The helix of sustainability is a concept coined to help the manufacturing industry move to more sustainable practices by mapping its models of raw material use and reuse onto those of nature. The environmental benefits of the use crop origin sustainable materials have been assumed to be self-evident, but as the debate on food vs fuel shows, the whole product life cycle must be examined in the light of social and environmental effects in addition to technical suitability and profitability.
The helix of sustainability [1] [2] [3] is a concept created as a representation of the total systems approach to gain full advantage from manufacturing with sustainable materials, particularly biopolymers and biocomposites. In 2004, the concept was presented by Professor John Wood, then Chair of the Materials Foresight Panel at a DTI event hosted by the then Secretary of State for Industry (Jacqui Smith). [4] In the same year, it was also used in the European Science Foundation exploratory workshop on environmentally friendly composites. [5]
The advantages of working with crop origin raw materials are readily observed if the social and environmental impacts are considered as well as monetary cost (the Triple bottom line), and the helix of sustainability helps to demonstrate this. For the full potential of biopolymers to be realised it is essential that attention is paid to every aspect of the manufacturing process from design (how to cope with the uncertainties in properties associated with crop origin materials?), manufacture (can existing technologies be used?), through to end-of-life (can the redundant article be fed back into the materials cycle?). The entire supply chain must be considered because decisions taken at the design stage have significant effects right through the life of an article. Low-cost assembly techniques (e.g., snap-fits) may make dismantling or repair uneconomical. However, if say an easy-to-dismantle car is built, will there be any effect on the ability of the vehicle to absorb energy in a crash? At an even more fundamental level, what will be the social and environmental of the change in crop growing patterns? This low environmental impact approach to manufacturing is seen as an extension of waste reduction techniques, such as lean manufacturing.
Conventional cycles of use and reuse are circular. Consider the mechanical recovery of conventional polymers. A complex infrastructure is needed to recover the material at the end of an article's useful life. At the end of an article's life - say a PET carbonated drink bottle, the article must be separated from the waste stream, either by the consumer who throws it away, or by manual labour at the rubbish dump. It must then be transported to some facility to be reprocessed (using more labour and energy) back into a raw material. The heat and shear forces associated with the process of remanufacture tends to produce material with slightly degraded properties compared to the original material.
For sustainable material articles there is not such a great requirement for a dedicated recovery infrastructure. If a litter lout throws a crop origin biodegradable article on the ground, it will ultimately biodegrade into humus, water, and non-fossil CO2. If the article is placed into a compostable waste stream, the humus can then be used as fertiliser for the next generation of crops; there is also no requirement to sort biopolymer articles as there is with fossil polymer recycling. Note the difference between landfill and compost: the limited biological activity in landfill is slow and mostly anaerobic, resulting in the production of methane, whereas composting is a rapid aerobic process resulting in humus, water and non-fossil CO2. The energy bill for breaking down biodegradables into the fundamental building block molecules and then reassembling them into usable raw materials is large, but it uses direct solar energy rather than metered electricity. There is also no loss of properties with successive journeys through the cycle.
Biopolymers are natural polymers produced by the cells of living organisms. Like other polymers, biopolymers consist of monomeric units that are covalently bonded in chains to form larger molecules. There are three main classes of biopolymers, classified according to the monomers used and the structure of the biopolymer formed: polynucleotides, polypeptides, and polysaccharides. The Polynucleotides, RNA and DNA, are long polymers of nucleotides. Polypeptides include proteins and shorter polymers of amino acids; some major examples include collagen, actin, and fibrin. Polysaccharides are linear or branched chains of sugar carbohydrates; examples include starch, cellulose, and alginate. Other examples of biopolymers include natural rubbers, suberin and lignin, cutin and cutan, melanin, and polyhydroxyalkanoates (PHAs).
Biodegradation is the breakdown of organic matter by microorganisms, such as bacteria and fungi. It is generally assumed to be a natural process, which differentiates it from composting. Composting is a human-driven process in which biodegradation occurs under a specific set of circumstances.
Mycelium is a root-like structure of a fungus consisting of a mass of branching, thread-like hyphae. Its normal form is that of branched, slender, entangled, anastomosing, hyaline threads. Fungal colonies composed of mycelium are found in and on soil and many other substrates. A typical single spore germinates into a monokaryotic mycelium, which cannot reproduce sexually; when two compatible monokaryotic mycelia join and form a dikaryotic mycelium, that mycelium may form fruiting bodies such as mushrooms. A mycelium may be minute, forming a colony that is too small to see, or may grow to span thousands of acres as in Armillaria.
