Polyethylene Strips Research Articles

Optimisation of Some Conditions for the Biodegradation of Low-Density Polyethylene Strips by Fungi Isolated from Parts of North Central Nigeria

Optimisation of Some Conditions for the Biodegradation of Low-Density Polyethylene Strips by Fungi Isolated from Parts of North Central Nigeria

Searching for bacterial plastitrophs in modified Winogradsky columns

IntroductionPlastic pollution has surged due to increased human consumption and disposal of plastic products. Microbial communities capable of utilizing plastic as a carbon source may play a crucial role in degrading and consuming environmental plastic. In this study, we investigated the potential of a modified Winogradsky column (WC) to enrich Connecticut landfill soil for plastic-degrading bacteria and genes.MethodsBy filling WCs with landfill soil and inorganic Bushnell Haas medium, and incorporating polyethylene (PE) strips at different soil layers, we aimed to identify bacterial taxa capable of degrading PE. We employed high-throughput 16S rRNA sequencing to identify the microbes cultivated on the plastic strips and the intervening landfill soil. We used PICRUSt2 to estimate the functional attributes of each community from 16S rRNA sequences.Results and discussionAfter 12 months of incubation, distinct colors were observed along the WC layers, indicating successful cultivation. Sequencing revealed significant differences in bacterial communities between the plastic strips and the intervening landfill-soil habitats, including increased abundance of the phyla Verrucomicrobiota and Pseudomonadota (néé Proteobacteria) on the strips. Based on inferred genomic content, the most highly abundant proteins in PE strip communities tended to be associated with plastic degradation pathways. Phylogenetic analysis of 16S rRNA sequences showed novel unclassified phyla and genera enriched on the plastic strips. Our findings suggest PE-supplemented Winogradsky columns can enrich for plastic-degrading microbes, offering insights into bioremediation strategies.

Optimum conditions for the biodegradation of waste low-density polyethylene strips by bacteria isolated from parts of north central Nigeria

Optimum conditions (Temperature, pH and incubation time) were studied for selected bacterial isolates Pseudomonas aeruginosa1(PA1), Pseudomonas aeruginosa2 (PA2), Bacillus megaterium, Providencia stuarti, Alcaligenes faecalis, Enterobacter hormaechei, Klebsiella pneumonia and Proteus vulgaris to biodegrade low-density polyethylene (LDPE) waste by using Basal Salts Medium (BSM) containing 0.500g LDPE strips (1 cm by 5 cm each) using changes in mechanical properties and weight loss of the strips as indicators for ability of these microorganisms to degrade LDPE. The results revealed that four of the eight bacterial isolates, Pseudomonas aeruginosa1, Pseudomonas aeruginosa2, Bacillus megaterium, and Providencia stuarti showed high ability to degrade the LDPE strips after 8 weeks of incubation in liquid Basal Salts Medium at pH 6.5 -7.5 and 32oC. The tensile strength of the LDPE strips was reduced by 0.047±0.41 MN/M2 (47%) for P. aeruginosa1, 0.040±0.30 MN/M2 (40%) for P. aeruginosa2, Bacillus megaterium, 0.033±0.61 MN/M2 (33%), and Providencia stuarti, 0.027±0.41 MN/M2 (27%). The weight loss of the LDPE recorded for Pseudomonas aeruginosa1 was 19.80±0.04 %, for Pseudomonas aeruginosa2 19.40±0.08 %, 13.40±0.10 %, for Bacillus megaterium and 19.20±0.42 % for Providencia stuarti respectively. There was significant difference in the weight loss of the LDPE strips at pH 6.5 for Bacillus megaterium, Providencia stuarti, Alcaligenes faecalis and Enterobacter hormaechei and at 30-32 oC for Pseudomonas spp., Bacillus megaterium, Klebsiella pneumonia and Proteus vulgaris(P>0.05 %).

