- What is Plastic?
- How Plastics are produced?
- Types of Plastics
- Plastic processing Methods
- Consumption of Plastic worldwide
- Usage of Plastic in India
- Adverse Impacts
- Importing plastic waste despite oversupply in India
- Government’s effort to curb Plastic Pollution
- Plastic waste management rules
- Sustainable Plastic Waste Management Solutions
- How the concept of circular economy can be applied to curb Plastic pollution?
Plastic Pollution: How To Beat
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What is Plastic?
- Plastics are derived from natural, organic materials such as cellulose, coal, natural gas, salt and crude oil.
- Plastic was invented in New York in 1907 by Leo Baekeland.
- Due to their low cost, ease of manufacture, versatility, non-corrosiveness and imperviousness to water, plastics are used for multiple purposes at different scales.
- Further, many chemists, including Nobel laureate Hermann Staudinger (father of polymer chemistry) and Herman Mark (father of polymer physics), have contributed to the materials science of plastics.
How Plastics are produced?
- The production of plastics begins with the distillation of crude oil in an oil refinery which separates the heavy crude oil into groups of lighter components, called fractions.
- Each fraction is a mixture of hydrocarbon chains (chemical compounds made up of carbon and hydrogen), which differ in terms of the size and structure of their molecules.
- One of these fractions, naphtha, is the crucial compound for the production of plastics.
- Two main processes are used to produce plastics: Polymerisation and Polycondensation.
- In a polymerisation reactor, monomers such as ethylene and propylene are linked together to form long polymer chains.
Types of Plastics
Plastic processing Methods
- Extrusion – Plastic material is heated and forced out through a small opening to form the shape of the finished product. It is used to produce films, sheet, profiles, tubes, and pipes.
- Calendering – It is an extension of extrusion. The warm extrudate is chilled to create sheets. Heavy polyethylene films used for construction vapor and liquid barriers are calendered. High volume PVC films are typically made using calendars.
- Film Blowing – This process continuously extrudes vertically a ring of semi-molten polymer in an upward direction, like a fountain.
- Injection Molding – It can produce intricate three-dimensional parts of high quality and great reproducibility. It is predominately used for thermoplastics but some thermosets and elastomers are also processed by injection molding.
- Blow Molding – Blow molding is a process used in conjunction with extrusion or injection molding. This process is used to manufacture hollow plastic products and its principal advantage is its ability to produce hollow shapes without having to join two or more separately injection molded parts.
- Expanded Bead Blowing –Styrofoam expanded polystyrene thermal insulation board is made in a continuous extrusion process using expanded bead blowing.
- Rotational Molding – This process is used to make hollow configurations. Common rotationally molded products include shipping drums, storage tanks and some consumer furniture and toys.
- Compression Molding – This process has a prepared volume of plastic placed into a mold cavity and then a second mold is applied to squeeze the plastic into the desired shape.
- Casting – This process is the low pressure, often just pouring, addition of liquid resins to a mold.
- Thermoforming – Films of thermoplastic are heated to soften the film, and then the soft film is pulled by vacuum or pushed by pressure to conform to a mold.
Consumption of Plastic worldwide
- Worldwide, one million plastic bags and one million plastic bottles are used every minute.
- About 50% of plastic use is single use (disposable) and it constitutes 10% of the total waste generated.
- More than 9 billion tons of plastic are said to have been manufactured since the material was initially mass-produced in the 1950s.
- In 2015, of the nearly 7 billion tons of plastic waste generated, only 9% was recycled, 12% incinerated, and 79% accumulated in landfills or the environment.
- Each year, 13 million tonnes of plastic end up in the oceans.
- Drinking water samples analysed from 14 countries, including India, revealed that 83% have micro-plastics concentrations.
- African continent has the largest number of countries which have total ban on the production and use of plastic bags.
Usage of Plastic in India
- India consumes an estimated 16.5 million tonnes of plastic annually.
