Non-biodegradable Plastics Research Articles

Development and Characterization of Films for Food Application Incorporating Porphyran Extracted from Porphyra dioica

Non-biodegradable plastic is one of the biggest environmental problems of our lifetime and, considering the present societal needs, it will get worse. Consequently, there is an urgent need to develop sustainable and renewable alternatives to plastic, such as plastic-like materials obtained from biodegradable polymers, namely sulfated polysaccharides, considered one of the most viable alternatives. There is also a need to obtain these materials in an environmentally and economically sustainable way. The hereby developed process of obtaining film-forming solutions from semi-refined porphyran (PorphSR) uses a green solvent (hot water) with a high extraction yield of semi-refined porphyran (26.66 ± 0.27%) in a reproducible way and with low levels of contaminants. The obtained semi-refined porphyran showed good antioxidant potential in all tests performed: HPSA (Δ0.066 ± 0.002), DPPH (2.23 ± 0.78%), FRAP (0.420 ± 0.014 eq. ascorbic acid µg mg−1 of extract) and ABTS (20.46 ± 0.90%). After being cast into films, the most notable antioxidant properties were those of the semi-refined porphyran in the DPPH, FRAP and ABTS assays and of the pectin, (PorphSR_PcT and PorphSR_PcT_Gly) in the HPSA assay. Morphologically, the films showed relatively homogeneous and low roughness surfaces. It is concluded that the described method to obtain semi-refined porphyran is feasible and reproducible, and that the developed films, mainly PorfP2_PcT_Gly, proved to be a potential candidate for non-biodegradable plastic substitutes.

Evaluation of Biodegradabilities of Biosynthetic Polyhydroxyalkanoates in Thailand Seawater and Toxicity Assessment of Environmental Safety Levels.

Every year, thousands of tons of non-biodegradable plastic products are dumped into marine environments in Thailand’s territorial seawater, impacting various marine animals. Recently, there has been a surge in interest in biodegradable plastics as a solution for aquatic environments. However, in Thailand’s coastal waters, no suitable biodegradable plastic has been used as ocean-biodegradable packaging. Among them, polyhydroxyalkanoates (PHAs) have excellent biodegradability even in seawater, which is the desired property for packaging applications in tourist places such as plastic bags and bottles. In this report, we assess the environment’s safety and study the biodegradation in Thailand seawater of polyhydroxybutyrate (PHB) and PHA copolymer (PHBVV) that were successfully synthesized by bacteria with similar molecular weight. The two types of extracted PHA samples were preliminary biodegradability tested in the marine environment compared with cellulose and polyethylene. Within 28 days, PHB and PHBVV could be biodegraded in both natural and synthetic seawater with 61.2 and 96.5%, respectively. Furthermore, we assessed residual toxicity after biodegradation for environmental safety using seawater samples containing residual digested compounds and the standard guide for acute toxicity tests. It was discovered that marine water mites (Artemia franciscana) have 100 percent viability, indicating that they are non-toxic to the marine environment.

Upcycling hazardous metals and PET waste-derived metal–organic frameworks: a review on recent progresses and prospects

An intense increase in non-biodegradable plastics and waste metals is an immediate threat to the world and needs to be addressed urgently.

COVID-19: An Accelerator for Global Plastic Consumption and Its Implications.

Plastic has been ingrained in our society. Repercussions on the usage of nonbiodegradable plastics and their problems have been recently realized. Despite its detrimental environmental impact, the COVID-19 epidemic has compelled worldwide citizens to increase their plastic use due to affordability and availability. The volume of hospital solid waste, particularly plastics, is overgrowing due to an unexpected increase in medical waste, culminating in the global waste management catastrophe. Henceforth, adopting good waste management practices along with appropriate technologies and viewing the current issue from a fresh perspective would be an opportunity in this current scenario. Accordingly, this review study will focus on the plastic waste scenario before and during the COVID-19 epidemic. This review also disseminates alternative disposal options and recommends practical solutions to lessen human reliance on traditional plastics. Further, the responsibilities of various legislative and regulatory authorities at the local, regional, and worldwide levels are addressed.

