Last updated
Yellow slime mold growing on a bin of wet paper Slime.mold.jpg
Yellow slime mold growing on a bin of wet paper

Biodegradation is the breakdown of organic matter by microorganisms, such as bacteria and fungi. [lower-alpha 1] [2]

Bacteria A domain of prokaryotes – single celled organisms without a nucleus

Bacteria are a type of biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a number of shapes, ranging from spheres to rods and spirals. Bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit soil, water, acidic hot springs, radioactive waste, and the deep biosphere of the earth's crust. Bacteria also live in symbiotic and parasitic relationships with plants and animals. Most bacteria have not been characterised, and only about 27 percent of the bacterial phyla have species that can be grown in the laboratory . The study of bacteria is known as bacteriology, a branch of microbiology.



The process of biodegradation can be divided into three stages: biodeterioration, biofragmentation, and assimilation. [3] Biodeterioration is sometimes described as a surface-level degradation that modifies the mechanical, physical, and chemical properties of the material. This stage occurs when the material is exposed to abiotic factors in the outdoor environment and allows for further degradation by weakening the material's structure. Some abiotic factors that influence these initial changes are compression (mechanical), light, temperature, and chemicals in the environment. [3]  While biodeterioration typically occurs as the first stage of biodegradation, it can in some cases be parallel to biofragmentation. [4] Hueck, [5] however, defined Biodeterioration as the undesirable action of living organisms on Man's materials, involving such things as breakdown of stone facades of buildings, [6] corrosion of metals by microorganisms, or merely the esthetic changes induced on man-made structures by the growth of living organisms. [6]

Biological assimilation, or bio-assimilation, is the combination of two processes to supply cells with nutrients. The first is the process of absorption of vitamins, minerals, and other chemicals from food within the gastrointestinal tract. In humans this is always done with a chemical breakdown and physical breakdown. The second process of bio assimilation is the chemical alteration of substances in the bloodstream by the liver or cellular secretions. Although a few similar compounds can be absorbed in digestion bio assimilation, the bioavailability of many compounds is dictated by this second process since both the liver and cellular secretions can be very specific in their metabolic action. This second process is where the absorbed food reaches the cells via the liver.

Abiotic component non-living chemical and physical parts of the environment that affect living organisms and the functioning of ecosystems

In biology and ecology, abiotic components or abiotic factors are non-living chemical and physical parts of the environment that affect living organisms and the functioning of ecosystems. Abiotic factors and the phenomena associated with them underpin all biology.

Biofragmentation of a polymer is the lytic process in which bonds within a polymer are cleaved, generating oligomers and monomers in its place. [3] The steps taken to fragment these materials also differ based on the presence of oxygen in the system. The breakdown of materials by microorganisms when oxygen is present, it's aerobic digestion. And the breakdown of materials when oxygen is not present, is anaerobic digestion. [7] The main difference between these processes is that anaerobic reactions produce methane, while aerobic reactions do not (however, both reactions produce carbon dioxide, water, some type of residue, and a new biomass). [8] In addition, aerobic digestion typically occurs more rapidly than anaerobic digestion, while anaerobic digestion does a better job reducing the volume and mass of the material. [7] Due to anaerobic digestion's ability to reduce the volume and mass of waste materials and produce a natural gas, anaerobic digestion technology is widely used for waste management systems and as a source of local, renewable energy. [9]

Polymer Substance composed of macromolecules with repeating structural units

A polymer is a large molecule, or macromolecule, composed of many repeated subunits. Due to their broad range of properties, both synthetic and natural polymers play essential and ubiquitous roles in everyday life. Polymers range from familiar synthetic plastics such as polystyrene to natural biopolymers such as DNA and proteins that are fundamental to biological structure and function. Polymers, both natural and synthetic, are created via polymerization of many small molecules, known as monomers. Their consequently large molecular mass, relative to small molecule compounds, produces unique physical properties including toughness, viscoelasticity, and a tendency to form glasses and semicrystalline structures rather than crystals. The terms polymer and resin are often synonymous with plastic.

An oligomer is a molecular complex of chemicals that consists of a few repeating units, in contrast to a polymer, where the number of monomers is, in principle, infinite. Dimers, trimers, and tetramers are, for instance, oligomers composed of two, three, and four monomers, respectively.

A monomer is a molecule that can be reacted together with other monomer molecules to form a larger polymer chain or three-dimensional network in a process called polymerization.

The resulting products from biofragmentation are then integrated into microbial cells, this is the assimilation stage. [3] Some of the products from fragmentation are easily transported within the cell by membrane carriers. However, others still have to undergo biotransformation reactions to yield products that can then be transported inside the cell. Once inside the cell, the products enter catabolic pathways that either lead to the production of adenosine triphosphate (ATP) or elements of the cells structure. [3]

Adenosine triphosphate chemical compound

Adenosine triphosphate (ATP) is a complex organic chemical that provides energy to drive many processes in living cells, e.g. muscle contraction, nerve impulse propagation, and chemical synthesis. Found in all forms of life, ATP is often referred to as the "molecular unit of currency" of intracellular energy transfer. When consumed in metabolic processes, it converts either to adenosine diphosphate (ADP) or to adenosine monophosphate (AMP). Other processes regenerate ATP so that the human body recycles its own body weight equivalent in ATP each day. It is also a precursor to DNA and RNA, and is used as a coenzyme.

