Evaluation of the degradation of plastics PET and PE type under composting conditions using coffee pulp as substrate

doi:10.21203/rs.3.rs-2741487/v1

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Evaluation of the degradation of plastics PET and PE type under composting conditions using coffee pulp as substrate

https://doi.org/10.21203/rs.3.rs-2741487/v1

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The indiscriminate use, the alarming accumulation of plastic, and its subsequent poor well-disposal and management have generated the current environmental problem. As an environmentally friendly and effective strategy, composting processes arise like a method for waste treatment. This study explored the degradation of polyethylene terephthalate (PET) and low-density polyethylene (PE) plastic types under composting conditions for 90 days using coffee pulp as substrate into the compost. The degradation was estimated from weight variation over time, the thermal stability of the PET and PE samples was carried out using thermogravimetric analysis (TGA/DTA) whereas the chemical and morphological changes on the samples were assessed by FT-IR and SEM. The bacterial communities of composting were also investigated by 16S rRNA gene clone analysis. The results showed a partial degradation of PET and PE samples under composting conditions for the period of time considered. However, a strong adhesion effect was observed for PE samples which give place to a variation on the thermal stability of the samples. 16S RNA gene clone analysis showed that Sphingobacterium was the dominant bacteria, which is not related with the degradation of plastic material on composting. This result could be related with a reduced degradation during the composting treatment.

degradation

composting

PET

coffee pulp

The versatility of the mechanical and thermal properties of plastics have become in an essential product in the modern life around world[1], [2] not only due to their cheap manufacturing, stability, and durability but also to their extensive and wide variety of applications. Because of these advantages, the plastic production has raised progressively since 1950s achieving 367 Mt in 2020, according to the report of Plastics Europe [3], [4]. The most manufactured plastics are used in packaging as bottles and bags of short live products resulting in a huge consumption of single use plastics, which are discarded easily [4],[5]. The significant amount of the plastics generated from these actions lead to the accumulation of plastic waste in the environment and landfills of million tonnes of plastic [2][6],[7]causing devastating environmental pollution which affects ecosystems, wildlife, and human health in addition to waste management problems [2],[4][5], [8]. Among those, the most common types of plastics polluting and accumulated as solid waste in the environment are polyethylene terephthalate (PET), polypropylene (PP), polyethylene (LDPE-HDPE), vinyl chloride (PVC), polyurethane (PU) and polystyrene (PS). All of them are characterized by high durability and resistant to degradation in environmental conditions [5]. The serious problem of plastic pollution has generated a wake-up call for searching effective and friendly alternatives for the treatment of plastics with the aim to reduce their impact on the environment, alleviate disposal problems and achieve their sustainability [4],[9]. In recent years, a promising alternative for the solid waste management by composting processes has emerged as an attractive option to the conventional recycling process (such as incineration) which generate toxic compounds released in the air and low heat efficiency due to its high moisture content [10]. The composting strategy can reduce the impact of the plastic at the end of its useful life, mainly when it comes to plastic products which are most likely mismanaged or whose recycling is not feasible, as those used for packaging (PET and PE). Furthermore, the decrease of the plastic environmental impact through this treatment process help to reduce the use of the fossil resources and encourages their integration into natural cycles [4]. On the other hand, reducing the waste stream to landfills saves energy and allows to valorize some organic compounds with high content of nutrients and microorganisms from agricultural processes[11] as coffee pulp in coffee processing sector, which represents about 44.0% of beans in a wet base. In Colombia, coffee production represents 85% of the country's agricultural production. In coffee processing, only 9.5% of the total weight of the coffee bean is an exploited product for consumption in the preparation of beverages, and 90.5% are by-products of the pulping, which are considered waste that does not have a well-disposal and management and have become in contaminants of soils and water resources [12]. The coffee pulp production in Colombia is approximately 2.25 million tons per year [13]. In this way, the composting process arises up as a potential alternative to take advantage the microbiological value of the coffee pulp and to get its valorisation within of the coffee production chain as well as to mitigate the pollution effects as by-product by being an efficient and cost-effective biological process for treating waste [14], [15].

Therefore, the goal of this work is to contribute to the knowledge of alternative strategies for solid waste management to reduce the serious environmental impact of plastics and take advantage of agricultural waste for the composting processes. Thereby, this study was carried out to evaluate the degradation capacity of PET and PE plastics over time under composting conditions at the laboratory-scale using coffee pulp as substrate. The samples were subjected to physical (weight), structural, morphological, and thermal analysis. In addition, the bacterial community of the compost was examined by 16S rRNA gene clone analysis to identify the principal microorganisms that affect the composting processes and the degradation of plastics.