Bio polymer based food packaging using composite materials

Heaps of non-biodegradable plastics for food and non-food purposes have become temperamental resources like petrol. By noticing hostile to oil choices and revealing insight into the nuts and bolts of moderating the impacts of nature, research has steadily moved to the formation of biodegradable food groups produced using biopolymer based materials. Nano fillers like MMT (montmorillonite) can be utilized to alter bio-Nano composites by consolidating normal biopolymers like starch and chitosan into biodegradable polymers. A food group with an antibacterial blend keeps microorganisms from laying eggs on various surfaces and expands the time furthest reaches of the genuine ease of use of the thing. The ideal part of antibacterial bio-Nano composites is that they are prescribed to be valuable in the food holding business.

Value-added products from waste plastics using dissolution technique

Non-biodegradable plastics polymers, such as low-density polyethylene (LDPE), polystyrene (PS), and polyvinyl chloride (PVC) are non-biodegradable and release toxic gases into the environment on combustion and after long use. This study includes the screening of a series of organic solvents for solubility parameters of LDPE and PS. The karanja biodiesel is also used as one of the solvents for the dissolution of plastics. In order to decide the best solvent to be used for the dissolution of plastic polymer, rate of dissolution, safety aspect, and cost of the solvent were considered. The solubility factor of LDPE and PS is found to be much closed to acetone, chlorobenzene, and karanja biodiesel. Out of them, karanja biodiesel is considered due to its environment friendly behavior. The output of the study is with three value-added products as high heating value fuel, good composite for low-density cement, and an oil-adsorbent. The dissolution products obtained are chemically analyzed using FTIR and GC–MS techniques to elucidate their composition. The BET and TGA techniques are used for physical analysis, viz., the porosity and thermal stability of the products respectively. The findings of dissolution methods in this article are compared with the conventional pyrolysis techniques for these plastics treatment.

Mechanical properties of fibre/ filler based poly(Lactic Acid) (Pla) composites : A brief review

Being a biodegradable polymer, poly(lactic acid) (PLA) based composites receive greater preference over non-biodegradable plastics. Poly(lactic acid) has to find its place in various applications such as polymer composites, agriculture, biomedical, etc. Polymer composites based on PLA possess comparable mechanical strength, endurance, flexibility and endures future opportunities. Several combinations of natural fibers and filler-based PLA composites have been fabricated and investigated for physical and mechanical changes. Moreover, several biopolymers and compatibilizers are added to PLA to provide rigidity. The paper presents a tabulated review of the various natural fiber/filter-based PLA composites and the preparation and outcomes. In addition, enhancement made by the reinforcement of nano filler in the PLA are also discussed in brief. The significance of PLA in the biomedical application has been discussed in brief. The paper also shed lights in the social and economic aspects of PLA.

Fusion of Chitin-Binding Domain From Chitinolyticbacter meiyuanensis SYBC-H1 to the Leaf-Branch Compost Cutinase for Enhanced PET Hydrolysis.

Polyethylene terephthalate (PET) is a mass-produced petroleum-based non-biodegradable plastic that contributes to the global plastic pollution. Recently, biocatalytic degradation has emerged as a viable recycling approach for PET waste, especially with thermophilic polyester hydrolases such as a cutinase (LCC) isolated from a leaf-branch compost metagenome and its variants. To improve the enzymatic PET hydrolysis performance, we fused a chitin-binding domain (ChBD) from Chitinolyticbacter meiyuanensis SYBC-H1 to the C-terminus of the previously reported LCCICCG variant, demonstrating higher adsorption to PET substrates and, as a result, improved degradation performance by up to 19.6% compared to with its precursor enzyme without the binding module. For compare hydrolysis with different binding module, the catalytic activity of LCCICCG-ChBD, LCCICCG-CBM, LCCICCG-PBM and LCCICCG-HFB4 were further investigated with PET substrates of various crystallinity and it showed measurable activity on high crystalline PET with 40% crystallinity. These results indicated that fusing a polymer-binding module to LCCICCG is a promising method stimulating the enzymatic hydrolysis of PET.