- Of this, 43% is plastic manufactured for single-use packaging material that will mostly find its way into garbage bins.
- 80% of total plastic produced in India is discarded.
- 60 cities across India generated over 15,000 tonnes of plastic waste every day.
- 20 rivers (mostly from Asia) carry two-thirds of plastic waste to the ocean. Among these rivers, Indus and Meghna (Brahmaputra) river carry second and sixth highest waste respectively.
- India’s annual plastic consumption is expected to cross 20 million tonnes in 2020.
- 94% of plastic waste generated is recyclable and belongs to the thermoplastics family, while the rest 6% are non-recyclable thermoset plastics.
- 67% of the plastic waste belonged to the HDPE/LDPE, 10% to PP, and 8.66% to PET amongst others.
- The average per capita consumption of plastic in India is about 11 kg, which is considerably low as compared to the global average of 28 kg.
- Plastic disposed of on land degrades slowly and its chemicals leach into the surroundings contaminating soil and water
- Plastics can pose significant ingestion, choking and entanglement hazards to wildlife.
- Plastic bags can choke waterways and exacerbate natural disasters. In 1988, poor drainage resulting from plastic bag litter clogging drains contributed to devastating floods in Bangladesh.
- Styrofoam items contain toxic chemicals such as styrene and benzene which considered carcinogenic and can lead to additional health complications.
- By blocking sewage systems and providing breeding grounds for mosquitoes, plastic can raise the risk of transmission of vector-borne diseases such as malaria.
- Plastic waste and microplastics, if ingested by fish or other marine life, can enter in food chain.
- As 95% of Styrofoam is air, it is not cost-effective to store or ship for recycling purposes. Moreover, because of the porosity of foamed plastic products, cleaning such products, is difficult and energy-intensive, further increasing the cost of recycling.
Importing plastic waste despite oversupply in India
- There are two main reasons why India generates so much plastic waste:
- i) The vast network of unlicensed units manufacturing low-grade plastic bags and other material such as styrofoam.
- ii) The indifference of municipal authorities to waste management.
- Plastic waste imports had increased from 12,000 tonnes in 2016-17 to 48,000 tonnes in 2017-18, despite a 2015 ban on plastic waste import.
- Before the re-imposition of the plastic waste import ban in March 2019, Indian recycling firms were importing plastic waste from China, Italy, Japan and Malawi as imported plastic waste is cheaper and available in segregated forms.
- The plastic companies were importing using the loophole of Special Economic Zones to import plastics. However, in March, 2019, the government put a ban on this as well.
Government’s effort to curb Plastic Pollution
- In order to address the plastic waste disposal and to ensure its scientific management, Plastic Waste Management Rules (PWR), 2011, was introduced under the Environment Protection Act, 1986.
- On the World environment day, Indian PM announced to join UN Environment’s Clean Seas campaign. As part of this commitment, the government will establish a national and regional marine litter action campaign as well as a program to measure the total marine plastic footprint in India’s coastal waters.
- In 2018, as the global host to UN World Environment Day, India had promised to phase out single-use plastic by 2022 with the theme ‘Beat Plastic Pollution’.
Plastic waste management rules
Highlights of Plastic Waste Management Rules, 2016
- Increase minimum thickness of plastic carry bags from 40 to 50 microns and stipulate minimum thickness of 50 microns for plastic sheets.
- Expand the jurisdiction of applicability from the municipal area to rural areas.
- It mandated the producers to devise a plan in consultation with the local bodies to introduce a collect back system known as the Extended Producers Responsibility (EPR).
- It introduced collection of plastic waste management fee through pre-registration of the producers, importers of plastic carry bags/multilayered packaging and vendors selling the same for establishing the waste management system.
Highlights of Plastic Waste Management (Amendment) Rules 2018
- The term ‘Non-recyclable multilayered plastic (MLP)’ was substituted by ‘Multilayered plastic which is non-recyclable or non-energy recoverable or with no alternate use’.