Materials

The degradability of the PET and PE plastics type under aerobic composting conditions in the laboratory scale was performed. PET samples were mainly disposable plastic bottles (soda and water drink bottles), and PE samples were packaging small bags obtained from a solid waste collection point within the Universidad Católica de Manizales (UCM). The samples of both plastics were cleaned and kept dried. The PET samples were cut into sizes of 3 cm x 3 cm squares with an approximate weight of 0.3820 g in each piece, whereas the PE samples were pieces of 9 cm x 9 cm with a weight of 0.4220 g. Every piece of plastic samples was rigorously measured in such a way that weight only varied in the last significant digit (relative error of ± 1×10^− 4 g). These samples conditions were in accordance with ISO 20200:2015 [16].

The coffee pulp and soil used as a substrate for compost were obtained from a rural area (municipality of Neira) near to Manizales in the Central-West of Colombia. The coffee pulp was pre-treated by drying at room temperature for 5 days and deposited on an aluminium container to be dried in an oven at 60°C for 13 hours to reduce the water content on the organic matter previous composting treatment.

Composting

The compost was prepared mixing a 30% of dry mass of coffee pulp and 35% of soil with a sawdust (20%), fresh and dry organic matter (7%) and Urea (1%). The compost was deposited in Polyvinyl Chloride (PVC) reactors (20 cm x 30 cm x 10 cm) with a small hole (made home) for ventilating the samples. Each reactor was loaded with a total mass of 1 Kg of compost and each plastic system was conducted in quadruplicate (R1, R2, R3 and R4) to evaluate the effect of composting conditions on its degradation using coffee pulp as a substrate. On the compost, 18 pieces of PET and PE samples (labelled) were located and covered with it. An image of one of the reactors set for the experiment is shown in Fig. 1. The reactors of both plastic systems were kept in a controlled environment at an average temperature of 58.0°C (± 1.0°C) in an oven. To investigate the degradation process on the plastic samples as a function of time, they were taken out from each of the reactors every five days, placed in a desiccator, and they were weighed after 48 h at room temperature. This process was repeated over all experimental period (90 days). The reactors also were weighed every five days to determine water loss by evaporation. When the lost was up to 50%, they were recovered with distilled water using a fine spray until the weight at the beginning of the experiments.

Characterization Of The Samples

The weight variation of treated samples was calculated according to the relationship:

W (mg) = m_D0-m_DT, where m_D0 corresponds to initial mass of the samples, and m_DT denotes the measured mass of the dried samples after the composting treatment during a certain period of time which was specified by T days. That is to say, m_D5 denotes the weight of the sample maintained in compost conditions for 5 days. The results are expressed as an average weight determined for four replicates for the same treatment time.

ATR-FTIR spectra were collected on FTIR spectrometer equipped with a PIKE MIRacle single reflection ATR accessory. The spectra were measured with a resolution of 4 cm^− 1 in the range of 4000 − 400 cm^− 1 (64 scans).

The evaluation of thermal stability of the samples was carried out using a TQ-500 apparatus from TA Instruments under air atmosphere. The sample were examined from 50 to 600°C with a heating rate of 10 K/min.

The surface morphology of PET and PE samples before and after testing was observed by SEM-JSM 6301 model. The dried samples were imaged at high vacuum at 1.0 kV and WD 6.0 mm.

The Microbiological Analysis For 16s Rdna

The ADN extraction from the compost containing coffee pulp was performed using a NORGEN kit with stool DNA isolation kit according to the manufacturer’s instructions. After extraction process, DNA was quantified by the nanodrop spectrophotometer method and separately stored at -20°C for subsequent sequencing according to Illumina MiSeq platform. The extracted DNA were used for experiments of microbial diversity (Metataxonomic) for bacteria with 16S r RNAV3-V4 variable region using oligonucleotides 341F (CCTACGGGNGGCWGCAG) and 805R (GACTACHVGGGTATCTAATCC). The sequencing was run on a MiSeq machine for 2 x 300 bp paired-ends sequencing (Illumina). The diversity, abundance and community structure of bacteria were studied with last version of MOTHUR platform.

