scholarly journals Isolation, characterization and optimization of bacterial isolate SARR1 for biodegradation of pretreated low density polyethylene

2021 ◽  
Vol 13 (2) ◽  
pp. 561-570
Author(s):  
Ritu Rani ◽  
Jitender ◽  
Nater Pal Singh ◽  
Anita Rani Santal

Accumulation of low-density polyethylene (LDPE) has caused a threat to the environment because of its stable and inert nature as it cannot be degraded easily by microorganisms. Its lightweight, low cost, strength, durability, and its various other applications, have led to the wide usage of the polymer, which is exerting a negative effect on both marine and land biota. The development of an eco-friendly or a promising strategy is needed to reduce LDPE waste from both land and water. In the present study, observations have been made to isolate highly efficient LDPE degrading bacteria. The response surface methodology (RSM) was used to predict the best optimization of media for the degradation of LDPE by isolate SARR1. The isolate SARR1 was selected through primary screening by weight loss method and secondary screening using CO2 evolution test, TTC and MATH Test. The isolate SARR1 showed 6.30 ± 0.25 g/L CO2 evolution. The microbial adhesion hydrophobicity (MATH) was observed during log phase (100 to 56.89 ± 0.97 %) and stationary phase (100 to 82.92 ± 1.24 %). An isolate SARR1 converted the TTC into red coloured insoluble triphenyl formazan (TPF) after incubation of 7 days. The isolated bacteria SARR1 showed 38.3 ± 1.27 % biodegradation efficiency in the pretreated LDPE strips at 37 °C and pH 7.0 under optimized conditions within 30 days of incubation. This bioremediation and biodegradation approach is eco-friendly and safe for the environment. The results of treatment with isolate SARR1 had a potential hope to degrade LDPE at higher rate than natural degradation.  

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2436
Author(s):  
Abubakar Sadiq Mohammed ◽  
Martina Meincken

Low-cost wood–plastic composites (WPCs) were developed from invasive trees and recycled low-density polyethylene. The aim was to produce affordable building materials for low-cost social housing in South Africa. Both raw materials are regarded as waste materials, and the subsequent product development adds value to the resources, while simultaneously reducing the waste stream. The production costs were minimised by utilising the entire biomass of Acacia saligna salvaged from clearing operations without any prior processing, and low-grade recycled low-density polyethylene to make WPCs without any additives. Different biomass/plastic ratios, particle sizes, and press settings were evaluated to determine the optimum processing parameters to obtain WPCs with adequate properties. The water absorption, dimensional stability, modulus of rupture, modulus of elasticity, tensile strength, and tensile moduli were improved at longer press times and higher temperatures for all blending ratios. This has been attributed to the crystallisation of the lignocellulose and thermally induced cross-linking in the polyethylene. An increased biomass ratio and particle size were positively correlated with water absorption and thickness swelling and inversely related with MOR, tensile strength, and density due to an incomplete encapsulation of the biomass by the plastic matrix. This study demonstrates the feasibility of utilising low-grade recycled polyethylene and the whole-tree biomass of A. saligna, without the need for pre-processing and the addition of expensive modifiers, to produce WPCs with properties that satisfy the minimum requirements for interior cladding or ceiling material.


2019 ◽  
Vol 8 (3) ◽  
pp. 76-82
Author(s):  
K. Zerhouni ◽  
B. Abbouni ◽  
K. Kanoun ◽  
K. Larbi Daouadji ◽  
A. Tifrit ◽  
...  

Plas c bags (Low Density Polyethylene (LDPE) belong to the polymers, which plays a very important role in our daily lives by their diversi ed applica on. However, the accumula on of the plas c bags in the environment cons - tutes a serious problem and a real source for visual nuisance, pollu on of soil and marine environments. Furthermore, their biodegradation was the safest method of breakdown that possibly leaves behind less toxic residues and showed poten al of bio-geo chemical cycling of the substrate. The aim of the present work was the characterization of the isolated bacterial strains from a municipal land ll area of Tlemcen, North West Algeria, which were implicated by the biodegrada on ability of the Low Density Polyethylene. The degradation of the Low Density Polyethylene was inves gated by studying the bacterial growth of the isolated, inoculated on a solid culture medium, which was composed of LDPE as the sole carbon source with and with- out a nitrogen source and the selec on was based by the determination of the produced diameter of hydrolysis clear zone on the surface. Furthermore, the isolated, selected degrading Low Density Polyethylene bacterial ML002 has been iden ed by the study of their morphological, biochemical charac- teris cs and the ampli ca on of the fragment, coding the region of ARN 16S. The use of the API system indicated their belonging to the genus Bacillus Cereus, which has reduced the weight of LDPE by 0.26, 1.28, 1.53% a er 30, 90, 120 days respec vely. Furthermore, the amplified of the fragment, coding the region of ARN 16S by the isolated, selected bacterial ML002 indicated a similarity of 99.394% with Bacillus wiedmannii and Bacillus proteolyticus and 99.293% homology with Bacillus toyonensis, Bacillus cereus and Bacillus thuringiensis.