Microbial communities on biodegradable plastics under different fertilization practices in farmland soil microcosms

Plastic mulching is a common practice in agricultural systems and is often combined with fertilization. Biodegradable plastics (BPs) are becoming an alternative to non-biodegradable plastics (non-BPs) for soil mulching. However, the effects of fertilization on the microbial communities on BPs remain unclear. Here, we explored the responses of the plastisphere to different fertilization practices in soil-based microcosms containing three BPs: polylactic acid (PLA), poly (butylene succinate) (PBS), and poly (butylene-adipate-co-terephthalate) (PBAT), and one non-BP (low-density polyethylene, LDPE). The 16S and ITS rRNA gene-based Illumina sequencing method were used to identify the bacterial and fungal communities on the plastics and in the soils. Microbial community structure on BPs was significantly different from that in soils and on LDPE. The predicted functional profiles of bacteria on BPs, especially PBAT, were distinct from those in soils. The plastisphere communities on BPs were dominated by microbes adapted to access and utilize carbon sources compared with of the communities on LDPE. Application of manure increased the alpha diversity of bacterial communities on BPs but decreased it on LDPE. The structure of bacterial communities on BPs changed with the application of manure. Our research establishes the baseline dynamics of plastisphere communities on BPs in soils.

Phytotoxicity assessment of biodegradable and non-biodegradable plastics using seed germination and early growth tests

Global production of plastics remains at the high level despite the SARS-Cov-2 pandemic. These are primarily petroleum-derived plastics but the contribution of bio-based plastics estimated at the level of 1% in the plastic market in 2019 is expected to be increasing. Simultaneously, the significant part of plastic waste is still disposed improperly and pollutes the environment making a threat to all living organisms.In this work three plastic materials, two bio-based biodegradable: polylactide (PLA) and polyhydroxybutyrate (PHB), and one petroleum-derived non-biodegradable polypropylene (PP) were studied towards their effects on seed germination and early growth of higher plants. The following plants were used as bioindicators: monocotyledonous plant - Sorghum saccharatum and two dicotyledonous plants: Sinapsis alba and Lepidium sativum. Plastics did not affect seed germination of higher plants even at the highest concentration tested (11.9% w/w) but their presence in soil acted in various ways on growth of the plants. Either no or inhibitive or stimulation effects on growth of roots or stems were noticed. It depended on the concentration and chemical composition of the plastic tested, and plant species. PHB and PLA more often caused to the inhibition of root growth than PP did. This phenomenon was observed in particular with regard to the dicotyledonous plants.Moreover, in the tests with the dicotyledonous plants (S. alba and L. sativum) the dose-response relations were usually determined as statistically relevant. Among these plants cress (L. sativum) occurred to be more sensitive and allowed for obtaining the dose-response dependence for both root and stem length, and, what is important, it took place in the case of each of materials tested. Therefore, cress is recommended to be used as a bioindicator in the assessment of the effect of plastics (petroleum-derived and bio-based plastics) on the early stages of growth of higher plants.

Plasticor: Smarting Food Packages

Food waste that occurs at different stages from food production to transportation and in homes is an economic, social and environmental problem. These food scraps are largely responsible for the generation of greenhouse gases (GHG). In addition, many of these foods are sold in non-biodegradable plastic packaging that results in the accumulation of plastic in the environment, directly and/or indirectly affecting the lives of animals and humans. In order to bring about a possibility of reducing food waste and the accumulation of long-lasting plastics in nature, Plasticor was developed, a biodegradable and sustainable polymer used in the packaging of foods that use biosensors to test the viability for human consumption of food. A smart packaging that involves food and has its color changed when the product is no longer fit for consumption, indicating the presence of harmful microorganisms. Thus, avoiding the early disposal of food in good condition and consequently its impact on the environment, in addition to postponing the consumption of new products, Plasticor contributes to a more sustainable world.