Statistical analysis

The weight variation on the processed samples under composting conditions during the treatment time (90 days) was analysed with an experimental design of repeated measures using a Mauchly test, previous verification of the Huynh-Feld condition on the response of the variances. The sample size as experimental units were four (Reactors: R1, R2, R3 and R4) for each plastic system (PE and PET) with 18 samples over time. The data were divided in four series (S1..S4) with a set of five weight measures at different times; S1: D5,D10, D15, D20 and D25, S2: D25, D30, D40, D45 and D50, S3: D50, D55, D60, D65 and D70, S4: D70, D75, D80, D85 and D90. These data were analysed independently with an intra-subject effect test to determine variances of the weight on the samples over time. Also, the data were subjected to intra-subject contrast test (polynomial contrast) to know the trend on the weight measures as a function of time, where time represents a quantitative factor and plastic system acts as qualitative factor. Finally, an inter-subject effect test was applied to the weight data to contrast the effect of the plastic type on the measures. All the data was analysed with a significance P value < 0.05 using SPSS software.

The experiments to determine the weight loss of the treated PET and PE samples under composting conditions are summarized in Fig. 2 (a) and (b), respectively. The samples were recovered every five (5) days from the compost incubated at 58.0 ± 1.0°C. The weight loss in the samples at each specific time was calculated with respect to the weight of the initial samples (D0). A statistically significant change in the weight loss for the treated PET samples at 25 days (D25) was observed. The results indicated a progressive gain of weight on the samples from D15 to D25. This fact could be related with an adhesion of the compost material on the surface of the samples, which is unlikely given by a change in the physical parameters of the compost (temperature fluctuations or increased humidity). However, this effect was not noticed in the samples at longer treatment (incubation) times (D30 to D90), where no statistically significative changes in the weight were observed.

In the case of treated PE samples, the statistical analysis did not reveal any effect on plastic degradation over treatment time. The results showed that the composting conditions with a coffee pulp as substrate had no significant effect on the degradation of the plastics over the total time evaluated in this study (90 days). The degradation processes under composting conditions are influenced by factors not only include the physicochemical characteristics of the plastics under study, as their molecular structure, molecular weight, degree of crystallinity and melting temperature of polymer but also own factors in terms of the variation of the soil, organic and inorganic compositions of the compost employed as well as the types of degrading microbiota and the incubation temperature [2].

Some previous studies on polymer degradation of PET and PE under natural and composting conditions have not evidenced a significant degradation of the plastics[1], [11], [17], [18] The effect of biodegradable materials as PLA, PHB or TPS in the recycling process of PET was studied by Aldas et al.[18] Their results showed that these biodegradable polymers had not effect on the degradation of PET under the composting conditions used in that case. On the contrary, the presence of PET interferes with the degradation process of the biodegradable polymers under composting conditions, observed by thermogravimetric analysis, since the degradation temperature of the blends decreased only a few degrees and the samples did not show a significant weight loss after 30 days of treatment. On the other hand, a study of the biodegradable kinetics of PE under controlled composting conditions evidenced that the surface of PE and PE/starch remained unchanged after the treatment [11], [19]. These observations showed that the study of weight loss alone is insufficient to determine the degradation degree of plastics. Thereby, the evaluation of the physicochemical and structural properties by using other characterization techniques as FT-IR, SEM or TGA enable to identify specific behaviour that is only evidenced in detail through those techniques, and it will elucidate changes in the plastic samples subjected to composting treatment [20]. On the other hand, to understand how degradation processes of the plastic considered non-degradable occur under composting conditions, the determination of the parameters and conditions of the compost, nature, and environment where composting happen are relevant factors to get an effective process of degradation or disintegration of the plastics without a pre-treatment.

A detailed FT-IR analysis of the treated samples allowed us to assess the effect of composting conditions as a function of time, checking the variation in the intensity and position of the bands assigned to the vibrations of the functional groups of PET and PE samples [21]. The FT-IR spectra for PET at different time of composting are shown in the Fig. 3 (a). As can be seen, there are no appreciable changes in the spectra of treated samples of PET in comparison with the initial plastic material. So, the intense band at around 1714 cm^− 1 is associated to strong carbonyl bond stretching of -C = O group[22], [23] whereas the broad and intense bands at 1240 cm^− 1 and 1095 cm^− 1 are assigned to the typical stretching vibrations of ether C–O–C[22] and esther[23], [24] bonds, respectively. The C—C stretching aromatic bonds appeared at a wavenumber of 1409 cm^− 1 [25], while the band of low intensity at 1338 cm^− 1 is associated to wagging of the ethylene units[22]. At lower wavenumbers, the FT-IR spectra showed an intense band at 1017 cm^− 1 that can be assigned to C-H aromatic ring in plane bending[24] The band at 970 cm^− 1 have been assigned to -C-C- and -C = C- bonds[26] or to -O-CH₂- stretching of ethylene glycol segments [27]. The bands at 871 and 846 cm^− 1 are attributed to out of plane bending of C-H aromatic ring[28] and rocking bending of C-H bonds of –CH₂- [29], respectively, whereas the band at 723 cm^− 1is assigned to the aromatic in-phase -C-H- out-of- plane bend [22], [23], [30].