Anabolism is the set of metabolic pathways that construct molecules from smaller units. These reactions require energy, known also as an endergonic process. Anabolism is the building-up aspect of metabolism, whereas catabolism is the breaking-down aspect. Anabolism is usually synonymous with biosynthesis.

Aerobic biodegradation formula Aerobic biodegradition equation.png
Aerobic biodegradation formula
Anaerobic degradation formula Anaerobic biodegradition.svg
Anaerobic degradation formula

Factors affecting biodegradation rate

In practice, almost all chemical compounds and materials are subject to biodegradation processes. The significance, however, is in the relative rates of such processes, such as days, weeks, years or centuries. A number of factors determine the rate at which this degradation of organic compounds occurs. Factors include light, water, oxygen and temperature. [10] The degradation rate of many organic compounds is limited by their bioavailability, which is the rate at which a substance is absorbed into a system or made available at the site of physiological activity, [11] as compounds must be released into solution before organisms can degrade them.The rate of biodegradation can be measured in a number of ways. Respirometry tests can be used for aerobic microbes. First one places a solid waste sample in a container with microorganisms and soil, and then aerates the mixture. Over the course of several days, microorganisms digest the sample bit by bit and produce carbon dioxide – the resulting amount of CO2 serves as an indicator of degradation. Biodegradability can also be measured by anaerobic microbes and the amount of methane or alloy that they are able to produce. [12]

Light electromagnetic radiation in or near visible spectrum

Light is electromagnetic radiation within a certain portion of the electromagnetic spectrum. The word usually refers to visible light, which is the portion of the spectrum that can be perceived by the human eye. Visible light is usually defined as having wavelengths in the range of 400–700 nanometers (nm), or 4.00 × 10−7 to 7.00 × 10−7 m, between the infrared and the ultraviolet. This wavelength means a frequency range of roughly 430–750 terahertz (THz).

Water Chemical compound with formula H2O

Water is a transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere, and the fluids of most living organisms. It is vital for all known forms of life, even though it provides no calories or organic nutrients. Its chemical formula is H2O, meaning that each of its molecules contains one oxygen and two hydrogen atoms, connected by covalent bonds. Water is the name of the liquid state of H2O at standard ambient temperature and pressure. It forms precipitation in the form of rain and aerosols in the form of fog. Clouds are formed from suspended droplets of water and ice, its solid state. When finely divided, crystalline ice may precipitate in the form of snow. The gaseous state of water is steam or water vapor. Water moves continually through the water cycle of evaporation, transpiration (evapotranspiration), condensation, precipitation, and runoff, usually reaching the sea.

Oxygen Chemical element with atomic number 8

Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as well as with other compounds. By mass, oxygen is the third-most abundant element in the universe, after hydrogen and helium. At standard temperature and pressure, two atoms of the element bind to form dioxygen, a colorless and odorless diatomic gas with the formula O
. Diatomic oxygen gas constitutes 20.8% of the Earth's atmosphere. As compounds including oxides, the element makes up almost half of the Earth's crust.

It's important to note factors that affect biodegradation rates during product testing to ensure that the results produced are accurate and reliable. Several materials will test as being biodegradable under optimal conditions in a lab for approval but these results may not reflect real world outcomes where factors are more variable. [13] For example, a material may have tested as biodegrading at a high rate in the lab may not degrade at a high rate in a landfill because landfills often lack light, water, and microbial activity that are necessary for degradation to occur. [14] Thus, it is very important that there are standards for plastic biodegradable products, which have a large impact on the environment. The development and use of accurate standard test methods can help ensure that all plastics that are being produced and commercialized will actually biodegrade in natural environments. [15] One test that has been developed for this purpose is DINV 54900. [16]

Approximated time for compounds to biodegrade in a marine environment [17]
ProductTime to Biodegrade
Paper towel 2–4 weeks
Newspaper6 weeks
Apple core2 months
Cardboard box2 months
Wax coated milk carton 3 months
Cotton gloves1–5 months
Wool gloves1 year
Plywood 1–3 years
Painted wooden sticks13 years
Plastic bags 10–20 years
Tin cans 50 years
Disposable diapers 50–100 years
Plastic bottle 100 years
Aluminium cans 200 years
Glass bottles Undetermined
Time-frame for common items to break down in a terrestrial environment [14]
Vegetables5 days – 1 month
Paper2–5 months
Cotton T-shirt6 months
Orange peels6 months
Tree leaves1 year
Wool socks1–5 years
Plastic-coated paper milk cartons5 years
Leather shoes 25–40 years
Nylon fabric30–40 years
Tin cans50–100 years
Aluminium cans80–100 years
Glass bottles1 million years
Styrofoam cup 500 years to forever
Plastic bags500 years to forever


The term Biodegradable Plastics refers to a material that maintains its mechanical strength during practical use but break down into low-weight compounds and non-toxic byproducts after their use. [18] This breakdown is made possible through an attack of microorganisms on the material, which is typically a non-water-soluble polymer. [4] Such materials can be obtained through chemical synthesis, fermentation by microorganisms, and from chemically modified natural products. [19]

Plastics biodegrade at highly variable rates. PVC-based plumbing is selected for handling sewage because PVC resists biodegradation. Some packaging materials on the other hand are being developed that would degrade readily upon exposure to the environment. [20] Examples of synthetic polymers that biodegrade quickly include polycaprolactone, other polyesters and aromatic-aliphatic esters, due to their ester bonds being susceptible to attack by water. A prominent example is poly-3-hydroxybutyrate, the renewably derived polylactic acid. Others are the cellulose-based cellulose acetate and celluloid (cellulose nitrate).