Industrial ecology (IE) is the study of material and energy flows through industrial systems. The global industrial economy can be modelled as a network of industrial processes that extract resources from the Earth and transform those resources into by-products, products and services which can be bought and sold to meet the needs of humanity. Industrial ecology seeks to quantify the material flows and document the industrial processes that make modern society function. Industrial ecologists are often concerned with the impacts that industrial activities have on the environment, with use of the planet's supply of natural resources, and with problems of waste disposal. Industrial ecology is a young but growing multidisciplinary field of research which combines aspects of engineering, economics, sociology, toxicology and the natural sciences.
A bio-based material is a material intentionally made, either wholly or partially, from substances derived from living organisms, such as plants, animals, enzymes, and microorganisms, including bacteria, fungi and yeast.
Polyhydroxyalkanoates or PHAs are polyesters produced in nature by numerous microorganisms, including through bacterial fermentation of sugars or lipids. When produced by bacteria they serve as both a source of energy and as a carbon store. More than 150 different monomers can be combined within this family to give materials with extremely different properties. These plastics are biodegradable and are used in the production of bioplastics.
Bioplastics are plastic materials produced from renewable biomass sources, such as vegetable fats and oils, corn starch, straw, woodchips, sawdust, recycled food waste, etc. Some bioplastics are obtained by processing directly from natural biopolymers including polysaccharides and proteins, while others are chemically synthesised from sugar derivatives and lipids from either plants or animals, or biologically generated by fermentation of sugars or lipids. In contrast, common plastics, such as fossil-fuel plastics are derived from petroleum or natural gas.
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.
Green waste, also known as "biological waste", is any organic waste that can be composted. It is most usually composed of refuse from gardens such as grass clippings or leaves, and domestic or industrial kitchen wastes. Green waste does not include things such as dried leaves, pine straw, or hay. Such materials are rich in carbon and considered "brown wastes," while green wastes contain high concentrations of nitrogen. Green waste can be used to increase the efficiency of many composting operations and can be added to soil to sustain local nutrient cycling.
Biodegradable waste includes any organic matter in waste which can be broken down into carbon dioxide, water, methane, compost, humus, and simple organic molecules by micro-organisms and other living things by composting, aerobic digestion, anaerobic digestion or similar processes. It mainly includes kitchen waste, ash, soil, dung and other plant matter. 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 sulfates which can be decomposed by sulfate reducing bacteria to yield hydrogen sulfide in anaerobic land-fill conditions.
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.
A biocomposite is a composite material formed by a matrix (resin) and a reinforcement of natural fibers. Environmental concern and cost of synthetic fibres have led the foundation of using natural fibre as reinforcement in polymeric composites. The matrix phase is formed by polymers derived from renewable and nonrenewable resources. The matrix is important to protect the fibers from environmental degradation and mechanical damage, to hold the fibers together and to transfer the loads on it. In addition, biofibers are the principal components of biocomposites, which are derived from biological origins, for example fibers from crops, recycled wood, waste paper, crop processing byproducts or regenerated cellulose fiber (viscose/rayon). The interest in biocomposites is rapidly growing in terms of industrial applications and fundamental research, due to its great benefits. Biocomposites can be used alone, or as a complement to standard materials, such as carbon fiber. Advocates of biocomposites state that use of these materials improve health and safety in their production, are lighter in weight, have a visual appeal similar to that of wood, and are environmentally superior.
Upcycling, also known as creative reuse, is the process of transforming by-products, waste materials, useless, or unwanted products into new materials or products perceived to be of greater quality, such as artistic value or environmental value.
This is a glossary of environmental science.
Sustainable packaging is the development and use of packaging which results in improved sustainability. This involves increased use of life cycle inventory (LCI) and life cycle assessment (LCA) to help guide the use of packaging which reduces the environmental impact and ecological footprint. It includes a look at the whole of the supply chain: from basic function, to marketing, and then through to end of life (LCA) and rebirth. Additionally, an eco-cost to value ratio can be useful The goals are to improve the long term viability and quality of life for humans and the longevity of natural ecosystems. Sustainable packaging must meet the functional and economic needs of the present without compromising the ability of future generations to meet their own needs. Sustainability is not necessarily an end state but is a continuing process of improvement.
Biodegradable bags are bags that are capable of being decomposed by bacteria or other living organisms.
Danimer Scientific, formerly known as Meredian Holdings Group Inc. and MHG, is a biopolymer manufacturer headquartered in Bainbridge, Georgia.
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.
Mubarak Ahmad Khan is a Bangladeshi scientist and a researcher in jute's commercial uses and possibilities. According to the science-based research database, Scopus, he is considered to be the leading scientist in the study of jute worldwide. He is currently serving as the Scientific Advisor of Bangladesh Jute Mills corporation (BJMC). Among his inventions are the Sonali Bag, Jutin, and helmets and tiles made from jute.
Amar K. Mohanty is a material scientist and biobased material engineer, academic and author. He is a Professor and Distinguished Research Chair in Sustainable Biomaterials at the Ontario Agriculture College and is the Director of the Bioproducts Discovery and Development Centre at the University of Guelph.