Microbial degradation of low density polyethylene (LDPE): A review

Sen, Sudip Kumar; Raut, Sangeeta

doi:10.1016/j.jece.2015.01.003

Cited by 311 publications

(83 citation statements)

References 105 publications

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“…Several studies on polymer weathering have used mechanical properties tests to measure the degree of weathering achieved. Recently, studies have focused on the potential for effective biodegradation of PE (Restrepo-Flórez et al, 2014;Kumar Sen and Raut, 2015).…”

Section: Discussionmentioning

confidence: 99%

“…Weight loss of almost 40% has been observed in plastics buried in soil (Accinelli et al, 2012), while Müller et al (2012) estimated degradation rates between 3 and 9% for biodegradable bags in simulated sea turtle gastrointestinal conditions. Microorganisms have also been used for the biodegradation of weathered plastics (Shah et al, 2008), including polyethylene (Artham et al, 2009;Restrepo-Flórez et al, 2014;Kumar Sen and Raut, 2015).…”

Section: Introductionmentioning

confidence: 99%

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Microplastics Generation: Onset of Fragmentation of Polyethylene Films in Marine Environment Mesocosms

et al. 2017

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The fragmentation of high-density polyethylene (HDPE) films from single-use supermarket plastic bags to microplastics under laboratory-simulated onshore and nearshore conditions was investigated for a period of 6 months. The weathering process of the plastic strips either on beach sand or in seawater under direct natural sunlight was monitored by tensile strength, molecular weight measurements, FTIR, weight loss, and image processing of photographs of the plastic strips before and after mild mechanical stress was applied. The latter represents a novel method proposed for determining the onset of fragmentation through the application of mild mechanical stress on the weathered plastic samples emulating the action of sand and wind on a beach. It was found that 12 h of application of mild mechanical stress in rotating glass bottles filled partially with sand was sufficient time to reach the maximum degree of fragmentation that could occur for the weathered plastics samples being tested. For example, applied mechanical stress yielded an area loss of almost 14% for samples weathered for a period of 5 months and about 16.7% after 5.5 months. While tensile strength tests and molecular weight measurements were rather inconclusive till the very last month when the onset of fragmentation was identified; FTIR measurements revealed that samples under ultraviolet irradiation were gradually modified chemically until fragmentation commenced. After 6 months of weathering, molecular weight measurements showed a 60% reduction for sample SMB-1 whereas for sample SMB-2 the measurement was not possible due to extensive fragmentation. The onset of fragmentation for SMB-1 and SMB-2 samples occurred at a cumulative luminance of 5.3 × 10 6 lux•d and in the presence of atmospheric oxygen whereby the polymer films broke down partially to microplastics. When the UV exposure reached 7.2 × 10 6 lux•d the weathered plastic strips broke down fully to microplastics with the application of a mild mechanical stress. Samples placed in seawater proved to be resistant to fragmentation compared to those on sand over the 6-month period of the weathering experiment. The direct implication of this work is that beached macroplastic debris should be regularly collected from the seashore before they are weathered by sunlight and returned to the sea as microplastics by the action of high waves or strong winds.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Microplastics Generation: Onset of Fragmentation of Polyethylene Films in Marine Environment Mesocosms

et al. 2017

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“…Both factors conduce to changes in morphology and crystallinity (Sen and Raut 2015), and consequently alter macromolecular properties of plastics. While the ambient temperature in the Colombian Caribbean coast can reach 39 ºC during the day and 25 ºC at night, in river and sea values are more stable.…”

Section: Discussionmentioning

confidence: 99%

Degradation of Conventional and Oxodegradable High Density Polyethylene in Tropical Aqueous and Outdoor Environments

Villamizar

Vázquez‐Morillas

2018

Rev. Int. Contam. Ambie.