Polylactic acid is an example of a plastic that biodegrades quickly. Polylactid sceletal.svg
Polylactic acid is an example of a plastic that biodegrades quickly.

Under low oxygen conditions plastics break down more slowly. The breakdown process can be accelerated in specially designed compost heap. Starch-based plastics will degrade within two to four months in a home compost bin, while polylactic acid is largely undecomposed, requiring higher temperatures. [21] Polycaprolactone and polycaprolactone-starch composites decompose slower, but the starch content accelerates decomposition by leaving behind a porous, high surface area polycaprolactone. Nevertheless, it takes many months. [22] In 2016, a bacterium named Ideonella sakaiensis was found to biodegrade PET.

Many plastic producers have gone so far even to say that their plastics are compostable, typically listing corn starch as an ingredient. However, these claims are questionable because the plastics industry operates under its own definition of compostable:

"that which is capable of undergoing biological decomposition in a compost site such that the material is not visually distinguishable and breaks down into carbon dioxide, water, inorganic compounds and biomass at a rate consistent with known compostable materials." (Ref: ASTM D 6002) [23]

The term "composting" is often used informally to describe the biodegradation of packaging materials. Legal definitions exist for compostability, the process that leads to compost. Four criteria are offered by the European Union: [24] [25]

  1. Chemical composition: volatile matter and heavy metals as well as fluorine should be limited.
  2. Biodegradability: the conversion of >90% of the original material into CO2, water and minerals by biological processes within 6 months.
  3. Disintegrability: at least 90% of the original mass should be decomposed into particles that are able to pass through a 2x2 mm sieve.
  4. Quality: absence of toxic substances and other substances that impede composting.

Biodegradable technology

Now biodegradable technology has become a highly developed market with applications in product packaging, production, and medicine. The biodegradation of biomass offers some guidances. [26] Polyesters are known to biodegrade. [27]

Oxo-biodegradation is defined by CEN (the European Standards Organisation) as "degradation resulting from oxidative and cell-mediated phenomena, either simultaneously or successively." Whilst sometimes described as "oxo-fragmentable," and "oxo-degradable" these terms describe only the first or oxidative phase and should not be used for material which degrades by the process of oxo-biodegradation defined by CEN: the correct description is "oxo-biodegradable."

By combining plastic products with very large polymer molecules, which contain only carbon and hydrogen, with oxygen in the air, the product is rendered capable of decomposing in anywhere from a week to one to two years. This reaction occurs even without prodegradant additives but at a very slow rate. That is why conventional plastics, when discarded, persist for a long time in the environment. Oxo-biodegradable formulations catalyze and accelerate the biodegradation process but it takes considerable skill and experience to balance the ingredients within the formulations so as to provide the product with a useful life for a set period, followed by degradation and biodegradation. [28]

Biodegradable technology is especially utilized by the bio-medical community. Biodegradable polymers are classified into three groups: medical, ecological, and dual application, while in terms of origin they are divided into two groups: natural and synthetic. [18] The Clean Technology Group is exploiting the use of supercritical carbon dioxide, which under high pressure at room temperature is a solvent that can use biodegradable plastics to make polymer drug coatings. The polymer (meaning a material composed of molecules with repeating structural units that form a long chain) is used to encapsulate a drug prior to injection in the body and is based on lactic acid, a compound normally produced in the body, and is thus able to be excreted naturally. The coating is designed for controlled release over a period of time, reducing the number of injections required and maximizing the therapeutic benefit. Professor Steve Howdle states that biodegradable polymers are particularly attractive for use in drug delivery, as once introduced into the body they require no retrieval or further manipulation and are degraded into soluble, non-toxic by-products. Different polymers degrade at different rates within the body and therefore polymer selection can be tailored to achieve desired release rates. [29]

Other biomedical applications include the use of biodegradable, elastic shape-memory polymers. Biodegradable implant materials can now be used for minimally invasive surgical procedures through degradable thermoplastic polymers. These polymers are now able to change their shape with increase of temperature, causing shape memory capabilities as well as easily degradable sutures. As a result, implants can now fit through small incisions, doctors can easily perform complex deformations, and sutures and other material aides can naturally biodegrade after a completed surgery. [30]

Biodegradation vs. composting

There is no universal definition for biodegradation and there are various definitions of composting, which has led to much confusion between the terms. They are often lumped together; however, they do not have the same meaning. Biodegradation is the naturally-occurring breakdown of materials by microorganisms such as bacteria and fungi or other biological activity. [31] Composting is a human-driven process in which biodegradation occurs under a specific set of circumstances. [32] The predominant difference between the two is that one process is naturally-occurring and one is human-driven.

