Plastics are materials which are 100 years old. In terms of material evolution, it is a very infant material. Yet it has grown 20 times in these 50 years. 320 million tonnes of plastic get produced. What happens to this plastic?
The discarded plastic goes in various streams such as landfills, energy recovery and some get cascaded into material recovery. But there is significant amount of leakage that happens giving plastic a bad name.
Marine littering is one of the problems when it comes to dumping of plastic. The recent origin of concern is the presence of micro plastics. These are micron level plastics that enter into the aquatic species and cause harms which can be dangerous for the species as well as to the food chain. There are 600 aquatic species which are endangered and 15% of which are on the verge of extinction.
Therefore, all stakeholders need to move from the wasteful linear economy towards circular economy. Earlier, in linear economy it was make, use and throw. Then came in chain economy, where a part of recycling materials were included. In circular economy, all the materials will be recycled and used with no chance of leakage in the system.
Strategies and Practices for management of Plastics waste
The projected population will be around 10 billion till 2050, which is a 40% increase of population as of today. Which means that many more people are going to consume plastics and eventually dispose it too.
1. Reduce plastic production
2. Innovative materials and product design
3. Reduce waste generation
4. Improve global waste management
5. Improve litter capture
6. Reduce input concentrations
Plastics Recycling: Options for value recovery
The recovery can happen on two levels – Material recovery and Energy recovery.
Material recovery includes mechanical recycling which results in semi-finished or finished products. Feedstock recycling which is for chemical raw materials (monomers or other chemicals in gas, liquid or solid form). And last one is biological recycling which gives compost and methane.
Energy recovery produces heat which is direct and controlled combustion.
Perspective for India
In India, the CPCB (Central pollution control board) has classified recycling in various fore folds. It derives primarily from US EPA classification, but the Government of India has gone ahead and redefined the rules and regulations.
As per the US approach:
1. Primary recycling – Pre-consumer industrial scrap to form new packaging
2. Secondary recycling – Postconsumer, physical reprocessing (grinding & melting) and reformation
3. Tertiary recycling – Post-consumer, chemical recycling to isolate components and reprocessed for use in manufacture
As per the Indian approach:
1. Primary recycling – Processing into products with similar characteristics to original product
2. Secondary recycling – Processing into products with different characteristics to original product
3. Tertiary recycling – Production of basic chemicals and fuels
4. Quaternary recycling – Retrieval of energy by burning/incineration
Real Indian Scenario
When you look at garbage, plastics constitute a minuscule part of waste. Although it is visible, it is less to 4% to 5% of any municipal aggregated dumped waste. However, in the case of PET bottles, whatever is picked up is converted into staple fibres, yarns, textile articles, strappings, pillows, etc. For other plastics, whatever is picked up, can be used in roads and for making plastone blocks.
Once retrieved, finding solutions to managing that waste is relatively lesser of a challenge than reining in the retrieval problem.
Peculiar challenges in India:
There is a need for smaller packages and for affordable savings such as sachets, pouches for shampoos, gutkhas, etc. These are probably not found in any part of the world. It’s easy for such small packages to be thrown off and difficult to be retrieved.
Lack of civic sense and worse is pilferage of public conveniences.
The entrenched habit of monetizing for example sotring and extracting value out of newspapers, old clothes, etc
Sustainability innovations – utilizing the USPs of Polymers
• Transition temperatures
• Molecular weight
Right-weighting, strength, etc.
e.g. learn from UHMWPE, DUHMWPE
• Enzyme-interacting Material Management Novel collection methods
• At-source collection/segregation methodologies
Polymers offer unique material properties that could be used to redesign plastic materials. We need to understand thoroughly whether they give solutions or just the goals.
As India’s population is growing, it is going to be a major concern for designing every material for consumption. Usage and disposal is also one of the factor as the society would not tolerate it. Whether judiciary, bureaucrats, or industrialists or common man, people are going to revolt. Presently, there are 21 cases going on against plastics. So, the industry will not find it easy to survive in such hostile environment. In addition, lot of government restrictions will also be on the horizon. Some of these things happened due to ill-informed premises (such as leaching) and some due to genuine issues such as littering, micro-plastics.
So, materials of convenience such as plastics should not become materials of nuisance. Therefore, until people realize that used material is not waste – it is a raw material – we are not going to be able to handle this problem. With growing population there is going to be an increase in consumption which needs to be matched with growing responsibility. New age materials such as plastics will need new discipline and governance methods and new technologies.