The FT-IR spectra of treated PE samples shown in Fig. 3 (b) did not reveal significant changes in their bands as a function of the treatment time. The spectra present the following main transmittance bands at 2914 and 2848 cm^− 1 correspond to the C-H stretching vibrations bonds, the bands at 1471 and 719 cm^− 1 are associated to the bending and rocking vibration, respectively, of the -CH₂- bonds in the polymer [23], [31]. The fact that PE samples treated under composting conditions showed a similar behaviour to that observed in treated PET samples indicated that no significative chemical changes took place owing to the treatment.

The thermal stability and decomposition of the samples were evaluated by TG/DTA at different treatment times. The TG/DTA curves and the degradation temperatures for PET and PE samples during composting treatment over time are shown in Fig. 4 (a) and (b), respectively. The PET samples undergoes two stages of degradation, the first one with a maximum around 418°C and a weight loss of 83.0% due to the thermal degradation of the PET backbone owing to the random scission of ester links in the main chain with the formation of different oligomers, and a second one at 547°C with a weight loss of 17.0% [18], [32]–[34]. All treated PET samples under composting conditions showed a similar trend in the thermogravimetric analysis. This indicates that the thermal stability of the treated PET samples was inappreciably affected for the composting treatment. Similar results were also reported by Girija et al.[33] who investigated the thermal and mechanical properties of PET blends with various natural polymers like starch or cellulose derivatives compounds and they found that there were no significant changes in the decomposition temperature of PET in the blends.

However, in the case of treated PE samples, the thermogravimetric analysis showed different behaviours for thermal degradation of this polymer as a function of time under composting conditions in contrast with those of PET. The thermal degradation mostly occurred in four stages on PE samples as can be seen in Fig. 4(b). For the initial sample (D0), the maximum degradation rate took place at 357°C with a weight loss of 38.0%, followed by a second stage at 380°C with a weight loss of 25.0%, the third one at 449°C with a weight loss of 28.0%, and a last one around of 533°C with a weight loss of 9%. For the treated PE sample at 20 days (D20), the main decomposition took place in the second stage at 341°C and a weight loss of 37%. For this sample, the thermal degradation happened at lower temperatures than no-treated PE sample (D0). As composting time increase, for example D60 and D90 samples, the higher thermal degradation occurred in the first stage as in D0, at 358°C and 359°C and a weight loss of 57% and 69%, respectively.

These differences between the thermal behaviour of treated PET and PE samples could be due to the chemical structure of PE used for packaging (low-density polyethylene, LDPE). Its less compact structure with a lot of branches [35] gives place to a random and distinct interactions of the plastic with the surrounding environment. As a consequence of these interactions, the polyethylene decomposes and results in a random distribution of volatile matters which contain not only different hydrocarbons but also organic residues and microorganisms from the compost. This consideration agrees with the higher thermal stability against degradation observed for treated PET samples under composting conditions, since PET plastic has a higher degree of polymerization than PE plastic [36], [37]

The effect of the composting process on PET and PE samples was monitored by SEM images and by digital photos to analyse and to detect changes in the morphology as a function of the treatment time The digital photos of the surface appearance of treated PET samples are shown Fig. 5 (insets). As can be seen, the samples lost stiffness as the treatment time increase. The plastic samples began to curve at 20 days (D20), and this change in the appearance was more evident at 90 days (D90) of treatment under composting conditions. On the other hand, after 30 days of composting, the treated PET samples evidenced some brown areas on their surface. This result would be related to the adhesion of the organic matter from the compost to the surface of the samples, which increased at long treatment times (D90). The SEM images of the surfaces showed a uniform and smooth aspect until the sample D20 of composting. However, from D30 to D90 horizontal and vertical stripes were observed, as well as a change in the surface roughness of the plastic, which could probably also be a consequence of the adhesion of the compost on the surface of the samples, as it has been mentioned above. Furthermore, this effect of composting observed by microscopy agrees with the fact that D30 showed an increase in its weight, according to Fig. 2(a), which would highlight that the adhesion of the compost on the surface of the plastic could hide or reduce the response of the polymer to the degradation process. At the end of the treatment time, samples D80 and D90, a layer of compost can be observed on the surface. This observation well-coincides with tonality changes and the appearance of brown spots on the surface of the plastic.

