available on the market that are labeled as degradable/biodegradable and those certified as compost. The investigated materials were obtained from chain stores in the Czech Republic and Poland. Seven kinds of bags (commercially available) were used in this study. One of them was a disposable bag made of HDPE and mixed with totally degradable plastic additive (TDPA additive). Another was a disposable made of polyethylene with the addition of pro-oxidant additive (d2w additive). One was labeled as 100% degradable within various periods of time, from three months up to three years, and four were certified as compostable. The test was carried out in a controlled composting environment. The biodisintegration degree of the obtained pieces was evaluated following a modified version of ČSN EN 14806 Norm ''Packaging -Preliminary evaluation of the disintegration of the packaging materials under simulated composting conditions in a laboratory scale test" and a modified version of ČSN EN ISO 20200 "Plastics -Determination of the degree of disintegration of plastic materials under simulated composting conditions in laboratory-scale test" (ISO 20200:2004). The emphasis was put on determination whether the bags are degradable/biodegradable or not.
Biodegradation of plastics bags advertised as 100%-degradable or certified as compostable was tested in composting conditions. Samples were placed into frames and inserted into one clamp within the compost pile to investigate the biodegradation. The plastics bags were obtained from chain stores in the Czech Republic and Poland. The shopping bags were made of HDPE with the TDPA additive (sample 2), PP with an addition of pro-oxidants (d2w) (samples 1, 3) and materials certified as compostable (starch, polycaprolactone) (samples 4, 5, 6, 7). Control sample (cellulose filtering paper, sample 8) was to check the potential of biological decomposition in the tested environment. At the end of the 12-week experimental period it was found that the polyethylene samples with the additive (samples 1, 2, 3) had not been decomposed, their colour had not changed and that no degradation neither physical changes had occurred (did not biodegrade). Samples certified as compostable (samples 4, 5, 6, 7) were decomposed. The results at the municipal compost facility demonstrate that the compostable plastics biodegrade and polyethylene samples with the additive did not biodegrade in compost.
This work presents the analysis of the influence of compost and reclamation substrate addition and mineral fertilizers application on leaching of mineral nitrogen, microbial activities, soil hydrophobicity and plant biomass production. To demonstrate the effect of compost, reclamation substrate and mineral nitrogen (Nmin) addition on above parameters, the pot experiment was performed. As a model crop, Deschampsia caespitosa L. was used and cultivated for 63 days in climate chamber. The leaching of Nmjn was measured by application of ion exchange discs, soil hydrophobicity was determined based on the values of saturated hydraulic conductivity (Ksat) and microbial activity was expressed as basal (BR) and substrate induced respiration (SIR). Four variants (V1-V4) with different doses of fertilizers were prepared: V1 - control without addition of fertilizers; V2 - this variant of experiment was prepared as mixture of compost and arable land in ratio 7:3; V3 - 90 g/m2 of mineral fertilizers NPK (in the ratio 1:1:1) were applied there and into V4, dose 30 g of compost were applied. The significant differences (P < 0.05) in the detection of Nmin, values of Ksat and SIR were found. The highest decrease of mineral nitrogen leaching was observed by the simultaneous applications of compost (V4) to arable soil, about 50% in comparison with the variant V4 (application of mineral fertilization) and about 10% in comparison with the control. Variants with addition of compost (V2 and V4) showed higher values than variants without, which were measured at three stages (before application of Nmin - 12 days after establishment of the experiment; after application of Nmin - 34 days; at end of the experiment - 63 days). During the experiment, two types of respiration were measured: BR and SIR. The significant differences in SIR were found between variants with addition of compost and variants without. The SIR (cumulative production of CO2) was higher about 25% in variants V2 and V4 compared to variants V1 and V3. The highest values of Ksat were found in variants with addition of compost. Conversely, the lowest value of Ksat was detected in variant with addition of Nmin. Low values of Ksat indicate an increased level of hydrophobicity.
Abstract:The objective of this study was to find out whether the quality of compost would change during the process of composting carrier bags claimed by manufacturers as compostable or biodegradable in terms of parameters stipulated in the standard ČSN 46 5735 Industrial composts. Eight samples were subjected to the composting process in laboratory conditions. The compost samples were analyzed in the accredited laboratory. All samples met parameters stipulated for Class II. Seven samples of the eight met parameters stipulated in the standard ČSN 46 5735 for Class I. The samples had no influence on compost characteristics: strength, content of water and salt, pH value, content of nutrients or proportion of organic substances; other components of the compost remained unchanged. Optical changes of the compost did not occur either.
Production of cast-off tyres and ways of dealing with this waste have been analysed. Possible ways of processing cast-off tyres such as "use as fuel" and "tyre crushing" have been compared in terms of their environmental impacts. The presented research is ecobalance and despite using the knowledge of LCA method, the method itself according to ISO standards is not applied. Use for energy ("use as fuel" process) was assessed as more environmentally efficient, i.e. with lower environmental impacts than "tyre crushing".
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.