Biodegradable material is capable of decomposing without an oxygen source (anaerobically) into carbon dioxide, water, and biomass, but the timeline is not very specifically defined. Similarly, compostable material breaks down into carbon dioxide, water, and biomass; however, compostable material also breaks down into inorganic compounds. The process for composting is more specifically defined, as it controlled by humans. Essentially, composting is an accelerated biodegradation process due to optimized circumstances. [33] Additionally, the end product of composting not only returns to its previous state, but also generates and adds beneficial microorganisms to the soil called humus. This organic matter can be used in gardens and on farms to help grow healthier plants in the future. [34] Composting more consistently occurs within a shorter time frame since it is a more defined process and is expedited by human intervention. Biodegradation can occur in different time frames under different circumstances, but is meant to occur naturally without human intervention.

This figure represents the different paths of disposal for organic waste. Organic Waste Disposal Streams.pdf
This figure represents the different paths of disposal for organic waste.

Even within composting, there are different circumstances under which this can occur. The two main types of composting are at-home versus commercial. Both produce healthy soil to be reused - the main difference lies in what materials are able to go into the process. [33] At-home composting is mostly used for food scraps and excess garden materials, such as weeds. Commercial composting is capable of breaking down more complex plant-based products, such as corn-based plastics and larger pieces of material, like tree branches. Commercial composting begins with a manual breakdown of the materials using a grinder or other machine to initiate the process. Because at-home composting usually occurs on a smaller scale and does not involve large machinery, these materials would not fully decompose in at-home composting. Furthermore, one study has compared and contrasted home and industrial composting, concluding that there are advantages and disadvantages to both. [36]

The following studies provide examples in which composting has been defined as a subset of biodegradation in a scientific context. The first study, "Assessment of Biodegradability of Plastics Under Simulated Composting Conditions in a Laboratory Test Setting," clearly examines composting as a set of circumstances that falls under the category of degradation. [37] Additionally, this next study looked at the biodegradation and composting effects of chemically and physically crosslinked polylactic acid. [38] Notably discussing composting and biodegrading as two distinct terms. The third and final study reviews European standardization of biodegradable and compostable material in the packaging industry, again using the terms separately. [39]

The distinction between these terms is crucial because waste management confusion leads to improper disposal of materials by people on a daily basis. Biodegradation technology has led to massive improvements in how we dispose of waste; there now exist trash, recycling, and compost bins in order to optimize the disposal process. However, if these waste streams are commonly and frequently confused, then the disposal process is not at all optimized. [40] Biodegradable and compostable materials have been developed to ensure more of human waste is able to breakdown and return to its previous state, or in the case of composting even add nutrients to the ground. [41] When a compostable product is thrown out as opposed to composted and sent to a landfill, these inventions and efforts are wasted. Therefore, it is important for citizens to understand the difference between these terms so that materials can be disposed of properly and efficiently.

Environmental and social effects

Plastic pollution from illegal dumping poses health risks to wildlife. Animals often mistake plastics for food, resulting in intestinal entanglement. Slow-degrading chemicals, like polychlorinated biphenyls (PCBs), nonylphenol (NP), and pesticides also found in plastics, can release into environments and subsequently also be ingested by wildlife. [42]

Rachel Carson, a notable environmentalist in the 1960s, provided one of the first key studies on the consequences associated with chemical ingestion in wildlife, specifically birds. In her work Silent Spring, she wrote on DDT, a pesticide commonly used in human agricultural activities. Birds that ate the tainted bugs, Carson found, were more likely to produce eggs with thin and weak shells. [43]

These chemicals also play a role in human health, as consumption of tainted food (in processes called biomagnification and bioaccumulation) has been linked to issues such as cancers, [44] neurological dysfunction, [45] and hormonal changes. A well-known example of biomagnification impacting health in recent times is the increased exposure to dangerously high levels of mercury in fish, which can affect sex hormones in humans. [46]

In efforts to remediate the damages done by slow-degrading plastics, detergents, metals, and other pollutants created by humans, economic costs have become a concern. Marine litter in particular is notably difficult to quantify and review. [47] Researchers at the World Trade Institute estimate that cleanup initiatives' cost (specifically in ocean ecosystems) has hit close to thirteen billion dollars a year. [48] The main concern stems from marine environments, with the biggest cleanup efforts centering around garbage patches in the ocean. In 2017, a garbage patch the size of Mexico was found in the Pacific Ocean. It is estimated to be upwards of a million square miles in size. While the patch contains more obvious examples of litter (plastic bottles, cans, and bags), tiny microplastics are nearly impossible to clean up. [49] National Geographic reports that even more non-biodegradable materials are finding their way into vulnerable environments - nearly thirty-eight million pieces a year. [50]

Materials that have not degraded can also serve as shelter for invasive species, such as tube worms and barnacles. When the ecosystem changes in response to the invasive species, resident species and the natural balance of resources, genetic diversity, and species richness is altered. [51] These factors may support local economies in way of hunting and aquaculture, which suffer in response to the change. [52] Similarly, coastal communities which rely heavily on ecotourism lose revenue thanks to a buildup of pollution, as their beaches or shores are no longer desirable to travelers. The World Trade Institute also notes that the communities who often feel most of the effects of poor biodegradation are poorer countries without the means to pay for their cleanup. [48] In a positive feedback loop effect, they in turn have trouble controlling their own pollution sources. [53]

Etymology of "biodegradable"

The first known use of biodegradable in a biological context was in 1959 when it was employed to describe the breakdown of material into innocuous components by microorganisms. [54] Now biodegradable is commonly associated with environmentally friendly products that are part of the earth's innate cycles like the carbon cycle and capable of decomposing back into natural elements.