The appearance and morphologic changes in treated PE samples are shown in Fig. 6. In this case, the effect of the composting on the surface of the samples was exhibited early than for treated PET samples. The surface of the samples became rough from 10 days of treatment (D10), and random stripes and adhesion of compost on the surface took place at an early stage in the process. Other significant changes in the appearance of the PE samples were the changes in the tonality towards brown colour on most of the samples, like what happened in treated PET samples. From the above observations in appearance and surface morphology changes it may be concluded that the treated PE and PET samples remained unchanged. They did not exhibit changes related to degradation after composting treatment such as erosion on them, which would indicate that they were not attacked by the microorganisms under the composting conditions established in this study. These results are consistent with FT-IR and weight loss analysis which evidenced that the degradation of PE and PET was negligible[11], [38]. Furthermore, the adhesion observed by microscopy (SEM) was in good agreement with thermogravimetric analysis over testing time. It is necessary to point out that the variation of the weight loss on these samples would be related with the amount of compost attached on the surface under composting conditions. The negligible weight loss of PE samples as a function of composting time, displayed in the Fig. 2(b), the physical characteristics of this plastic and the difference on the surface area in contact with the compost, would cause this effect (compost adhesion) to appear in an early stage of the treatment in comparison with those of PET.

Microbiological Analysis Of Compost

The 16S rRNA gene clone analysis was used to identify the bacterial community in compost containing coffee pulp as substrate, that was used for the composting processes of PET and PE samples after 90 days. The classification analysis and relative abundance of bacteria at the phylum, family, and genus levels (taxonomic groups in the classification of organisms) are shown in Fig. 7. As can be seen, Proteobacteria, Bacteriodota, Actinobacteriota, Firmicutes, Chloroflexi and Myxococcota were the six most dominant phylum in the compost samples. Between them, Proteobacteria and Bacteroidota were the most abundant phylum with around 55.0%, whereas Myxococcota only contribute with a 1.0% of the bacterial content in the compost.

In terms of family, the analysis of the relative abundance revealed that Sphingobacteriaceae was the most abundant family, with a 21.0% of the total bacterial 16S r RNA sequence, followed by Rhizobiaceae, Streptosporangiaceae and Flavobacteriaceae which contributed to 9.0% each to the bacterial population in the compost.

Lastly, Planococcaceae and Bacillacea have the lower proportion on the composition of bacterial communities. Sphingobacterium (∼20.0%) and Nonomuraea (10.0%) comprised the main genera bacterial composition in the compost.

In a previous paper has been reported that the Proteobacteria, Firmicutes and Actinobacteria are the most abundant phyla bacterial communities found during composting processes[39] as in the findings of this research. However, it has been reported that species belonging to the genera, like Pseudomons, Ralstonia, Stenotrophomonas, Klebsiella, Acinetobact, Rodococcus, Staphylococcus, Streptococcus, Stretomyces and Bacillus, are able to degrade some types of PE [1], [4], [10], [14], [40]. However, they were not found in the compost medium employed in this study for PET and PE samples. Some of these bacterial communities were also found in the microbial structure sequencing during spontaneous coffee-bean fermentation process in Colombia [41]. Therefore, the lack of this kind of the bacterial communities in the compost after composting processes of PET and PE samples could be related with their negligible degradation and disintegration, considering that composting physical conditions like humidity and temperature play a crucial role not just for degradation of polymer materials, influenced by the nature of each plastic, but also for effective action of the microorganisms present in the compost [1], [11], [38], [40], [42]. On the other hand, it has been reported that the growth of microbial community controlled under certain laboratory conditions (constant abiotic conditions) of temperature, humidity, and aeration, can have a grave impact on the activity of the microorganism for the degradation processes of plastics [40]. Thereby, to determine the nature of the environment where the process occurs will allow to control and fit the best conditions to reach it and guarantees more reproducible results.