Fibre reinforcement of railway ballast to reduce track settlement

Most of the world's railways run on ballasted track. However, ballast accumulates differential settlement with trafficking, hence the correct track level must be restored periodically – typically by tamping, which is costly. To reduce the cost of maintenance, several interventions have been proposed with the objective of increasing the interval between tamps by reducing the rate of differential settlement. These include broader ballast gradings, geogrids and under-sleeper pads. A possible alternative is the addition of unbound random fibres to the ballast. Fibres formed from polymer materials, randomly mixed with sands and gravels, have been shown to increase their shear resistance owing to the additional effective confinement associated with the mobilisation of tension in the fibres. However, the effect of the fibres on the permanent strain accumulated under cyclic loading has not been extensively investigated. This paper presents the results of an experimental programme carried out to assess the performance of full-size ballast reinforced with different proportions of polyethylene strip fibres of different lengths and widths. It shows that the addition of a moderate amount (0·6–0·7% of the volume of solids) of narrow fibres has negligible influence on grain packing and can reduce ballast plastic settlement without affecting track resilient stiffness.

Best application of low-cost enhancement treatment for agricultural drain wastewater

This study aimed to apply a new technique of treatment inside stream using polyethylene sheets strips as a very cheap method for enhancing the quality of agriculture wastewater to meet the irrigation reuse needs. The study was carried out on a pilot plant that was constructed by EU research project named “drains water quality enhancement” inside Faqous Wastewater Treatment plant nearby Bahr El Bakar agricultural drain in El Sharqiyah Governorate, Egypt. Polyethylene strips were used as in stream media treatment where the operation program was made to determine the best positioning for applied serial lines to achieve the target water quality for reuse purposes, The study used four intervals first was 30 cm in channel 2 ,the second was 70cm in channel 3, the third was 100cm in channel 4 ,and the fourth was 150 cm in channel 5 to get the best enhancing efficiency and the removal ratios for Biochemical Oxygen demand (BOD), Chemical Oxygen demand( COD) & Heavy metals (HM). Each channel contains six serial curtain lines to determine the study parameters. The results showed that the first interval 30 cm achieved removal ratios 44.6 %for BOD, 27 %for COD, and 41.7% for HM, while interval 70 cm produced removal ratios 46 %for BOD, 27.7 %for COD, and 43.3% for HM, for the third interval 100 cm the study get the removal ratios 51.6 %for BOD, 30 %for COD, and 46 % for HM, and finally for interval 150 cm the resulted removal ratio were 52.6 %for BOD, 30.5 %for COD, and 48 % for HM. The study proved that the curtain lines interval should be equal to or more than double the water depth in the stream to achieve higher removal efficiency in all measured parameters.

Textile dyeing wastewater treatment by Penicillium chrysogenum: Design of a sustainable process.

In this work a parametric study and a bench bioreactor degradation test of Direct Black 22 (DB22) by Penicillium chrysogenum was performed as a first approach to an industrial application, framed within a policy of sustainable processes development. Three ancillary carbon sources and their optimum initial concentrations were studied. These were: glucose, potato starch and potato industry wastewater. Their optimum initial concentration was 6 g/L. The use of potato starch as co-substrate showed the highest decolorization rate and COD removal. Degradation of DB22 using different immobilization supports (stainless steel sponge, loofah sponge and polyethylene strips) was studied and the results showed that the time needed for the treatment decreased from 6 to 4 d. Phytotoxicity was evaluated in the final products of the immobilized cells assays, using Lactuca sativa seeds. For all treatments phytoxicity was reduced with respect to the untreated wastewater, except for the assays using polyethylene strips. Finally, the reuse of the biomass attached to different carriers and the performance of the treatment of DB22 in a 1 L bench scale bioreactor were tested. P. chrysogenum decolorized at least four sucesives reuses. The reactor assays showed a better performance of the treatment.

