Degradation Of Low Density Polyethylene Films Research Articles

Biodegradation of low-density polyethylene film by Bacillus gaemokensis strain SSR01 isolated from the guts of earthworm.

In recent years, low-density polyethylene (LDPE) has emerged as an essential component of the routine tasks that people engage in on a daily basis. However, over use of it resulted in environmental buildup that contaminated aquatic habitats and human health. Biodegradation is the most effective way for controlling pollution caused by synthetic plastic waste in a sustainable manner. In the present study, the LDPE degrading bacterial strain was screened from gut of Earthworms collected from plastic waste dumped area Mettur dam, Salem district, Tamil Nadu, India. The LDPE degrading bacterial strain was screened and identified genotypically. The LDPE degrading Bacillus gaemokensis strain SSR01 was submitted in NCBI. The B. gaemokensis strain SSR01 bacterial isolate degraded LDPE film after 14days of incubation and demonstrated maximum weight loss of up to 4.98%. The study of deteriorated film using attenuated total reflection-Fourier transform infrared revealed the presence of a degraded product. The degradation of LDPE film by B. gaemokensis strain SSR01 was characterized by field-emission scanning electron microscopy analysis for surface alterations. The energy dispersive X-ray spectroscopy test confirmed that the broken-down LDPE film had basic carbon reduction. The present study of LDPE flim biodegradation by B. gaemokensis strain SSR01 has acted as a suitable candidate and will help in decreasing plastic waste.

Biodegradation of LDPE (low density polyethylene) using bacterial strain

The applications of polyethylene are enormous and they are popular because of their relatively low cost, lack of difficulty in manufacture, adaptability and durability. In the past decade, the increase in the utilization of plastics and the accumulation of polyethylene in the environment all around the globe has drawn the attention of environmentalists and scientists. The plastic materials are commonly derived from petrochemicals extracted from coal and natural gas. They are produced in a wide range in synthetic, semi synthetic organic polymers. The degradation of LDPE film was determined by residual dry weight loss of the LDPE films. The potent strain showed 42.5% degradation ability in 90 d. Degradation of LDPE results in the breakdown of the polymer backbone chain producing CO2 which was checked by gravimetric analysis. Enzyme kinetic studies showed the production of three ligninolytic extracellular enzymes- lignin, laccase and manganese peroxidase by bacterial strain AJ01 in LDPE degradation. Degradation of LDPE strips followed first order kinetics model with a rate constant (R2) of 0.9783 d-1. Estimation of protein from post treated LDPE using bacterial isolate showed a total concentration of 0.440mg/0.1mL and 0.703mg/0.2mL. LDPE degradation was confirmed by using analytical techniques such as SEM which showed changes in the surface topology of LDPE strips and FTIR analysis showed changes in complex chemical structure of LDPE post 90 d of degradation using microorganisms thereby reducing carbonyl index (CI) value.

Green synthesized Pd-Ni nanohybrids for controlled degradation of low-density polyethylene films

This study reports the potential application of Pd-Ni bimetallic nanoparticles as a photo-catalyst for the degradation of low-density polyethylene films. Ananas comosus extract was used in the biosynthesis of Pd-Ni bimetallic nanoparticles. The extract’s phytochemical compounds served as reducing and stabilizing agents, facilitating the bioreduction process. The as-synthesized Pd-Ni bimetallic nanoparticles were incorporated into LDPE films with or without solar radiation. The reaction kinetics was used to observe the polyethylene films’ pattern of degradation. Photo-induced weight loss, FTIR, SEM, and TGA analyses were used to characterize the pure LDPE and nanocomposite films. After 210 h of solar irradiation, the weight loss of solar-treated Pd-Ni nanocomposite films and pure LDPE lost 40.04 ± 2.3% and 8.60 ± 0.5%, respectively. While the untreated Pd-Ni nanocomposite (dark) showed a weight loss of 1.79 ± 0.39%. The FTIR and SEM analyses confirmed the new peaks, carbonyl group generation, and formation of cavities on the polymer matrix of solar-treated Pd-Ni nanocomposite. However, this study suggests the use of Pd-Ni bimetallic nanoparticles as a photo-catalyst to enhance the photocatalytic degradation of low-density polyethylene, which could be useful in the polymer industry to combat environmental pollution.