The nature of PET and PE plastics as well as the composting conditions (microbial communities present) influenced the degradation process under the experimental conditions applied in this study. The weight variation tracking during 90 days of composting treatment did not evidence statistically significant changes, that suggested a degradation because of the composting process. However, the thermal and morphological characterization of the PE samples showed an important effect on the thermal stability and surface appearance due to a compost adhesion effect from early stage of composting, in contrast with the results of PET samples which remained mostly unchanged.

On the other hand, the bacterial community of the compost determined by 16S rRNA gene clone analysis did not have a significant effect on the degradation process of the PET and PE plastic samples.

Declaration of Competing Interest

The authors declare that they have no competing interests.

Acknowledgment

Authors acknowledge to the Directorate of Research and Graduate Studies of the Universidad Católica de Manizales through the agreement No. 027 on March 25^th of 2021 and to Ministerio de Ciencia e Innovación through the Project PID2019-108552GB-100 for financial support Also, we would like to express our gratitude to Prof. Dr. Julien Bachmann, Chair of Chemistry of Thin Film Materials, for his funding support for the internship of the students Ms. Mariana Dussán and Mr. Andrés García and facilitate the SEM and FTIR characterizations necessary for this research project. The assistance of Nastasiya Yuriychuk with TGA analysis of the samples was also acknowledged.

Author contributions

Material preparation and data collection were performed by MD and AAGV. Conception, funding acquisition, writing, formal analysis, editing, visualization was performed by CVRM. The first draft of the manuscript was written by CVRM. MLG reviewed, wrote, and commented on previous versions of the manuscript. All authors approved the final manuscript.

Data availability Statement

The authors declare that the data supporting the findings of this study are available within the paper, and data sets generated during the current study are available from the corresponding author on reasonable request.