See also


  1. The IUPAC defines biodegradation as "degradation caused by enzymatic process resulting from the action of cells" and notes that the definition is "modified to exclude abiotic enzymatic processes." [1]

Related Research Articles

Compost organic matter that has been decomposed

Compost is organic matter that has been decomposed in a process called composting. This process recycles various organic materials otherwise regarded as waste products and produces a soil conditioner.

Bioremediation is a process used to treat contaminated media, including water, soil and subsurface material, by altering environmental conditions to stimulate growth of microorganisms and degrade the target pollutants. In many cases, bioremediation is less expensive and more sustainable than other remediation alternatives. Biological treatment is a similar approach used to treat wastes including wastewater, industrial waste and solid waste.

Polyhydroxybutyrate (PHB) is a polyhydroxyalkanoate (PHA), a polymer belonging to the polyesters class that area of interest as bio-derived and biodegradable plastics. The poly-3-hydroxybutyrate (P3HB) form of PHB is probably the most common type of polyhydroxyalkanoate, but other polymers of this class are produced by a variety of organisms: these include poly-4-hydroxybutyrate (P4HB), polyhydroxyvalerate (PHV), polyhydroxyhexanoate (PHH), polyhydroxyoctanoate (PHO) and their copolymers.

Anaerobic digestion Processes by which microorganisms break down biodegradable material in the absence of oxygen

Anaerobic digestion is a collection of processes by which microorganisms break down biodegradable material in the absence of oxygen. The process is used for industrial or domestic purposes to manage waste or to produce fuels. Much of the fermentation used industrially to produce food and drink products, as well as home fermentation, uses anaerobic digestion.

Bioplastic plastics derived from renewable biomass sources

Bioplastics are plastic materials produced from renewable biomass sources, such as vegetable fats and oils, corn starch, straw, woodchips, sawdust, recycled food waste, etc. Bioplastic can be made from agricultural by-products and also from used plastic bottles and other containers using microorganisms. Common plastics, such as fossil-fuel plastics are derived from petroleum or natural gas. Not all bioplastics are biodegradable nor biodegrade more readily than commodity fossil-fuel derived plastics. Bioplastics are usually derived from sugar derivatives, including starch, cellulose, and lactic acid. As of 2014, bioplastics represented approximately 0.2% of the global polymer market.

A mechanical biological treatment (MBT) system is a type of waste processing facility that combines a sorting facility with a form of biological treatment such as composting or anaerobic digestion. MBT plants are designed to process mixed household waste as well as commercial and industrial wastes.

Polyethylene or polythene film biodegrades naturally, albeit over a long period of time. Methods are available to make it more degradable under certain conditions of sunlight, moisture, oxygen, and composting and enhancement of biodegradation by reducing the hydrophobic polymer and increasing hydrophilic properties.

Biodegradable waste includes any organic matter in waste which can be broken down into carbon dioxide, water, methane or simple organic molecules by micro-organisms and other living things by composting, aerobic digestion, anaerobic digestion or similar processes. In waste management, it also includes some inorganic materials which can be decomposed by bacteria. Such materials include gypsum and its products such as plasterboard and other simple organic sulfates which can decompose to yield hydrogen sulphide in anaerobic land-fill conditions.

Biodegradable plastic plastic that can be biodegraded

Biodegradable plastics are plastics that can be decomposed by the action of living organisms, usually microbes, into water, carbon dioxide, and biomass. Biodegradable plastics are commonly produced with renewable raw materials, micro-organisms, petrochemicals, or combinations of all three.

Digestate material remaining after the anaerobic digestion of a biodegradable feedstock

Digestate is the material remaining after the anaerobic digestion of a biodegradable feedstock. Anaerobic digestion produces two main products: digestate and biogas. Digestate is produced both by acidogenesis and methanogenesis and each has different characteristics.

PBAT is a biodegradable random copolymer, specifically a copolyester of adipic acid, 1,4-butanediol and terephthalic acid. PBAT is produced by many different manufacturers and may be known by the brand names ecoflex®, Wango,Ecoworld, Eastar Bio, and Origo-Bi. It is also called poly(butylene adipate-co-terephthalate) and sometimes polybutyrate-adipate-terephthalate or even just "polybutyrate". It is generally marketed as a fully biodegradable alternative to low-density polyethylene, having many similar properties including flexibility and resilience, allowing it to be used for many similar uses such as plastic bags and wraps. The structure of the PBAT polymer is shown to the right. It is depicted as a block co-polymer here due to the common synthetic method of first synthesizing two copolymer blocks and then combining them. However, it is important to note that the actual structure of the polymer is a random co-polymer of the blocks shown.