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Polyethylene is widely used in packaging due to its chemical stability, lightness, impermeability and low cost. However, these properties become questionable when it is discarded. Oxodegradable plastics, which degrade by an abiotic-biotic process, have been promoted as a solution to the pollution caused by plastics. This research assesses the degradability of conventional and oxodegradable high density polyethylene in marine, freshwater, and outdoor tropical environments. Samples of these plastics, with and without previous abiotic degradation, were exposed to direct weathering in the Caribbean Sea and the Magdalena River, in Colombia. Their degradation was evaluated during six months by the formation of carbonyl groups, a decrease in elongation at break and visual evidence of deterioration. We found faster degradation for outdoor, followed by marine and freshwater conditions, evidencing that UV and temperature are the most relevant promoters of degradation, especially for oxodegradable plastics, as evidenced by the increase in carbonyl index. In aqueous environments, all specimens showed the formation of biofilm and in some cases cracks and fragmentation, especially in oxidized oxodegradable high density polyethylene specimens in the marine environment. Even if oxodegradables plastics, and in a lesser degree conventional ones, began their degradation process, they did not achieve complete disintegration or mineralization, due to lack of environmental conditions that can only be guaranteed in carefully monitored waste management systems.Palabras clave: contaminación por plásticos, microplásticos, ambientes acuáticos, fotooxidación RESUMENEl polietileno se utiliza ampliamente en el envasado debido a su estabilidad química, ligereza, impermeabilidad y bajo costo. Sin embargo, estas propiedades son cuestionables cuando se desecha. Los plásticos oxodegradables, que se degradan por un proceso abiótico-biótico, se han promovido como solución. Esta investigación evalúa la capacidad de descomposición del polietileno convencional de alta densidad y el oxodegradable en ambientes tropicales marinos, de agua dulce y a la intemperie. Las C.A. Arias-Villamizar and A. Vázquez-Morillas 138 muestras de polietileno convencional y oxodegradable, con y sin degradación abiótica previa, se expusieron en directo a la intemperie, en el mar Caribe y en el río Magdalena, en Colombia. Se evaluó su degradación durante seis meses por la formación de grupos carbonilo, la disminución del porcentaje de elongación a la ruptura y mediante evidencias visuales de deterioro. Se encontró degradación más rápida para las condiciones al aire libre, lo que demuestra que la radiación UV y el perfil de temperatura son los promotores más pertinentes de la degradación, especialmente en plásticos oxodegradables, como se evidencia por el aumento en el índice de carbonilo. En sistemas acuosos, todas las probetas exhibieron biopelícula, en algunos casos se encontraron grietas y se observó fragmentación. Especialmente se encontró este comportamiento en l...

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“…Biodegradation is the tendency of a polymer to get break down into its components by microorganisms. 17 bacterial and 9 fungal genera are known which are capable of degrading polyethylene (Sen and Raut 2015;Restrepo-Flórez et al 2014). Degradation of polyethylene with fungi is preferred over bacteria because of their high production potential and good penetrating ability (Hanaa et al 1998).…”

Section: Introductionmentioning

confidence: 99%

Biodegradation of thermally treated low density polyethylene by fungus Rhizopus oryzae NS 5

et al. 2017

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Polythene is considered as one of the important object used in daily life. Being versatile in nature and resistant to microbial attack, they effectively cause environmental pollution. In the present study, biodegradation of low-density polyethylene (LDPE) have been performed using fungal lab isolate Rhizopus oryzae NS5. Lab isolate fungal strain capable of adhering to LDPE surface was used for the biodegradation of LDPE. This strain was identified as Rhizopus oryzae NS5 (Accession No. KT160362). Fungal growth was observed on the surface of the polyethylene when cultured in potato dextrose broth at 30°C and 120 rpm, for 1 month. LDPE film was characterized before and after incubation by Fourier transform infrared spectroscopy, scanning electron microscopy, atomic force microscopy and universal tensile machine. About 8.4 ± 3% decrease (gravimetrically) in weight and 60% reduction in tensile strength of polyethylene was observed. Scanning electron microscope analysis showed hyphal penetration and degradation on the surface of polyethylene. Atomic force microscope analysis showed increased surface roughness after treatment with fungal isolate. A thick network of fungal hyphae forming a biofilm was also observed on the surface of the polyethylene pieces. Present study shows the potential of Rhizopus oryzae NS5 in polyethylene degradation in eco friendly and sustainable manner.

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Microbial degradation of low density polyethylene (LDPE): A review

Cited by 311 publications

References 105 publications

Microplastics Generation: Onset of Fragmentation of Polyethylene Films in Marine Environment Mesocosms

Microplastics Generation: Onset of Fragmentation of Polyethylene Films in Marine Environment Mesocosms

Degradation of Conventional and Oxodegradable High Density Polyethylene in Tropical Aqueous and Outdoor Environments

Biodegradation of thermally treated low density polyethylene by fungus Rhizopus oryzae NS 5

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