Biodegradation of polyethylene by indigenous fungi from waste recycling site, South West, Nigeria

BackgroundIndiscriminate disposal of polyethylene materials has become a regular practice among developing nations of Africa, especially in Nigeria. This has resulted in environmental pollution; hence, this study investigates the microbial degradation of polyethylene obtained from a polyethylene dumpsite in South West, Nigeria, under static in vitro condition. Soil samples were analysed for mineral composition and physicochemical characteristics. The fungal isolates were screened for polyethylene degradation using minimal salt medium containing polyethylene as sole source of carbon and nitrogen for their ability to degrade polyethylene. Gravimetric analysis and Fourier-transform infrared spectroscopy (FTIR) were used to monitor the biodegradation of the polyethylene.ResultsAspergillus flavus, A. nidulans, Penicillium chrysogenum, Mucor mucedo, Eurotium repens, A. fumigatus and Rhizopus stolonifer were enumerated. Mean microbial count ranged from 1.37 × 107 to 8.2 × 108 SFU/g. Individual weight loss was observed in the polyethylene strip cultured with P. chrysogenum (1%), E. repens (1%) and A. nidulans (2%). The changes observed in the FTIR spectra especially the polyethylene sample inoculated with A. nidulans confirm the significant role of fungi in polyethylene degradation. Hence, its usage in the treatment of polyethylene in the environment is a cheap eco-friendly alternative.ConclusionAspergillus nidulans, E. repens and P. notatum play significant roles in the biodegradation of polyethylene which necessitates incorporating in polyethylene products waste management to foster a cleaner environment.

BEHAVIOUR OF SILTY SAND REINFORCED WITH LOW DENSITY POLYETHYLENE (LDPE) STRIPS

In this study, silty sand is reinforced with plastic strips to improve the engineering properties of soil. Sand and silty sand soils have been used as base materials and low-density polyethylene (LDPE) strips as reinforcement materials. The LDPE strips are used in various dimensions (e.g., width ranging from 6 to 15mm and length ranging from 15 to 30mm). The randomly distributed LDPE strips are added to sand and silty sand specimens at varying percentages (e.g., 0.1% to 0.3%) by weight of dry soil specimen. Direct shear tests are performed on sand and silty sand specimens in both unreinforced and reinforced conditions. Stress strain, volumetric strain (e.g., compression/dilation behaviour) and strength envelopes are plotted to investigate the improvement in the shear strength parameter (e.g., internal friction angle). The results show that in sand specimens, the maximum improvement in shearing behaviour has been achieved with strips of 6x30mm in dimensions and at 0.3%. For silty sand specimens, the maximum improvement in shearing behaviour has been achieved with strips of 6x25mm in dimensions and at 0.3%. In addition, it has been observed that reinforced soil specimens increased the values of internal frictional angle compared to unreinforced soil specimens. In sand specimens, maximum increase of 19.72% in internal friction angle (Φ) has been observed with 6x30mm strips at similar percentage. In case of silty sand specimens, the maximum increase in internal friction angle (Φ) has been observed as 19.28% with the addition of strips of 6x25mm and at 0.3%.

Examining the dependence of macroplastic fragmentation on coastal processes (Chesapeake Bay, Maryland)

Plastic debris in the coastal environment is subject to complex and poorly characterized weathering processes. To better understand how key environmental factors affect plastic degradation in a coastal zone, we conducted an in situ experiment. We deployed strips of high density polyethylene (HDPE) and polystyrene (PS) in paired coastal areas of contrasting conditions (hydrodynamic activity: erosional or depositional; water depths: subtidal or intertidal). Strips were collected after environmental exposures at 4, 8, and 43 weeks and analyzed for change in mass, algal biofilm growth, and imaged by petrographic and electron microscopy (SEM-EDS). Significant surface erosion was evident on both polymers, and was more rapid and more extensive with PS. Degradation of PS was responsive to intensity of hydrodynamic activity, and was greater at intertidal depths, highlighting the critical role played by photo-oxidation in the coastal zone, and suggesting that algal biofilms may slow degradation by playing a photo-protective role.

Effects of Low-Density Polyethylene (LDPE) Strips on Some Engineering Properties of Cement-Stabilized Lateritic Soils