The following article is a comparison of aerobic and anaerobic digestion. In both aerobic and anaerobic systems the growing and reproducing microorganisms within them require a source of elemental oxygen to survive.

Biodegradable polymer

Biodegradable polymers are a special class of polymer that breaks down after its intended purpose by bacterial decomposition process to result in natural byproducts such as gases (CO2, N2), water, biomass, and inorganic salts. These polymers are found both naturally and synthetically made, and largely consist of ester, amide, and ether functional groups. Their properties and breakdown mechanism are determined by their exact structure. These polymers are often synthesized by condensation reactions, ring opening polymerization, and metal catalysts. There are vast examples and applications of biodegradable polymers.

OXO-biodegradation is biodegradation as defined by the European Committee for Standardization (CEN) in CEN/TR 1535–2006, as "degradation resulting from oxidative and cell-mediated phenomena, either simultaneously or successively". This degradation is sometimes termed "OXO-degradable", but this latter term describes only the first or oxidative phase of degradation and should not be used for material which degrades by the process of OXO-biodegradation as defined by CEN. The correct term is "OXO-biodegradable".

Mirel is a trade name for a polyhydroxyalkanoate-based biodegradable bioplastic made by Cambridge, Massachusetts based company Metabolix. From 2006 until 2012 it was commercialized by a joint venture between Metabolix and Archer Daniels Midland Company called Telles. Mirel bioplastic is certified soil and marine degradable, and has applications in injection molding, extrusion coating, cast film and sheet, blown film, and thermoforming.

Biodegradable bag

Biodegradable bags are bags that are capable of being decomposed by bacteria or other living organisms.

Plastic material of Joe Weller

Plastic is material consisting of any of a wide range of synthetic or semi-synthetic organic compounds that are malleable and so can be molded into solid objects.

The Jundiz recycling plant is located in the Basque Country, particularly in Vitoria-Gasteiz Jundiz Álava. This place is responsible for recycling the city garbage. The trash is converted by a physical-chemical or mechanical process to submit a substance or a product already used to a cycle of total or partial treatment for a commodity or a new product or raw materials from waste, introducing them back into life cycle. This occurs at the prospect of depletion of natural resources, macro economic and eliminate waste efficiently.

Biodegradable additives are additives that enhance the biodegradation of polymers by allowing microorganisms to utilize the carbon within the polymer chain as a source of energy. Biodegradable additives attract microorganisms to the polymer through quorum sensing after biofilm creation on the plastic product. Additives are generally in masterbatch formation that use carrier resins such as polyethylene (PE), polypropylene (PP), polystyrene (PS) or polyethylene terephthalate (PET).

Biodegradable athletic footwear is athletic footwear that uses biodegradable materials with the ability to compost at the end-of-life phase. Such materials include natural biodegradable polymers, synthetic biodegradable polymers, and biodegradable blends. The use of biodegradable materials is a long-term solution to landfill pollution that can significantly help protect the natural environment by replacing the synthetic, non-biodegradable polymers found in athletic footwear.