- Section 15 dealing with the pricing of carry bags is omitted. The rule earlier required vendors, who made plastic bags available, to register with the respective urban local body and pay a fee of `48,000 annually.
- It established a centralized registration system by mandating brand owners and producers operating in more than two states to register with the Central Pollution Control Board (CPCB).
Pricing of carry bags
- The Plastic Waste Management (Amendment) Rules 2018 remove the Rule 15 related to the pricing of plastic carry bags. It is envisaged that charging users for carry bags would be a key step towards initiating a behavioural change. However, studies have shown that in developing countries, a blanket ban may not be the best possible solution.
Enforcement of legislation
- Although the government has been proactive in terms of formulating rules, the implementation of a few inclusions has been a challenge.
- For instance, the PWR 2016 calls for the ban on the use of carry bags less than 50 microns in thickness. The effective implementation of this legislation has been a challenge for many municipalities due to demand of roadside hawkers owing to cheaper price.
Multilayered plastics (MLPs)
- MLP refers to any material used for packaging that has at least one layer of plastic as its main ingredient in combination with one or more layers of paper and aluminium foil either in the form of laminate or a co-extruded structure.
- Most companies prefer MLPs as they are three times more waterproof, light-weight, reduce shipping volume, and help in increasing the shelf life of products.
- However, recycling of this packaging remains expensive and a challenge owing to its multilayered properties.
- Plastic waste, especially carry bags is a major environment and public health problem in India, particularly in urban areas.
- In addition to being a visual harassment, plastic bags tend to clog drains, gutters, and rainwater vents, thereby creating a flood-like scenario even for sparse rains.
- Further, they also pose a danger to stray animals, such as cattle and dogs, who stand a good chance of consuming them.
- In India, dumping is a common practice, particularly due to the lack of awareness and the need for land to discard an enormous amount of wastes generated from our households and surrounding areas.
- Waste burning is a perennial problem that has been faced by municipalities around the country.
- Thick black smoke emanating from dumping grounds has become a commonly perceived sight. These practices have been one of the key reasons for the Delhi smog situation and the deterioration of the air quality indices in cities such as Varanasi.
Effect of toxic additives
- The main problems in the homogeneous plastics recycling are only related to the degradative phenomena occurring during recycling processes.
- These phenomena are generally much more problematic as compared to virgin polymers since the oxygenated groups formed during the processing accelerate the degradation of plastic materials, causing serious deterioration of end properties of the secondary materials.
- The recycled plastics are more harmful to the environment than the virgin products due to the mixing of additives, colours, stabilizers, halogenated flame retardants, and so on.
Number of times to be recycled
- A plastic can be recycled 7–9 times before it is no longer recyclable. A few polymers can only be recycled 1–2 times before they are down cycled into lesser-value products. The items that are down cycled (such as clothing) usually cannot be recycled and may eventually end up in a landfill.
Sustainable Plastic Waste Management Solutions
- Recycled plastics helps to address the pre-existing plastic waste problem and saves oil resources (every tonne of plastic waste recycled results in saving approximately 3.8 barrels of petroleum).
- Some of the key product sectors that contain post-consumer plastics include construction, furniture, landscaping, shipping, soft toys, and so on.
- Blending of recycled plastics with fillers and additives will enhance the strength and usability leading to value-added products.
- India has a huge potential in producing bioplastics due to the abundant availability of resources. According to a survey, about 63% of consumers are familiar with bio-based plastics.
- Bio-based products can be developed using different techniques and raw materials. One option is using recycled polymeric materials and blending them with biopolymers. Another approach is to develop the composites from only biopolymers without the incorporation of any kind of synthetic polymer.
- Pyrolysis is the breaking down of polymers into smaller molecules by thermal decomposition at temperatures close to 300 °C–400 °C in the presence of a catalyst (such as aluminium oxides, fly ash, red mud, and calcium hydroxide) in an inert atmosphere.