Ghatge S, Yang Y, Ahn JH, Hur HG (2020) Biodegradation of polyethylene: a brief review. Appl Biol Chem. https://doi.org/10.1186/s13765-020-00511-3
al Hosni AS, Pittman JK, Robson GD (2019) Microbial degradation of four biodegradable polymers in soil and compost demonstrating polycaprolactone as an ideal compostable plastic. Waste Manage. https://doi.org/10.1016/j.wasman.2019.07.042
Plastics-the Facts 2021 An analysis of European plastics production, demand and waste data (2021) Plastics Europe Enabling a sustainable future. https://plasticseurope.org/knowledge-hub/plastics-the-facts-2021/
Quecholac-Piña X, Hernández-Berriel MDC, Mañón-Salas MDC, Espinosa-Valdemar RM, Vázquez-Morillas A (2021) Degradation of plastics in simulated landfill conditions. Polymers. https://doi.org/10.3390/polym13071014
Quecholac-Piña X, Hernández-Berriel MDC, Mañón-Salas MDC, Espinosa-Valdemar RM, Vázquez-Morillas A (2020) Degradation of plastics under anaerobic conditions: A short review. Polymers. https://doi.org/10.3390/polym12010109
Leejarkpai T, Mungcharoen T, Suwanmanee U (2016) Comparative assessment of global warming impact and eco-efficiency of PS (polystyrene), PET (polyethylene terephthalate) and PLA (polylactic acid) boxes. J Clean Prod. https://doi.org/10.1016/j.jclepro.2016.03.029
Gironi F, Piemonte V (2011) Life cycle assessment of polylactic acid and polyethylene terephthalate bottles for drinking water. Environ Prog Sustain Energy. https://doi.org/10.1002/ep.10490
Ahmed W, Staley C, Kaiser T, Sadowsky M, Kozak S, Beale D, Simpson S (2018) Decay of sewage-associated bacterial communities in fresh and marine environmental waters and sediment. Appl Microbiol Biotechnol. https://doi.org/10.1007/s00253-018-9112-4
Sintim HY, Bary AI, Hayes DG, Wadsworth LC, Anunciado MB, English ME, Bandopadhyay S, Schaeffer SM, DeBruyn JM, Miles CA, Reganold JP, Markus F (2020) In situ degradation of biodegradable plastic mulch films in compost and agricultural soils. Sci Total Environ. https://doi.org/10.1016/j.scitotenv.2020.138668
Nagao N, Watanabe K, Osa S, Matsuyama T, Kurosawa N, Toda T (2008) Bacterial community and decomposition rate in long term fed-batch composting using woodchip and Polyethylene terephthalate (PET) as bulking agents. World J Microb Biot. https://doi.org/10.1007/s11274-007-9625-y
Leejarkpai T, Suwanmanee U, Rudeekit Y, Mungcharoen T (2011) Biodegradable kinetics of plastics under controlled composting conditions. Waste Manage. doi: https://doi.org/10.1016/j.wasman.2010.12.011
Cortés YF, Rodríguez KDS, Marín LAV (2020) Environmental impacts from coffee production and to the sustainable use of the waste generated. Produccion y Limpia. https://doi.org/10.22507/PML.V15N1A7
Carvajal-Flórez E, Oakley SM (2022) Coffee pulp characterization and treatment as adsorbent material for heavy metal removal from landfill leachates. Int J of Environ Sci Te. https://doi.org/10.1007/s13762-022-04557-2
Watanabe K, Nagao N, Toda T, Kurosawa N (2009) The dominant bacteria shifted from the order ‘lactobacillales’ to bacillales and actinomycetales during a start-up period of large-scale, completely mixed composting reactor using plastic bottle flakes as bulking agent. World J Microb Biot. https://doi.org/10.1007/s11274-008-9952-7
Aguilar DLG, Miranda JPR, Muñoz JAE, Betancur PJF (2019) Coffee pulp: A sustainable alternative removal of Cr (VI) in wastewaters. Processes. https://doi.org/10.3390/pr7070403
Norma Española (2016) Plásticos: Determinación del grado de desintegración de materiales plásticos bajo condiciones de compostaje simuladas en un ensayo de laboratorio, ISO 20200:2015. www.aenor.es
Davis G, Bulson H, Harrison D, Billett E (2003) The performance of degradable polymer bags. Macromol Sy. https://doi.org/10.1002/masy.200350724
Aldas M, Pavon C, De la Rosa-Ramírez H, Ferri JM, Bertomeu D, Samper MD, López-Martínez J. (2021) The Impact of Biodegradable Plastics in the Properties of Recycled Polyethylene Terephthalate. J Polym Environ. https://doi.org/10.1007/s10924-021-02073-x
Davis G, Read A, Bulson H, Harrison D, Billett E (2004) Open windrow composting of polymers: An investigation into the rate of degradation of polyethylene. Resour Conserv Recy. https://doi.org/10.1016/S0921-3449(03)00086-7
Alvarez-Vega C, Streitwieser DA, Álvarez-Barreto J, Leon-Reyes A (2022) Characterization of low-density polyethylene greenhouse films during the composting of rose residues. SN Appl Sci. https://doi.org/10.1007/s42452-022-05155-0.
Mark J (2006) Physical Properties of Polymers Handbook Second Edition. Springer, Ohio.
Mohsin MA, Abdulrehman T, Haik Y (2017) Reactive Extrusion of Polyethylene Terephthalate Waste and Investigation of Its Thermal and Mechanical Properties after Treatment. Int J Chem Eng. https://doi.org/10.1155/2017/5361251.
Jung MR, Horgen FD, Orski SV, Rodriguez V, Beers KL, Balazs GH, Jones TT, Work TM, Brignac KC, Royer SJ, Hyrenbach KD, Jensen BA, Lynch JM (2018) Validation of ATR FT-IR to identify polymers of plastic marine debris, including those ingested by marine organisms. Mar Pollut Bull. https://doi.org/10.1016/j.marpolbul.2017.12.061.
