Ganga, the life source of Northern and Eastern India is a prominent area of study by researchers from diverse disciplines, a key among them is the environment. In 2019, the National Geographic Society organized the expedition “Sea to Source: Ganges” to scientifically document plastic waste in the Ganges watershed and support holistic and inclusive solutions. A proud partner in this women scientists-led expedition was IIT Kharagpur along with the Isabela Foundation, University of Dhaka, the Wildlife Institute of India, and Wild Team Bangladesh.
Researchers and students from an environment-focused group at the Dept. of Civil Engineering, IIT Kharagpur participated in this transboundary expedition. The group was involved in estimating the mismanaged plastic quantities from municipal solid waste all along the river in India and come up with potential solutions and improvements in waste management systems to avoid the leakages of plastic waste from land to the river.
Talking about their role in the study-based expedition, Prof. Brajesh Dubey who heads this group at IIT Kharagpur said, “We carried out the waste characterization from the city/town dumpsite waste samples, as well as the samples collected along the river from Rishikesh to Howrah. It helped in estimating the extent of mismanaged plastics in the waste, the type of plastics present in the waste and the estimation of the fraction of mismanaged waste plastics getting into the river Ganga. A model is also being developed using the field data to have a realistic estimation of the plastic pollution transport from land to river and eventually to the ocean.”
The IIT research group also performed a photographic survey of waste management practices and issues for each city/town. Further, they held and discussions with city officials on waste management plans, identification of infrastructure gaps for the city/town and suggestions for improvement in the implementation of the solutions for better plastic waste management. The solutions proposed include the proper waste collection in segregation mode, capacity building in terms of infrastructure development as well as skill improvement of manpower involved in waste management practices at ULB levels. The research group is in touch with several ULBs for the improvement of their waste management infrastructure.
While the expedition was carried out from May to December 2019, the study was carried out till February 2021. The report has been recently made public by the National Geographic Society on their blog. Read More
Are you throwing away the cucumber peels after preparing your salad? You may soon have them back in your kitchen as the eco-friendly packaging material for food items.
IIT Kharagpur researchers have developed cellulose nanocrystals from cucumber peels with high cellulose content, compared to other peel wastes, which can be used to create food packaging materials.
While single-use plastic is consciously being avoided by consumers, they still remain largely in circulation as food packaging items. Natural biopolymers are unable to make way in this industry as they lack strength, elongation, barrier property, optical property, and in some cases even biological safety. The cellulose nanomaterial developed by researchers, Prof. Jayeeta Mitra and N. Sai Prasanna at IIT Kharagpur’s Dept. of Agricultural and Food Engineering from raw cucumber waste, has addressed this challenge.
What are cellulose nanocrystals?
Food packaging materials require nano-filler reinforced bio-composites which can be derived from the cellulose widely available from the outer skin of fruits and vegetables. These cellulose fibres can be used to produce cellulose nanocrystals (CNCs), bio-based nanomaterials with defined nano-scale structural dimensions. They are produced through controlled acid hydrolysis which removes amorphous regions, and produces more crystalline regions.
Cucumber-based CNCs Developed by IIT Kharagpur Researchers
In India, cucumber finds wide use in salads, pickles, cooked vegetables or consumed raw and also in the beverage industry leading to a large volume of peel biowaste which is rich in cellulose content.
“Cucumbers generate about 12% residual wastes obtained after processing either the peels or whole slices as waste. We have used the celluloses, hemicellulose, pectin extracted from this processed material for deriving new bio-materials which are useful as nano-fillers in bio-composites,” said Dr. Jayeeta Mitra, Assistant Professor at the Dept. of Agricultural and Food Engineering.
Talking about the findings, she further added, “Our study shows that cellulose nanocrystals derived from cucumber peels possess modifiable properties due to the presence of abundant hydroxyl groups, which resulted in better biodegradability and biocompatibility. These nanocellulose materials emerged as strong, renewable and economic material of the near future, due to unique properties like a high surface area to volume ratio, light in weight, and excellent mechanical properties. Thereby, such nanocrystals, when reinforced as nano-fillers in bio-composites films, can produce effective food packaging materials with low oxygen permeabilities.”
The present study revealed that cucumber peels possessed greater cellulose content (18.22%) than other peel waste. It also provided better insights into their crystalline, thermal and colloidal properties of cucumber cellulose.