2019 ◽  
Vol 35 (1) ◽  
pp. 200-206
Author(s):  
Mashael Alshabanat

This work aims to develop green linear low-density polyethylene (LLDPE) composites that are commercially viable due to the low cost of the date palm leaflet filler, which is a local renewable resource. The filler was naturally treated with gum arabic solution. FT-IR, XRD, and SEM techniques were used to characterize the samples. The thermal and mechanical properties were measured by TGA, DSC, and tensile testing. The results showed noticeable changes in the properties of the composites compared to those of the original LLDPE sample. TGA revealed that the composite started thermally. The composites started thermally degrading before the original polymer, owing to the degradation of the natural components in the filler. The findings from DSC suggested that the crystallinity was affected. The tensile testing results indicated that the composites were appropriate for applications requiring low tensile strength at break and high Young’s modulus. A comparison of these results with earlier ones exhibited that the basic additives in the polymer may have an effect on the filler performance.


2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Negasi Gebremedhin ◽  
Gideon K. Rotich

Plastic has been a dominant material for packaging in recent years but due to its nonbiodegradability, it is causing environmental pollution. Among the plastics used, low-density polyethylene is used abundantly. These plastics can be removed from the environment by recycling into useful products through reinforcing it with natural textile fibers into composite materials. Natural fiber-based composites are ecofriendly and low cost. This research is aimed at manufacturing composite wall tiles from recycled low-density polyethylene reinforced with pineapple leaf fibers (PALF). The PALF was extracted by the retting process followed by mechanical scratching and treated with 5% NaOH to improve the fiber-matrix interaction. The composites were manufactured by the melt-mixing method followed by compression molding. The effects of fiber length and fiber weight proportion on composite properties were investigated using tensile, flexural, impact, and water absorption tests. The study showed that the optimum fiber weight proportion and fiber length for the optimal properties of the composite were achieved at 30% fiber weight proportion and 30 mm fiber length. The maximum tensile strength of 1562 N/mm2, flexural strength of 454.9 N/mm2, and impact strength of 225.2 J/mm2 were obtained. Water absorption of the tiles increased with the increase in both the fiber weight proportion and the fiber length.


2021 ◽  
Vol 11 (2) ◽  
Author(s):  
Chiedozie C. Aralu ◽  
Helen O. Chukwuemeka-Okorie ◽  
Kovo G. Akpomie

AbstractGongronema latifolium was used as a low-cost green inhibitor for mild steel by applying the weight loss method at 303–323 K. There was a decrease in percentage inhibition with temperature increase and a rise in inhibition efficiency with an increase in the concentration of inhibitor. The obtained results showed that Gongronema latifolium extract of methanol had percentage inhibition efficiencies in the range of 59.06–81.69%. Corrosion inhibition of mild steel showed a good fit to the Langmuir model compared to the Freundlich and El-Awardy adsorption models. Thermodynamics parameters, such as $$ E_{\text{a}} $$ E a , $$ Q_{\text{ads}} $$ Q ads and $$ \Delta G_{\text{ads}} $$ Δ G ads were evaluated and showed that the mechanism of corrosion inhibition of mild steel by methanol extract of Gongronema latifolium was physisorption. The results of this work indicated efficient potentials of the methanol extract of Gongronema latifolium as a low-cost corrosion inhibitor in acidic media for mild steel, which could be applied to reduce corrosion of metals in industries.


Author(s):  
Erguang Huo ◽  
Chao Liu ◽  
Liyong Xin ◽  
Yayun Zhang ◽  
Yunfeng Zhao ◽  
...  

High-efficiency and low-cost catalyst matters a great deal to convert solid wastes into high valued chemicals and biofuels. In this study, catalytic co-pyrolysis of wheat straw and low density polyethylene...


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