Kugo K, Kitaura T, Nishino J (1992) “FT-IR-ATR Analysis of Polycarbonate/Poly(ethylene) terephthalate Blends. Kobunshi Ronbunshu. https://doi.org/10.1295/koron.49.327
Ravichandran SA, Rajan VP, Aravind PV, Seenivasan A, Prakash DG, Ramakrishnan K (2016) Characterization of Terephthalic Acid Monomer Recycled from Post-Consumer PET Polymer Bottles. Macromol Sy. https://doi.org/10.1002/masy.201400269
Kormunda M, Pavlik J. (2010) Characterization of oxygen and argon ion flux interaction with PET surfaces by in-situ XPS and ex-situ FTIR. Polym Degrad Stabil. https://doi.org/10.1016/j.polymdegradstab.2010.05.003
Holland BJ, Hay JN (2002) The thermal degradation of PET and analogous polyesters measured by thermal analysis-Fourier transform infrared spectroscopy. Polymer. https://doi.org/10.1016/S0032-3861(01)00775-3
Hu Y, Wang Y, Zhang X, Qian J, Xing X, Wang X (2020) Synthesis of poly(ethylene terephthalate) based on glycolysis of waste PET fiber. J Macromol Sci A. https://doi.org/10.1080/10601325.2019.1709498
Kinoshita R, Teramoto Y, Nakano T, Yoshida H (1992) Thermal Degradation of Polyesters by simultaneous TG-DTA/FT-IR Analysis. J Ther Analysis. https://doi.org/10.1007/BF01974683
Jiang Z, Guo Z, Zhang Z, Qi Y, Pu C, Wang Q, Jia Z, Xiao C (2019) Preparation and properties of bottle-recycled polyethylene terephthalate (PET) filaments. Text Res J. https://doi.org/10.1177/0040517518767146
Durgun H, Bayram G (2005) Improvement of adhesion between poly(ethylene terephthalate) and polyethylene. J Adhes Sci Tech. https://doi.org/10.1163/1568561054352559.
Dimitrov N, Krehula LK, Ptiček Siročić A, Hrnjak-Murgić Z (2013) Analysis of recycled PET bottles products by pyrolysis-gas chromatograph. Polym Degrad Stab. https://doi.org/10.1016/j.polymdegradstab.2013.02.013
Girija BG, Sailaja RRN, Madras G (2005) Thermal degradation and mechanical properties of PET blends. Polym Degrad Stab. https://doi.org/10.1016/j.polymdegradstab.2005.03.003
Özsin G, Kılıç M, Apaydin-Varol E, Pütün AE, Pütün E (2020) A thermo-kinetic study on co-pyrolysis of oil shale and polyethylene terephthalate using TGA/FT-IR. Korean J Chem Eng. https://doi.org/10.1007/s11814-020-0614-2
Zheng Y, Tao L, Yang X, Huang Y, Liu C, Zheng Z (2018) Study of the thermal behavior, kinetics, and product characterization of biomass and low-density polyethylene co-pyrolysis by thermogravimetric analysis and pyrolysis-GC/MS. J Anal Appl Pyrol. https://doi.org/10.1016/j.jaap.2018.04.001
Garba MU, Inalegwu A, Musa U, Aboje AA, Kovo AS, Adeniyi DO (2018) Thermogravimetric characteristic and kinetic of catalytic co-pyrolysis of biomass with low- and high-density polyethylenes. Biomass Conv Bioref. https://doi.org/10.1007/s13399-017-0261-y
Zaker A, Chen Z, Zaheer-Uddin M, Guo J (2021) Co-pyrolysis of sewage sludge and low-density polyethylene – A thermogravimetric study of thermo-kinetics and thermodynamic parameters. J Environ Chem Eng. https://doi.org/10.1016/j.jece.2020.104554
Singh S, Shankar S, Shikha S (2021) Evaluation of LDPE degradation under controlled composting. Nat Env Poll Tech. https://doi.org/10.46488/NEPT.2021.V20I03.041
Awasthi MK, Zhang Z, Wang Q, Shen F, Li R, Li D, Ren X, Wang M, Chen H, Zhao J (2017) New insight with the effects of biochar amendment on bacterial diversity as indicators of biomarkers support the thermophilic phase during sewage sludge composting. Bioresource Technol. https://doi.org/10.1016/j.biortech.2017.04.100
Vaverková M, Adamcová D, Kotrchová L, Merna J, Hermanová S (2018) Degradation of pet copolyesters under real and laboratory composting conditions. J Mater Cycles Waste Manag. https://doi.org/10.1007/s10163-017-0595-3.
de Oliveira Junqueira AC, de Melo Pereira GV, Coral Medina JD, Alvear MCR, Rosero R, de Carvalho Neto DP, Enriquez HG, Soccol CR (2019) First description of bacterial and fungal communities in Colombian coffee beans fermentation analysed using Illumina-based amplicon sequencing. Sci Rep. https://doi.org/10.1038/s41598-019-45002-8.
Watanabe K, Nagao N, Toda T, Kurosawa N (2010) Bacterial communities in various conditions of the composting reactor revealed by 16S rDNA clone analysis and DGGE. In: Singh, O., Harvey, S. (eds) Sustainable Biotechnology. Springer, Dordrecht.

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Evaluation of the degradation of plastics PET and PE type under composting conditions using coffee pulp as substrate

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Abstract

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Introduction

Materials And Methods

Materials

Composting

Characterization Of The Samples

The Microbiological Analysis For 16s Rdna

Statistical analysis

Results And Discussion

Microbiological Analysis Of Compost

Conclusions

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References

Additional Declarations

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