The study investigated the compaction and strength characteristics of lateritic soils stabilized with 3% cement and waste sachet water-proof (low-density polyethylene, LDPE) strips. Three (3) lateritic samples collected from Ugwuoba, Nawfia, and Okpuno in Enugu and Anambra states of Nigeria were used in the study. Index properties tests on the samples show that they fall within class A-2-6(1) and A-2-4(0) based on the American Association of State Highway and Transportation Officials (AASHTO) and SM/SC based on Unified Soil Classification System (USCS). LDPE strips were varied at 0, 0.25, 0.5, 0.75, 1, 1.5, and 2% based on the dry unit weight of the soil. Results of unconfined compressive strength (UCS) tests show significant improvement in the strength of the soils at 2 % LDPE strips. Statistical analysis also shows that a significant relationship exists between the percentage of LDPE strips, compactive effort, and maximum dry unit weight (MDUW)/optimum moisture content (OMC), UCS of the soils. The tensile and flexural strength of lateritic soil stabilized with 3% cement can be improved optimally by the addition of 2% of low-cost LDPE strips of aspect ratio (AR) of 10 mm  10 mm.

Development of biofilm collectors as passive samplers in sewerage systems-a novel wastewater monitoring method.

In this study, a novel wastewater sampling method based on biofilm collection on a multi-armed polyethylene strips (so called "Octopus") is proposed. The implementation of this method is a step forward to prevent illegal industrial discharges into sewerage systems and receiving water bodies. Prior applications of biofilm collection were performed in Bielefeld, Germany, in 1994. The success of the method encouraged other municipalities to apply this method for monitoring indirect discharges into sewerage systems. Municipality of Konya, Turkey, started to use the method in 2013. Continuous monitoring has been performed for the determination of regulated heavy metals: chromium (Cr), copper (Cu), zinc (Zn), nickel (Ni), lead (Pb), mercury (Hg) and cadmium (Cd). Unauthorized discharges of Cr, Zn and Ni were identified in Konya by performing sewerage slime tests through biofilm analyses. 2686mg/kg d.m. Cr, 3949mg/kg d.m. Zn and 3300mg/kg d.m. Ni were highest values determined for biofilm samples taken from monitoring sites. In this paper, the principles of the method will be introduced, and findings from the wastewater of Konya City will be given in comparison with findings from Bielefeld, Germany. Conducted results reveal high (and likely illegal) heavy metal discharges into the sewerage system in Konya. The continuous monitoring of sewerage systems with biofilm collectors is an effective and efficient method for point source control of wastewater pollutants.

Effect of Polyethylene Strips Surface Roughness on Its Efficiency for Enhancement of Wastewater Treatment

This study aimed to determine the effect of roughness surface for polyethylene strips on its quality for enhancement the characteristics of wastewater treatment plant effluent as a very cheap method. The study was applied at Abu Rawash WWTP effluent channel using the smooth and rough polyethylene strips where a biofilm layer forms above its surface. The removal ratio for smooth polyethylene strips for BOD and TSS was 4.45 and 4.33% respectively, while for the rough polyethylene strips was 14.10 and 13.37 respectively. This shows the success of the polyethylene strips even smooth or rough to remove both the BOD and TSS from treated wastewater. The results show that the material roughness affected the treatment efficiency with proportional effect. And the rough surface has a good removal efficiency that makes it more applicable for such purpose of enhancing the treated wastewater with very low cost technique.

Reduced bioavailability of polycyclic aromatic hydrocarbons (PAHs) in sediments impacted by carbon manufacturing plant effluent: Evaluation by ex situ passive sampling method

Potential risks of polycyclic aromatic hydrocarbons (PAHs) in sediments of a Japanese bay contaminated by carbon manufacturing plant effluent were evaluated by calculating toxicity units (TUs). TUs calculated from the measured whole-sediment concentrations (Cwhole) were often higher than or close to 1, signaling a possible toxicity concern to benthic organisms. In contrast, TUs based on the freely dissolved pore water concentrations (Cfree) measured by an ex-situ passive sampling method with polyethylene strips were 0.0007–0.005, much lower than 1, indicating no effect. We also found that the fractions of black carbon in sediments of the contaminated bay were significantly higher than those of reference sites. Overall, we conclude that carbon manufacturing plant effluent substantially increases Cwhole of PAHs in sediments but also increases the fraction of carbonaceous particles that strongly retain PAHs. As a combined result, bioavailable concentrations (as expressed by pore water Cfree) of PAHs do not increase as much as Cwhole. The results of this study indicate that ecotoxicological risks of PAH contamination by carbon manufacturing plants should be evaluated by directly measuring pore water Cfree instead of Cwhole.