Research scholar N. Sai Prasanna said, “The crystallinity percentage as high as 74.1 % along with thermal stability of more than 200 °C negative zeta potential values (< -30 mV), and acid hydrolysis yield of 65.55%, make the material a strong nano-filler reinforcement as bio-nano composite. This offers the much needed mechanical, barrier, optical, rheological properties, nontoxicity, etc. required for food packaging materials which has the strong market potential to replace plastic.”
Market Potential – Application of CNCs and Environmental Sustainability
This non-toxic, biodegradable and biocompatible product has no adverse effects on health and the environment hence could have a huge market potential by rendering management of organic waste with high cellulose content profitable.
“Apart from the food packaging and beverage industries the researchers are optimistic about its scope in various fields like thermo-reversible and tenable hydrogels making, paper making, coating additives, food packaging materials, bio-composites, optically transparent films, as stabilizers in oil-water emulsion. Also, CNCs find good potential applications in biopharmaceutical applications such as drug delivery and fabricating temporary implants like sutures, stents etc.,” added Sai Prasanna.
The researchers further made a note for packaging industry players in our country for substantial investments to improve packaging material properties for better sustainability, disposal and decomposition issues. All these demands for biodegradable packaging will propel the nanocellulose market in the coming timeframe contributing towards a sustainable and plastic-free world, opined Prof. Mitra.
“The incremental usage of petroleum-based plastics in food packaging, spanning a few decades, has raised many challenges as these plastics are the indomitable sources of environmental pollution since nearly 60% of it is converted to landfill, and rest is recycled only once. More research and product development focused on various biopolymers from either macromolecules or from the microbial polymers would be able to make the sector acceptable to packing material producers with wider awareness, alternative products at economic prices,” she remarked.
Cite this paper: Prasanna, N. S., & Mitra, J. (2020). Isolation and characterization of cellulose nanocrystals from Cucumis sativus peels. Carbohydrate Polymers, 247, 116706. https://doi.org/10.1016/j.carbpol.2020.116706
IIT Kharagpur has the sole distinction of having a department in the area of Agricultural & Food Engineering, which comprises six disciplines such as Farm Machinery and Power, Land and Water Resources Engineering, Agricultural Biotechnology, Food Process Engineering, Agricultural Systems Management and Aquacultural Engineering, respectively. The major domain of research and development includes Precision agriculture, biofuel and bioenergy, modern food processing, plasticulture and micro-irrigation, Climate Change, hydrological modeling, groundwater management, water management, agricultural biotechnology, pollution abatement, extrusion technology, intelligent and high-pressure packaging, soil mapping and image analysis for plant phenotyping. Sponsored research projects and development activities deal with Integrated Rainwater Management, Soil Tillage, Utilisation of Fly ash, Ergonomic Database for Agricultural Equipment, Integrating Remote Sensing Data with Distributed Hydrological Models, Model Pilot Plant and koji room facilities for the production of industrial enzymes etc. More info . . .
IIT Kharagpur Research Gives Evidence of Microplastic Pollution in the Hot Liquid Consumed from Disposable Paper Cups
With the current crusade against single-use plastic, disposable paper cups are on the rise especially for consuming water and hot beverages. But even these cups are not without peril. Recent research by IIT Kharagpur has confirmed contamination of the hot liquid served in paper cups due to the degradation of microplastics and other hazardous components from the lining material of the cup.
Paper cups are usually lined by a thin layer of hydrophobic film which is made of mostly plastic (polyethylene) and sometimes co-polymers to hold the liquid in the paper cup. Within 15 minutes this microplastic layer degrades as a reaction to hot water, says the first of its kind study conducted in India by Dr. Sudha Goel, Associate Professor at the Dept. of Civil Engineering and research scholars Ved Prakash Ranjan and Anuja Joseph studying Environmental Engineering and Management.
The paper ‘Microplastics and other harmful substances released from disposable paper cups into hot water’ has been published in the Journal of Hazardous Materials recently. [https://doi.org/10.1016/j.jhazmat.2020.124118].
“According to our study, 25,000 micron-sized (10 µm to 1000 µm) microplastic particles are released into 100 mL of hot liquid (85 – 90 oC) residing in the paper cups for 15 mins. Thus, an average person drinking 3 regular cups of tea or coffee daily, in a paper cup, would be ingesting 75,000 tiny microplastic particles which are invisible to the human eyes,” says Prof. Sudha Goel.