  1. Vert M, Doi Y, Hellwich KH, Hess M, Hodge P, Kubisa P, Rinaudo M, Schué F (2012). "Terminology for biorelated polymers and applications (IUPAC Recommendations 2012)". Pure and Applied Chemistry . 84 (2): 377–410. doi:10.1351/PAC-REC-10-12-04.
  2. Focht DD. "Biodegradation". AccessScience. doi:10.1036/1097-8542.422025.
  3. 1 2 3 4 5 Lucas N, Bienaime C, Belloy C, Queneudec M, Silvestre F, Nava-Saucedo JE (September 2008). "Polymer biodegradation: mechanisms and estimation techniques". Chemosphere. 73 (4): 429–42. Bibcode:2008Chmsp..73..429L. doi:10.1016/j.chemosphere.2008.06.064. PMID   18723204.
  4. 1 2 Muller R (2005). "Biodegradability of Polymers: Regulations and Methods for Testing" (PDF). In Steinbüchel A (ed.). Biopolymers. Wiley-VCH. doi:10.1002/3527600035.bpola012. ISBN   978-3-527-30290-1.
  5. Hueck, Hans (January 1966). "The biodeterioration of materials as part of hylobiology. Material und Organismen 1(1):5-34". Material und Organismen. 1: 5–34 via ISSN 00255270.
  6. 1 2 Allsopp, Dennis (2004). Introduction to Biodeterioration. Cambridge: Cambridge University Press. ISBN   9780511617065.
  7. 1 2 "Aerobic and Anaerobic Biodegradation" (PDF). Fundamentals of Aerobic & Anaerobic Biodegradation Process. Polimernet Plastik San. Tic. Ltd. Şti.
  8. Van der Zee M (2011). "Analytical Methods for Monitoring Biodegradation Processes of Environmentally Degradable Polymers".
  9. Klinkner BA (2014). "Anaerobic Digestion as a Renewable Energy Source and Waste Management Technology: What Must be Done for this Technology to Realize Success in the United States?". University of Massachusetts Law Review. 9: 68–96.
  10. Haider T, Völker C, Kramm J, Landfester K, Wurm FR (July 2018). "Plastics of the future? The impact of biodegradable polymers on the environment and on society". Angewandte Chemie (International Ed. In English). 58 (1): 50–62. doi:10.1002/anie.201805766. PMID   29972726.
  11. "Definition of BIOAVAILABILITY". Retrieved 2018-09-19.
  12. Jessop A (2015-09-16). "How is biodegradability measured?". Commercial Waste. Retrieved 2018-09-19.
  13. Adamcova D, Radziemska M, Fronczyk J, Zloch J, Vaverkova MD (2017). "Research of the biodegradability of degradable/biodegradable plastic material in various types of environments". Przegląd Naukowy. Inżynieria I Kształtowanie Środowiska. 26: 3–14. doi:10.22630/PNIKS.2017.26.1.01.
  14. 1 2 "Measuring biodegradability". Science Learning Hub. Retrieved 2018-09-19.
  15. Scott G, Gilead D, eds. (1995). Degradable Polymers. Netherlands: Dordrecht Springer. doi:10.1007/978-94-011-0571-2. ISBN   978-94-010-4253-6.
  16. Witt U, Yamamoto M, Seeliger U, Müller RJ, Warzelhan V (May 1999). "Biodegradable Polymeric Materials-Not the Origin but the Chemical Structure Determines Biodegradability". Angewandte Chemie. 38 (10): 1438–1442. doi:10.1002/(sici)1521-3773(19990517)38:10<1438::aid-anie1438>;2-u. PMID   29711570.
  17. "Marine Debris Biodegradation Time Line". C-MORE, citing Mote Marine Laboratory, 1993.
  18. 1 2 Ikada Y, Tsuji H (February 2000). "Biodegradable polyesters for medical and ecological applications" (PDF). Macromolecular Rapid Communications. 21 (3): 117–132. doi:10.1002/(sici)1521-3927(20000201)21:3<117::aid-marc117>;2-x.
  19. Flieger M, Kantorová M, Prell A, Rezanka T, Votruba J (January 2003). "Biodegradable plastics from renewable sources". Folia Microbiologica. 48 (1): 27–44. doi:10.1007/bf02931273. PMID   12744074.
  20. Kyrikou I, Briassoulis D (12 Apr 2007). "Biodegradation of Agricultural Plastic Films: A Critical Review". Journal of Polymers and the Environment. 15 (2): 125–150. doi:10.1007/s10924-007-0053-8.
  21. "Section 6: Biodegradability of Packaging Waste" (PDF). Retrieved 2014-03-02.
  22. Wu C (January 2003). "Physical properties and biodegradability of maleated-polycaprolactone/starch composite" (PDF). Polymer Degradation and Stability. 80 (1): 127–134. CiteSeerX . doi:10.1016/S0141-3910(02)00393-2.
  23. "Compostable". Retrieved 2014-03-02.
  24. "Requirements of the EN 13432 standard" (PDF). European Bioplastics. Brussels, Belgium. April 2015. Retrieved July 22, 2017.
  25. Breulmann M, Künkel A, Philipp S, Reimer V, Siegenthaler KO, Skupin G, Yamamoto M (2012). "Polymers, Biodegradable". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.n21_n01. ISBN   978-3527306732.
  26. Luzier WD (February 1992). "Materials derived from biomass/biodegradable materials". Proceedings of the National Academy of Sciences of the United States of America. 89 (3): 839–42. Bibcode:1992PNAS...89..839L. doi:10.1073/pnas.89.3.839. PMC   48337 . PMID   1736301.
  27. Gross RA, Kalra B (August 2002). "Biodegradable polymers for the environment". Science. 297 (5582): 803–7. Bibcode:2002Sci...297..803G. doi:10.1126/science.297.5582.803. PMID   12161646.
  28. Agamuthu P, Faizura PN (April 2005). "Biodegradability of degradable plastic waste". Waste Management & Research. 23 (2): 95–100. doi:10.1177/0734242X05051045. PMID   15864950.
  29. The University of Nottingham (September 13, 2007). "Using Green Chemistry to Deliver Cutting Edge Drugs". Science Daily.
  30. Lendlein A, Langer R (May 2002). "Biodegradable, elastic shape-memory polymers for potential biomedical applications". Science. 296 (5573): 1673–6. Bibcode:2002Sci...296.1673L. doi:10.1126/science.1066102. PMID   11976407.