- The oil produced in pyrolysis process shows similarity to conventional diesel. Therefore, this may be an effective way to recycle plastic waste into fuels.
- Gasification of plastic waste has recently gained increased attention as thermo-chemical recycling technique.
- This process involves partial oxidation of plastic waste at high temperature. The main advantage of this process is the use of air as a gasification agent instead of oxygen alone. This makes gasification a simple technique with reduced operational costs.
- In this process, plastic materials are oxidized to produce a gaseous mixture containing carbon monoxide and hydrogen with minor quantities of hydrocarbons.
- This mixture is known as ‘syngas’ and can be used as a substitute for natural gas.
Co-processing of plastic
- Co-processing refers to the use of waste materials as an alternate fuel or raw material in industrial processes such as cement plants. Waste materials, such as plastic waste could be utilized as alternate fuel and raw material, thus substituting the use of coal.
- The government should restrict plastic production and encourage recycling through appropriate policies. The ‘Plastic Waste Management Rules 2016’ need to be strictly followed.
- There is need for behavioural change in order to act as responsible citizens with a determination towards maintaining cleaner surroundings.
- Every shopkeeper should encourage the use of biodegradable packing materials while shoppers should use cloth bags.
- Mass public awareness on the dangers of plastic hazards is also necessary.
- Eco-friendly substitutes (cloth/paper/jute bags, leaves/areca leaf plates, paper straws) should be developed. For this, scientific and financial support (soft loans and subsidies) is required.
- Before banning or levy on plastic comes into force, government should assess the availability of alternatives.
- Charges for plastic bag use and deposit-refund for plastic bottles may be effective options.
- Government should use revenues collected from taxes or levies on single-use plastics to maximize the public good and should support environmental projects or boost local recycling with the funds.
- There is a need for a real-time assessment and a state-wise mapping of producers, plastic demand and supply.
- In several countries, the introduction of Extended Producer Responsibility (EPR) and deposit-return schemes have proven effective in reducing littering from PET bottles. The initiative introduced by the PET Recycling Company (PETCO) in South Africa shows how the introduction of EPR (even when voluntary) can help develop local end-use markets for recycling.
- The price of biodegradable plastic products is higher than their synthetic plastic counterparts. Hence, tax exemptions, subsidies, and incentive based mechanisms are necessary to help boost the market for these products.
- The use of biodegradable plastic must be promoted, especially in large-scale applications, such as manufacturing of agricultural mulch films, superabsorbent composites used for waste water treatment, and sustained release of pesticides.
- On a long-term basis, issues such as different raw materials for developing synthetic polymers can also be investigated. A specific example involves the production of Nylon11 from castor beans.
- Manufacturers must consider the end-of-life impact of the product at the design stage itself known as the ‘Design for Environment’ concept.
- The consumers should also be educated by various forums, including schools to increase the awareness regarding plastics and the ensuing waste disposal issues.
- There is a lack of testing and certification facility to assess the quality of recycled plastic products. Hence, Research funding should be directed towards environmentally benign additives leading to the development of novel products.
- As a future strategy, plastic waste to fuel technology can be incorporated as a part of circular economy.
How the concept of circular economy can be applied to curb Plastic pollution?
- Plastic consumption is continuously increasing owing to urbanization and the growing global demand.
- A detailed mapping of waste quantities, generation sources, and the associated characteristics is vital for the implementation of an effective plastic waste management mechanism in cities.
- Plastic waste management has to be assessed on a case-to-case basis in conjunction with climate and geographical location.
- Development of high-performance and value added recycled products require the development of innovative solutions which focus on increased mechanical properties that are tailor-made to meet the special needs, such as recycled fire-retardant plastics.
- While recycling is the most suited model for tackling plastic waste as per the waste hierarchy, the implementation of the same is faced with challenges, such as a lack of source segregation and recovery.
- Hence, Sustainable plastic waste management solutions and alternatives calls for effective stakeholder engagement and capacity building.