Facile fabrication of porous waste-derived carbon-polyethylene terephthalate composite sorbent for separation of free and emulsified oil from water

Containment of oil spills in aquatic bodies and treatment of oily wastewater are necessary to mitigate oil pollution. Synthetic oil sorbents are commonly used for managing oil spills and while they are effective, their usage introduces a considerable amount of non-biodegradable plastic into the environment. In an effort to develop an inexpensive sorbent by reutilizing solid wastes for a sustainable future, this study investigates the fabrication of a composite oil sorbent from used polyethylene terephthalate bottles and waste carbonaceous residue from the gasification of oil refinery bottoms via an energy efficient phase inversion method. The composite sorbent demonstrated oil sorption capacity of ∼ 8 g/g, which is comparable to some commercially available adsorbents, and excellent retention capacity for mineral, paraffin and crude oils of different viscosities. Furthermore, the composite is able to remove oil from mineral or paraffin oil-in-water emulsions by sorption, with an efficacy of > 99.7 %, indicating its promising application in the treatment of industrial oily wastewater. Cost analysis shows that this waste-derived composite can be produced commercially at a competitive price.

Experimental Study on Properties of Concrete Using Shredded Plastic Waste and M-Sand as Partial Replacement of Fine Aggregate

Disposal of large quantity of plastic causes land, water, and air pollution etc.., so a study is conducted to recycle the plastic in concrete. This work investigates about the replacement of natural aggregate with non-biodegradable plastic aggregate made up of mixed shredded plastic waste in concrete. Several tests are conducted such as compressive strength of cube, compressive strength of cylinder, flexural strength test of prism to identify the properties and behavior of concrete using shredded plastic aggregate. Replacement of fine aggregate weight by 0%, 5%, 10%, 15%, 20% with shredded plastic fine (PF) aggregate and manufactured sand (M-Sand). Totally 30 cubes, 30 cylinders and 30 prisms are casted to identify the compressive strength, cylindrical compressive strength, and flexural strength respectively. Casted specimens are tested at 7, 14 and 28 days. The identified results from concrete using shredded plastic aggregate are compared with conventional concrete. Result shows that initially there is increase in mechanical properties then there is reduction in mechanical properties due to addition of shredded plastic aggregate added concrete. This reduction in strength is mainly due to poor bond strength between cement and shredded plastic aggregate.

Innovations in applications and prospects of bioplastics and biopolymers: a review.

Non-biodegradable plastics are continually amassing landfills and oceans worldwide while creating severe environmental issues and hazards to animal and human health. Plastic pollution has resulted in the death of millions of seabirds and aquatic animals. The worldwide production of plastics in 2020 has increased by 36% since 2010. This has generated significant interest in bioplastics to supplement global plastic demands. Bioplastics have several advantages over conventional plastics in terms of biodegradability, low carbon footprint, energy efficiency, versatility, unique mechanical and thermal characteristics, and societal acceptance. Bioplastics have huge potential to replace petroleum-based plastics in a wide range of industries from automobiles to biomedical applications. Here we review bioplastic polymers such as polyhydroxyalkanoate, polylactic acid, poly-3-hydroxybutyrate, polyamide 11, and polyhydroxyurethanes; and cellulose-based, starch-based, protein-based and lipid-based biopolymers. We discuss economic benefits, market scenarios, chemistry and applications of bioplastic polymers.

Compatibilization of Starch/Synthetic Biodegradable Polymer Blends for Packaging Applications: A Review

The health and environmental concerns of the usage of non-biodegradable plastics have driven efforts to explore replacing them with renewable polymers. Although starch is a vital renewable polymer, poor water resistivity and thermo-mechanical properties have limited its applications. Recently, starch/synthetic biodegradable polymer blends have captured greater attention to replace inert plastic materials; the question of ‘immiscibility’ arises during the blend preparation due to the mixing of hydrophilic starch with hydrophobic polymers. The immiscibility issue between starch and synthetic polymers impacts the water absorption, thermo-mechanical properties, and chemical stability demanded by various engineering applications. Numerous studies have been carried out to eliminate the immiscibility issues of the different components in the polymer blends while enhancing the thermo-mechanical properties. Incorporating compatibilizers into the blend mixtures has significantly reduced the particle sizes of the dispersed phase while improving the interfacial adhesion between the starch and synthetic biodegradable polymer, leading to fine and homogeneous structures. Thus, Significant improvements in thermo-mechanical and barrier properties and water resistance can be observed in the compatibilized blends. This review provides an extensive discussion on the compatibilization processes of starch and petroleum-based polymer blends.