  31. Gómez EF, Michel FC (December 2013). "Biodegradability of conventional and bio-based plastics and natural fiber composites during composting, anaerobic digestion and long-term soil incubation". Polymer Degradation and Stability. 98 (12): 2583–2591. doi:10.1016/j.polymdegradstab.2013.09.018.
  32. "Biodegradable Products Institute - Composting". Retrieved 2018-09-24.
  33. 1 2 Magdoff F (November 1993). "Building Soils for Better Crops". Soil Science. 156 (5): 371. Bibcode:1993SoilS.156..371M. doi:10.1097/00010694-199311000-00014.
  34. Morris S, Martin JP. "Humus". AccessScience. doi:10.1036/1097-8542.325510 . Retrieved 2018-09-24.
  35. Kranert M, Behnsen A, Schultheis A, Steinbach D (2002). "Composting in the Framework of the EU Landfill Directive". Microbiology of Composting. Springer Berlin Heidelberg. pp. 473–486. doi:10.1007/978-3-662-08724-4_39. ISBN   9783642087059.
  36. Martínez-Blanco J, Colón J, Gabarrell X, Font X, Sánchez A, Artola A, Rieradevall J (June 2010). "The use of life cycle assessment for the comparison of biowaste composting at home and full scale". Waste Management (Submitted manuscript). 30 (6): 983–94. doi:10.1016/j.wasman.2010.02.023. PMID   20211555.
  37. Starnecker A, Menner M (1996-01-01). "Assessment of biodegradability of plastics under simulated composting conditions in a laboratory test system". International Biodeterioration & Biodegradation. 37 (1–2): 85–92. doi:10.1016/0964-8305(95)00089-5.
  38. Żenkiewicz M, Malinowski R, Rytlewski P, Richert A, Sikorska W, Krasowska K (2012-02-01). "Some composting and biodegradation effects of physically or chemically crosslinked poly(lactic acid)". Polymer Testing. 31 (1): 83–92. doi:10.1016/j.polymertesting.2011.09.012.
  39. Avella M, Bonadies E, Martuscelli E, Rimedio R (2001-01-01). "European current standardization for plastic packaging recoverable through composting and biodegradation". Polymer Testing. 20 (5): 517–521. doi:10.1016/S0142-9418(00)00068-4.
  40. Akullian A, Karp C, Austin K, Durbin D (2006). "Plastic Bag Externalities and Policy in Rhode Island" (PDF). Brown Policy Review.
  41. Song JH, Murphy RJ, Narayan R, Davies GB (July 2009). "Biodegradable and compostable alternatives to conventional plastics". Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences. 364 (1526): 2127–39. doi:10.1098/rstb.2008.0289. PMC   2873018 . PMID   19528060.
  42. Webb H, Arnott J, Crawford R, Ivanova E, Webb HK, Arnott J, Crawford RJ, Ivanova EP (2012-12-28). "Plastic Degradation and Its Environmental Implications with Special Reference to Poly(ethylene terephthalate)". Polymers. 5 (1): 1–18. doi:10.3390/polym5010001.
  43. Rosner D, Markowitz G (January 2013). "Persistent pollutants: a brief history of the discovery of the widespread toxicity of chlorinated hydrocarbons". Environmental Research. 120: 126–33. Bibcode:2013ER....120..126R. doi:10.1016/j.envres.2012.08.011. PMID   22999707.
  44. Kelly BC, Ikonomou MG, Blair JD, Morin AE, Gobas FA (July 2007). "Food web-specific biomagnification of persistent organic pollutants". Science. 317 (5835): 236–9. Bibcode:2007Sci...317..236K. doi:10.1126/science.1138275. PMID   17626882.
  45. Passos CJ, Mergler D (2008). "Human mercury exposure and adverse health effects in the Amazon: a review". Cadernos de Saude Publica. 24 Suppl 4: s503–20. doi:10.1590/s0102-311x2008001600004. PMID   18797727.
  46. Rana SV (July 2014). "Perspectives in endocrine toxicity of heavy metals--a review". Biological Trace Element Research. 160 (1): 1–14. doi:10.1007/s12011-014-0023-7. PMID   24898714.
  47. Newman S, Watkins E, Farmer A, Brink Pt, Schweitzer J (2015). "The Economics of Marine Litter". Marine Anthropogenic Litter. Springer International Publishing. pp. 367–394. doi:10.1007/978-3-319-16510-3_14. ISBN   978-3-319-16509-7.
  48. 1 2 Matsangou E (2 July 2018). "Counting the cost of plastic pollution". World Finance. Retrieved 17 September 2018.
  49. Rochman CM, Cook AM, Koelmans AA (July 2016). "Plastic debris and policy: Using current scientific understanding to invoke positive change". Environmental Toxicology and Chemistry. 35 (7): 1617–26. doi:10.1002/etc.3408. PMID   27331654.
  50. Montanari S (2017-07-25). "Plastic Garbage Patch Bigger Than Mexico Found in Pacific". National Geographic. Retrieved 2018-09-17.
  51. Gregory MR (July 2009). "Environmental implications of plastic debris in marine settings--entanglement, ingestion, smothering, hangers-on, hitch-hiking and alien invasions". Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences. 364 (1526): 2013–25. doi:10.1098/rstb.2008.0265. PMC   2873013 . PMID   19528053.
  52. Villarrubia-Gómez P, Cornell SE, Fabres J (2018-10-01). "Marine plastic pollution as a planetary boundary threat – The drifting piece in the sustainability puzzle". Marine Policy. 96: 213–220. doi:10.1016/j.marpol.2017.11.035.
  53. Hajat A, Hsia C, O'Neill MS (December 2015). "Socioeconomic Disparities and Air Pollution Exposure: a Global Review". Current Environmental Health Reports. 2 (4): 440–50. doi:10.1007/s40572-015-0069-5. PMC   4626327 . PMID   26381684.
  54. "Definition of BIODEGRADABLE". Retrieved 2018-09-24.

Standards by ASTM International