In situ degradation of low-density polyethylene film in irrigation maize field: Thickness-dependent effect

Thickness of low-density polyethylene (LDPE) film might determine its mechanical strength, clean production and soil health. Yet, this issue is little understood. In situ aging effects were evaluated in LDPE films with the thickness of 0.006 mm, 0.008 mm, 0.010 mm and 0.015 mm in maize field. The data showed that maximum tensile force (TFmax), maximum tensile strength (TSmax) and elongation at break (EAB) were massively lowered with increasing thickness after aging. The greatest and lowest reduction magnitude of EAB was 27.6 % and 11.2 % in 0.006 mm and 0.015 mm films respectively. Also, the melting point (Tm) and crystallinity (Xc) under Differential Scanning Calorimeter (DSC) tended to decline with the increasing thickness. Moreover, the peak intensity of crystalline regions tended to transfer and concentrate on the amorphous regions, and such tendency became more pronounced in the thin films. Interestingly, there existed a pronounced distinct thickness-dependent effects on soil bulk density (SBD) and soil water-stable aggregate proportion. Thick plastic film mulching increased SBD but reduced the proportion of macroaggregates (mainly referred to 0.015 mm and 0.010 mm). In addition, thick film mulching slightly reduced the levels of soil organic carbon (SOC) and total nitrogen (TN), but significantly promoted the contents of soil labile C and N. Particularly, it significantly promoted above- & under-ground biomass of maize across two growing seasons (p < 0.05). To sum up, thickening LDPE film may act as a promising solution to improve LDPE film residue recycling, while benefiting for higher productivity. However, thick film mulching may cause a certain adverse impact on soil structure, and further investigations would be needed in the future.

Marine bacterial based enzymatic degradation of low-density polyethylene (LDPE) plastic

Polyethylene has become an essential part of the day-to-day activities of human life. However, its excess use led to accumulation in the environment-causing marine pollution without having any safe and proper disposable methods. Biodegradation is the most efficient method to control synthetic plastic waste pollution sustainably. In the present study, we used three identified marine bacterial isolates (two Marinobacter sp. (H-244 and H-246) and one Bacillus subtilis (H-248)) to degrade unplasticized low-density polyethylene film after screening and showed maximum weight loss up to 1.68% by H-246 bacterial isolate within 90 days. The degradation of LDPE film by bacteria was characterized by field-emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM) analysis for topographical changes such as crack, pits, cavity and roughness. The attenuated total reflection-Fourier transform infrared (ATR-FTIR) analysis of degraded film showed the addition of extra-functional group at the range of 1025–1275 cm−1 with an increase in C-O stretching that is due to the addition of alcohol (–OH) group, which was further confirmed by the gas chromatography-mass spectrometry (GC-MS) analysis of degraded by-products release of fatty acids due to esterase activity. A decrease in tensile strength (0.43 MPa) and thermal weight loss (99.63%) in LDPE degraded by bacterial isolate H-246. Carbon content was also reduced in the bacterial degraded LDPE film from 86.10% to 80.45% for bacterial isolate H-244. All these characteristic changes in polyethylene were occurred due to esterase enzyme production by the bacteria and confirmed by isolation and purification, which showed 32, 32 and 43 KD of molecular weight for bacterial isolate H-244, H-246 and H-248, respectively. The present study of LDPE biodegradation by three marine bacteria has acted as a suitable candidate and will help in decreasing plastic waste.

Low-Density Polyethylene Film Biodegradation Potential by Fungal Species from Thailand.