Isolation of PHB Producing Yeast from Soil and its Quantification

Background: Plastics are widely used in almost every manufacturing industry ranging from automobiles to medicine. Plastics take years to get degrade and have become a threat to the environment. Therefore there is a necessity to use biodegradable plastics in place of such non-biodegradable plastics. Polyhydroxybutyrate or PHB is a type of biopolymer which has similar properties to that of synthetic plastics and is susceptible to degradation by microbes in the environment itself. PHB is produced in microorganisms such as bacteria or yeast under stress conditions. As the yeast has a large cell size, it can accumulate more PHB than bacteria and is also physiologically flexible, in addition to the advantage of using yeast rather than the bacterial cell for the production of PHB. Therefore, the aim of the study was to isolate PHB producing yeast strain from the agricultural field. Methods: Primary screening of isolates was performed using Sudan Black B for PHB production. The extraction of PHB was done using sodium hypochlorite digestion method. The quantification of extracted PHB was done by UV-VIS spectroscopy. Results: The percentage and amount of PHB extracted were found to be 13.4 % per biomass and 1.6mg/ml, respectively. Conclusion: A quite amount of PHB was able to be extracted from yeast isolate. As a future perspective, the enhancement of PHB production can be done using agricultural residues like sugarcane bagasse, corn cob, teff, banana peel, etc.

Polyolefins and Polystyrene as Chemical Resources for a Sustainable Future: Challenges, Advances, and Prospects

Nonbiodegradable plastics with inert and saturated C–C backbones comprise the majority of global annual plastics produced, including the ubiquitous polyolefins (polyethylene and polypropylene) and polystyrene. Unlike polymers with cleavable bonds, such as polyesters, polyurethanes, and polycarbonates, these inert plastics are the most challenging to upcycle and cannot be easily broken down by chemical or enzymatic means. Thus, they mostly end up in landfills or are incinerated to produce copious amounts of greenhouse emissions. In recent years, increased research effort has been focused toward the upcycling of low-value plastic waste to give them a new lease of life. However, the unreactive C–C polymer backbones of these plastics have posed formidable challenges for attempts at post-synthetic chemical functionalization and conversion into commodity chemicals. In this Perspective, we discuss these inert plastics as large untapped resources for the production of new functional polymeric materials and valuable industrially relevant feedstock, such as dicarboxylic acids and aromatic compounds. The exciting pioneering work featured herein will hopefully inspire a change in the way we view these waste plastics from a chemical dead-end to versatile raw materials, forming the basis of a more sustainable materials economy.

Durable Polylactic Acid (PLA)-Based Sustainable Engineered Blends and Biocomposites: Recent Developments, Challenges, and Opportunities