Monitoring of explosive residues in lake-bottom water using Polar Organic Chemical Integrative Sampler (POCIS) and chemcatcher: determination of transfer kinetics through Polyethersulfone (PES) membrane is crucial

Between 1920 and 1967, approximatively 8200 tons of ammunition waste were dumped into some Swiss lakes. This study is part of the extensive historical and technical investigations performed since 1995 by Swiss authorities to provide a risk assessment. It aims to assess whether explosive monitoring by passive sampling is feasible in lake-bottom waters. Polar organic chemical integrative sampler (POCIS) and Chemcatcher were first calibrated in a channel system supplied with continuously refreshed lake water spiked with two nitroamines (HMX and RDX), one nitrate ester (PETN), and six nitroaromatics (including TNT). Exposure parameters were kept as close as possible to the ones expected at the bottom of two affected lakes. Sixteen POCIS and Chemcatcher were simultaneously deployed in the channel system and removed in duplicates at 8 different intervals over 21 days. Sorbents and polyethersulfone (PES) membranes were separately extracted and analyzed by UPLC-MS/MS. When possible, a three-compartment model was used to describe the uptake of compounds from water, over the PES membrane into the sorbent. Uptake of target compounds by sorbents was shown not to approach equilibrium during 21 days. However, nitroaromatics strongly accumulated in PES, thus delaying the transfer of these compounds to sorbents (lag-phase up to 9 days). Whereas sampling rate (RS) of nitroamines were in the range of 0.06–0.14 L day−1, RS of nitroaromatics were up to 10 times lower. As nitroaromatic accumulation in PES was integrative over 21 days, PES was used as receiving phase for these compounds. The samplers were then deployed at lake bottoms. To ensure that exposure conditions were similar between calibration and field experiments, low-density polyethylene strips spiked with performance reference compounds were co-deployed in both experiments and dissipation data were compared. Integrative concentrations of explosives measured in the lakes confirmed results obtained by previous studies based on grab sampling.

Plastic waste management, a matter for the 'community'.

Plastic waste management, a matter for the 'community'.

Using performance reference compounds to compare mass transfer calibration methodologies in passive samplers deployed in the water column.

Performance reference compounds (PRCs) are often added to passive samplers prior to field deployments to provide information about mass transfer kinetics between the sampled environment and the passive sampler. Their popularity has resulted in different methods of varying complexity to estimate mass transfer and better estimate freely dissolved concentrations (Cfree ) of targeted compounds. Three methods for describing a mass transfer model are commonly used: a first-order kinetic method, a nonlinear least squares fitting of sampling rate, and a diffusion method. Low-density polyethylene strips loaded with PRCs and of 4 different thicknesses were used as passive samplers to create an array of PRC results to assess the comparability and reproducibility of each of the methods. Samplers were deployed in the water column at 3 stations in New Bedford Harbor (MA, USA). Collected data allowed Cfree comparisons to be performed in 2 ways: 1) comparison of Cfree derived from one thickness using different methods, and 2) comparison of Cfree derived by the same method using different thicknesses of polyethylene. Overall, the nonlinear least squares and diffusion methods demonstrated the most precise results for all the PCBs measured and generated Cfree values that were often statistically indistinguishable. Relative standard deviations (RSDs) for total PCB measurements using the same thickness and varying model types ranged from 0.04 to 12% and increased with sampler thickness, and RSDs for estimates using the same method and varying thickness ranged from 8 to 18%. Environmental scientists and managers are encouraged to use these methods when estimating Cfree from passive sampling and PRC data. Environ Toxicol Chem 2018;37:2089-2097. Published 2018 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

Turfgrass Cover Sources Vary in Temperature, Light and Moisture Penetration, and Weight

