Read the following passage and answer the questions given after it. India generates at least 25,940 tonnes of plastic waste daily, equivalent to the weight of around 4,300 elephants. Of this, about 60% gets recycled, according to the Union environment ministry. The rest gets dumped in landfills, clogs drains, goes into the ocean as micro-plastics, or is burnt, leading to air pollution.

In the absence of a proper waste management system, the plastics that get recycled are often dirty, which makes the re-cycling process water-intensive and expensive. “It is the process of cleaning the plastics before recycling that makes it resource intensive. A lot of water is required to wash the collected plastics, especially if it is oily or greasy as it has to be cleaned with a solvent,” said Dr Suneel Pandey, director of environment and waste management, The Energy and Resources Institute (TERI).

Experts say proper waste collection and management is at the core of ensuring more plastics get recycled instead of ending up in landfills and oceans. Researchers from various institutes have come up with innovative ways to utilise the plastic waste that cannot be recycled further or are unrecyclable. At IIT Delhi, a group of chemical engineers are working on chemically breaking down plastics to its smaller hydrocarbon molecules and then synthesising diesel out of it. The process uses packaging material, Polyethylene terephthalate (PET) bottles, polystyrene, and multi-layer packaging.

The fuel produced can currently be used as a blend in stationary diesel machines like generators and needs further testing and standardisation to be used as commercial diesel in vehicles. A mix of plastic and stone has been used to create a block that can be used in flooring. A CSIR laboratory also used shredded plastics, chemically treated it and mixed with fillers to make tiles. A German chemical producer called BASF is also breaking down waste plastic and using it as raw material for chemicals, instead of using material derived from fossil fuels. One cost-effective solution was developed by Dr Rajagopalan Vasudevan, professor at Thiagarajar College of Engineering in Madurai. The National Highways Authority of India is currently scaling up his technology to use plastic waste in making roads.

He came up with the idea of mixing plastic waste with Bitumen used for constructing roads in 2001. “That year the Tamil Nadu government had planned to ban plastic and my concern began with the more than 1 lakh people employed by the industry. Since plastic is derived from petroleum just like Bitumen, I thought of using it for road construction. The result, not only plastic waste was getting utilised, the roads were cheaper and steadier,” he said. The plastic waste does not have to be segregated and even multi-layered plastics can be used in the mix. “All we need to do is collect the waste, dry it out and use it,” he said. The construction of every kilometre of road required nine tonnes of Bitumen and one tonne of plastic waste. This means for every kilometre of road, one-tonne Bitumen is saved, which costs about ₹30,000.

What has been developed by Dr Rajagopalan Vasudevan, professor at Thiagarajar College of Engineering in Madurai?

method for using plastic for road construction