Accumulated plastic waste in the environment is a serious problem that poses an ecological threat. Plastic waste has been reduced by initiating and applying different alternative methods from several perspectives, including fungal treatment. Biodegradation of 30 fungi from Thailand were screened in mineral salt medium agar containing low-density polyethylene (LDPE) films. Diaporthe italiana, Thyrostroma jaczewskii, Collectotrichum fructicola, and Stagonosporopsis citrulli were found to grow significantly by culturing with LDPE film as the only sole carbon source compared to those obtained from Aspergillus niger. These fungi were further cultured in mineral salt medium broth containing LDPE film as the sole carbon source for 90 days. The biodegradation ability of these fungi was evaluated from the amount of CO2 and enzyme production. Different amounts of CO2 were released from D. italiana, T. jaczewskii, C. fructicola, S. citrulli, and A. niger culturing with LDPE film, ranging from 0.45 to 1.45, 0.36 to 1.22, 0.45 to 1.45, 0.33 to 1.26, and 0.37 to 1.27 g/L, respectively. These fungi were able to secrete a large amount of laccase enzyme compared to manganese peroxidase, and lignin peroxidase enzymes detected under the same conditions. The degradation of LDPE films by culturing with these fungi was further determined. LDPE films cultured with D. italiana, T. jaczewskii, C. fructicola, S. citrulli, and A. niger showed weight loss of 43.90%, 46.34%, 48.78%, 45.12%, and 28.78%, respectively. The tensile strength of LDPE films cultured with D. italiana, T. jaczewskii, C. fructicola, S. citrulli, and A. niger also reduced significantly by 1.56, 1.78, 0.43, 1.86, and 3.34 MPa, respectively. The results from Fourier transform infrared spectroscopy (FTIR) reveal an increasing carbonyl index in LDPE films culturing with these fungi, especially C. fructicola. Analysis of LDPE films using scanning electron microscopy (SEM) confirmed the biodegradation by the presence of morphological changes such as cracks, scions, and holes on the surface of the film. The volatile organic compounds (VOCs) emitted from LDPE films cultured with these fungi were analyzed by gas chromatography-mass spectrometry (GC-MS). VOCs such as 1,3-dimethoxy-benzene, 1,3-dimethoxy-5-(1-methylethyl)-benzene, and 1,1-dimethoxy-decane were detected among these fungi. Overall, these fungi have the ability to break down and consume the LDPE film. The fungus C. fructicola is a promising resource for the biodegradation of LDPE which may be further applied in plastic degradation systems based on fungi.

Degradation of Low-Density Polyethylene Film Exposed to UV Radiation in Four Environments

AbstractLow-density polyethylene (LDPE) when exposed to ultraviolet (UV) radiation under different environmental conditions deteriorates to different extents. The objective of this study was to eva...

Microbial degradation of low density polyethylene

Low‐density polyethylene (LDPE) is potential source of environmental pollution. In this study, biodegradation of LDPE was achieved by employing fungus and actinobacteria isolated from waste dumping site. Among all the isolates, two potential strains were obtained through enrichment technique. Based on 18S rRNA and 16S rRNA analyses the isolated strains were identified as Aspergillus nomius and Streptomyces sp., respectively. The biodegradation of LDPE was determined by evaluating weight loss and morphological changes of the LDPE samples. The isolated strains; Aspergillus nomius had the capacity to degrade 4.9% and Streptomyces sp. showed 5.2% of weight loss of LDPE films respectively. Weight loss of LDPE film after inoculation of isolates in degradation medium indicated that it was capable of using polyethylene as carbon and energy source. CO2 evolution was checked after degradation of polyethylene pieces, the level of CO2 reached 2.85 g L−1 in the presence of Aspergillus nomius and Streptomyces sp. produced 4.27 g L−1. Sophisticated instrumentation was used like atomic force microscopy, Fourier transform infra‐red spectroscopy (FTIR). The breakdown products of the LDPE film after exposure to the isolates was recorded employing GCMS. FTIR spectrum of LDPE film confirmed changes in the presence of chemical groups like amine, alkanes, phenols, and alcohol after degradation of LDPE films by Aspergillus nomius and Streptomyces sp. and the most prominent structural changes of the spectrum were observed in the LDPE sample after 90 days of degradation. The results affirmed the isolates were capable of degrading LPDE films efficiently. © 2016 American Institute of Chemical Engineers Environ Prog, 36: 147–154, 2017

Effect of colorant, thickness, and pro-oxidant loading on degradation of low-density polyethylene films during thermal aging