Turfgrass managers apply covers to manipulate grass and soil environments. This study evaluated how various cover compositions and colors affect winter temperatures under cover, light and moisture penetration, and wet and dry weights of covers in the field. Seven covers including interwoven translucent polyethylene, gray, white, or orange nonwoven geotextiles, black and white woven polypropylene, and aluminized high‐density polyethylene strips were tested in Blacksburg, VA. Covers were in place December to March of 2013–2014 and 2014–2015 to evaluate bermudagrass (Cynodon dactylon × transvaalensis Burtt‐Davy, ‘Patriot’) surface temperature moderation. Cover effects on photosynthetically active radiation (PAR), moisture penetration (measured as percent change in soil volumetric water content [%SVWC] at 5‐cm soil depth under cover prior to and following a minimum 1.25 cm rain event), as well as cover dry and wet weights in the field prior to and after 0.1 cm irrigation were collected in spring 2016. Considering mean minimum extreme low temperatures, all covers provided significantly higher temperatures than uncovered control in 2013–2014, while in 2014–2015 all covers except for interwoven translucent polythethylene and aluminized high‐density polyethylene strips exceeded the control. Of standard covers, translucent polyethylene had the highest PAR transmission and was always in the top statistical category for mean maximum and daily range temperatures. Orange geotextile had the greatest dry and wet weights and gray and orange geotextiles had the lowest change in %SVWC on a 3% sloped native soil. Understanding differences in cover parameters will aid turfgrass managers in appropriate cover selection.

Dielectric-technique-assisted breast cancer surgery

Introduction. In conservative breast cancer surgery, removing all carcinogenic lesions is a sound basis for achieving therapeutic success. The cleanness of the cutting margin is usually assessed after surgery and any residual cancerous tissue that are found, require further surgery. A simple and cheap assessment method is presented which can be used during surgery, the dielectric cancer probe (DCP), which allows the surgeon to take fast decisions on whether to extend incisions. Method. The DCP method consists of measuring and then differentiating between the electrical properties (permeability and conductivity) of healthy and cancerous breast tissue. A polyethylene strip is used to separate the examined tissue from the instrument probe and the procedure is carried out by the operating surgeon. Results. This method was found to allow correct identification of cancerous breast tissue based on taking 189 samples from 70 patients using the intraoperative hand probe. The sensitivity and specificity were respectively 87% and 99%. Conclusions. The DCP is a high sensitivity method and is totally safe for the patient and can be used intraoperatively. The device is an aid to the surgeon for differentiating between healthy and cancerous breast tissue. Its widespread use should reduce the number of reoperations in the conservative surgical management of breast cancer patients.

Comparing polyethylene and polyoxymethylene passive samplers for measuring sediment porewater concentrations of polychlorinated biphenyls: Mutual validation and possible correction by polymer-polymer partition experiment

Two sediment passive samplers, polyethylene (PE) and polyoxymethylene (POM), were compared and mutually validated for measuring freely dissolved concentrations (Cfree) of polychlorinated biphenyls (PCBs) in sediment porewater. PE and POM strips in commonly used dimensions (30 and 76 μm in thickness, respectively) were exposed to sediment slurries for 28 d. The Cfree values calculated using literature polymer-water partition coefficients were consistently higher for PE than for POM by a factor of 2 on average. Time series experiments over 96 d show that 28 d are sufficient for attaining partition equilibrium of PCBs for PE, whereas even 96 d may not be enough for POM. To gain additional insight, POM and PE strips were co-exposed to bovine serum albumin suspension spiked with PCBs. The POM/PE concentration ratios increased over 56 d, and the ratios at 28 d were in agreement with the POM-to-PE ratios of PCB concentrations from the 28-d sediment slurry experiments. This agreement suggests that the use of apparent POM-water partition coefficients (i.e., non-equilibrium concentration ratios) suitable for a 28-d exposure to sediment slurries may correct the non-attainment of equilibrium and could provide more accurate Cfree values.

Studies and Research on the Electrical Resistance of the Polyethylene Insulation Used for the Chemical Protection of the Steel Pipelines Intended for the Natural Gas Distribution

The paper aims to find solutions to some of the problems the staff operating the natural gas networks have to face, which are the low, medium and high pressure, and the corrosion of the steel pipelines. This metal corrosion can be dealt with by insulating it through various procedures, the latest being the different thickness polyethylene strips insulation. The goal of the paper is to observe the insulation areas on the pipeline which can be destroyed by mechanical factors during operation and the method of remedying these faults with high density polyethylene strips.