The paper comprehensively reviews durable polylactic acid (PLA)-based engineered blends and biocomposites supporting a low carbon economy. The traditional fossil fuel derived nonrenewable durable plastics that cannot be circumvented have spawned increased environmental concerns because of the continuous rise of their carbon footprint during processing and disposal. It is anticipated that the production of biodegradable and nonbiodegradable (durable) plastics from the year 2020 to 2025 will rise ∼47% and ∼21%, respectively. The carbon footprint can be reduced in durable (nonrenewable) plastics by decreasing or replacing the “fossil carbon” content with “renewable carbon” content. The replacement will enable us to attain a sustainable environment, a low carbon footprint, energy security, and effective resource management. Thus, PLA-based durable products need to be developed with an enhanced service life that strikes a balance between environment-friendliness and product performance for engineering high-performance applications. The recent progress for enhancing the durability of PLA-based products consisting of hybrid nonrenewable and renewable carbon has been attained by incorporating synthetic plastics, synthetic fibers (glass and carbon), natural fibers, and other biofillers (biocarbon). Further, the effects of additives such as initiators, nucleating agents, chain extenders, compatibilizers, impact modifiers, and toughening agents to prepare such blends and composites have been discussed. This Review further critically examines the advances centering on processability, heat resistance, flame retardancy, strength, and toughness. In addition to that, current and prospective applications such as automotive, electronic, medical, textile, and housing of PLA-based products are discussed. However, the challenges for tailoring durable PLA-based products that still need to be addressed, such as improved processability, striking stiffness–toughness balance, enhanced heat resistance, and improved interfacial adhesion between the polymer–polymer, polymer–filler, and hybrid polymer–filler in respective polymer blends, composites, and hybrid composites, are summarized and analyzed in this Review. Hence, the opportunities for improvement to overcome the challenges lie ahead.

Enhanced biodegradation of non-biodegradable plastics by UV radiation: Part 1

Optimum UV pretreatment of polystyrene (PS), polyethylene (PE) and polyethylene terephthalate (PET) plastics for their efficient biodegradation were evaluated in this study. It was found that a longer incubation time and shorter distance to UV source (t2d2 condition) (UV dose of 7.02 × 1012 μW·cm-2·s) resulted in a higher roughness, hydrophilicity, microbial viability, biofilm formation, surface degradation, and a more significant physical and molecular weight reduction. The highest biodegradation within 45 days happened to PE and PS with respective 7.8 and 5.13% physical weight loss, and 4.71 and 2.1 fold molecular weight reduction compared to the “un-pretreated & strain-free bio-treated” (control-3). The hydrophilicity of PS and PE were increased to the “UV-pretreated & bio-treated” samples with a reduction in water contact angle from 105° to 5° in PS and 102° to 60° in PE. Microscopic analysis indicated significant surface property changes or degradation (cracks and holes) on “UV-pretreated & bio-treated” samples. The thermal gravimetric analysis also showed 73, 25 and 20 °C reductions in degradation temperature of “UV-pretreated & bio-treated” PE, PS and PET, respectively. Chemical transformation revealed new peaks in “UV-pretreated & bio-treated” samples, indicating the positive role of UV in biodegradation efficiency. Statistics analysis showed that 45 days was adequate to obtain optimum biodegradation efficiency (p < 0.05).

Escalating SARS-CoV-2 circulation in environment and tracking waste management in South Asia.

The novel coronavirus disease of 2019 (COVID-19) pandemic has caused an exceptional drift of production, utilization, and disposal of personal protective equipment (PPE) and different microplastic objects for safety against the virus. Hence, we reviewed related literature on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA detected from household, biomedical waste, and sewage to identify possible health risks and status of existing laws, regulations, and policies regarding waste disposal in South Asian (SA) countries. The SARS-CoV-2 RNA was detected in sewage and wastewater samples of Nepal, India, Pakistan, and Bangladesh. Besides, this review reiterates the enormous amounts of PPE and other single-use plastic wastes generated from healthcare facilities and households in the SA region with inappropriate disposal, landfilling, and/or incineration techniques wind-up polluting the environment. Consequently, the Delta variant (B.1.617.2) of SARS-CoV-2 has been detected in sewer treatment plant in India. Moreover, the overuse of non-biodegradable plastics during the pandemic is deteriorating plastic pollution condition and causes a substantial health risk to the terrestrial and aquatic ecosystems. We recommend making necessary adjustments, adopting measures and strategies, and enforcement of the existing biomedical waste management and sanitation-related policy in SA countries. We propose to adopt the knowledge gaps to improve COVID-19-associated waste management and legislation to prevent further environmental pollution. Besides, the citizens should follow proper disposal procedures of COVID-19 waste to control the environmental pollution.