This work investigated the effect of colorant, thickness and pro-oxidant loading on degradation behavior of low-density polyethylene films during thermal aging. Films were formulated according to Taguchi design of experiments. The following degradation responses were monitored with thermal aging time: tensile strength, oxygen uptake, and carbonyl index. This study showed that colorant and pro-oxidant loading exhibited significant effect on the tensile strength of thermally aged films. White colorant and increased loading of pro-oxidant from 2% to 4% w/w reduced the tensile strength of aged films by 15.9% and 16.9%, respectively. However, incorporating yellow colorant improved the tensile strength of aged films by 3.2% as compared to noncolored films. Meanwhile, all three factors significantly influenced the maximum oxygen uptake of exposed films. White and yellow colorants increased the maximum oxygen uptake of aged films by 90.6% and 56.2%, respectively, when compared to films without colorant. On the other hand, increased film thickness from 1 to 3 mil lowered the maximum oxygen uptake by 31.6%, while increased pro-oxidant loading from 2% to 4% w/w showed an uptake increase of aged films by 204.3%. For the carbonyl index response, the index significantly increased by 84.6% with increased loading of pro-oxidant from 2% to 4% w/w, showing accelerated degradation of exposed films during thermal aging. Enhanced degradation of white films is due to the oxidative reactivity of titanium dioxide present in white colorant. Aromatic amine stabilizer in yellow colorant acts as antioxidant that delays film degradation.

Studies on biodegradation of LDPE film in the presence of potential bacterial consortia enriched soil

Low density polyethylene (LDPE) is an important commodity plastic and has a wide applicability in the modern era. In virtue of their wide applicability, the generation of the huge plastic waste became a conundrum for environment and public health. Consequently, the present study was conducted for the microbial degradation of LDPE film in natural conditions using mixture of potential polymer degrading consortia. For this purpose, the talc based formulation of bacterial consortia was inoculated into soil with LDPE film for the period of three months. Fourier transform infrared spectroscopy (FT–IR) in combination with SEM revealed that the consortia incurred significant surfacial degradation of LDPE film, introduction of hydroxyl (–OH) functionality and significant shifts in fingerprint region, respectively. The potential of the consortia towards degradation of LDPE has further been ascertained through change in bulk structural characteristics using differential scanning calorimetry (DSC). Moreover, the comparative in situ biodegradation study of LDPE film in laboratory and natural conditions indicates that environmental factors like sun-light, temperature and rainfall may enhance the rate of biodegradation of the polymer in nature.

Mechanical, Chemical and Morphological Investigations on the Degradation of Low-Density Polyethylene Films Under Soil-Burial Conditions

Commercial formulations of low-density polyethylene (LDPE) films were subjected to an outdoor soil burial test to investigate the environmental degradation under natural conditions. Samples periodically retrieved from soil were examined for changes in physical character, tensile properties, dielectric behavior, X-ray diffraction pattern and FTIR spectra. Irrespective of thickness and color, load-extension curves of all samples reflect complete or partial destruction of plastic and elastic regions after 15 to 17 months of soil exposure. IR spectra after 17 months revealed major absorption of the region from 1400–1800 cm−1, characteristic of carbonyl peak in polyethylene. Upon exposure, the power factor increased remarkably and fairly intense transition peaks were found in dielectric loss curves. XRD graphs reflected possible damage in the amorphous region of the polymer matrix. Disrupted holes under scanning electron microscope further revealed degradation of LDPE films under natural soil conditions.

Comparative effects of cobalt carboxylates on the thermo‐oxidative degradation of LDPE films

AbstractThis article reports the effect of three cobalt carboxylates—cobalt stearate (CoSt3), cobalt palmitate (CoPal3), and cobalt laurate (CoLau3)—on the thermo‐oxidative degradation of low‐density polyethylene (LDPE) films prepared by sheeting process. The carboxylates were blended with LDPE in the concentration range of 0.05–0.2% (w/w). The degradation was monitored by techniques such as FTIR spectroscopy, change in the mechanical properties (tensile strength and elongation at break), viscometry, surface electron microscopy, melt flow index measurements, and apparent density measurements. Studies indicate that films containing these additives are highly susceptible to thermo‐oxidative degradation. Oxygen containing functionalities such as carbonyl and vinyl species are generated on the surface of polyethylene because of thermo‐oxidation, as indicated by FTIR studies. This oxidative process is accelerated in the presence of cobalt carboxylates. The degradation of LDPE was found to increase proportionally with concentration as well as with increasing chain length of the cobalt carboxylate, and follow the order CoSt3 &gt; CoPal3 &gt; CoLau3. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3758–3765, 2007