The researchers followed two different procedures – in the first process, hot ultrapure (MilliQ) water (85–90 ◦C; pH~6.9) was poured into the disposable paper cups, and it was allowed to sit for 15 mins. The homogeneously mixed water was then analyzed for the presence of microplastics as well as additional ions that may have leached into the liquid from the paper cups. In the second process, paper cups were initially dipped in lukewarm (30–40 °C) MilliQ water (pH~6.9). Thereafter the hydrophobic film was carefully separated from the paper layer and exposed to hot MilliQ water (85–90 °C; pH~6.9) for 15 mins. and Changes in the physical, chemical, and mechanical properties of the plastic films were examined before and after exposure to hot water.
Explaining the exposure of 15 minutes, Prof. Goel linked its basis to a survey wherein the respondents confirmed consuming their beverage within 15 mins of obtaining it.
“Besides the result of the survey, it was also observed that within this time, the beverage attained the ambient temperature,” she said.
The samples of paper cups were collected from popular stores across Kharagpur, West Bengal. “Our study indicates most plastic layers lining the paper cups were of HDPE (High-density polyethylene) grade, whereas only very few paper cups were lined with a copolymer of cellulose. However, the release of microplastics into the hot water was consistent in all samples irrespective of their grades,” remarked researcher Ved Prakash Ranjan.
Apart from the presence of ions, the study also revealed that the plastic layer was laden with toxic heavy metals like Palladium, Chromium, and Cadmium.
“Our hypothesis on the degradation of the plastic layer after exposure to hot water was confirmed through images obtained from the atomic force and scanning electron microscopy. Also, another study on the mechanical properties of the plastic film proved its deformation upon exposure to heat,” explained researcher Anuja Joseph.
What could be the effect of long-term exposure to such microplastics?
Prof. Sudha Goel expressed concern over the bioaccumulation of microplastics in human and animal bodies.
“These microplastics can further act as carriers for contaminants like ions, toxic heavy metals and organic compounds which are similarly hydrophobic in nature thus allowing them to conveniently cross over to the animal kingdom. When ingested, the health implications could be serious,” she opined.
While the research to study the health impact of microplastics is relatively limited, researchers are assertive about adverse effects from both the environmental and health point of view. Such materials have been repeatedly linked with child growth and organ development, reproduction issues, disruption of hormones, obesity etc. At a spring conference at the Rutgers Center for Urban Environmental Sustainability, a research group presented the possibility of passing microplastics from the mother’s body to even the fetus.
“These contaminants can bioaccumulate in organisms leading to health issues like the disruption of the endocrine system, reproductive defects, cancer, neurological disorders and other effects. There could be further health challenges such as the impact on the sense organs, immune dysfunction or even cancer. That remains for domain experts to confirm while we can foresee the environmental mayhem these particles are going to cause if gone unchecked,” stated Prof. Goel.
Several states in India have been mulling over restricting the use of paper cups but feasible alternatives are not yet on deck. Referring to the situation, Director, Prof. Virendra K Tewari called for careful consideration before the promotion of replacements for bio-hazardous products and environmental pollutants. He said,
“We have been quick to replace plastics cups and glasses with disposable paper cups. While the need was crucial we have to find eco-friendly products. India has traditionally been a country promoting sustainable lifestyle and may be it is time that we look into our roots for corrective measures.”
He wondered if earthen products can meet the consumer demand for disposable plastic and paper cups.
“Atmanirbhar Bharat has to be in our thinking before we adopt it in our lifestyle and the country’s economy and everything we do should have a reflection of that thought process and thereby in our consumption behaviour,” he added.
Cite this paper: Ranjan VP, Joseph A and S Goel [2020] Microplastics and other harmful substances released from disposable paper cups into hot liquids, Jour. of Hazardous Materials, 404 (124118): 1-12. https://doi.org/10.1016/j.jhazmat.2020.124118
The International Conference on Advances in Polymer Science and Rubber Technology (APSRT) at IIT Kharagpur, organized by the Rubber Technology Centre from September 24-27, discussed what should be the future agenda for the world threatened by Climate Change. Plastics naturally figured prominently in the conference that mulled over how polymer science and the rubber industry had to focus intensively on driving innovation within the broad sustainability framework through waste prevention, re-use, repair, remanufacture and recycling. Prof. Thomas Kurian of the Cochin University of Science and Technology, for example, explained chemical recycling of PET bottles by a route based in aminolysis.
The conference not only brought together distinguished scientists, faculty members and technologists from the academia and industry the world over, but also students from various parts of the country. Among them were two from the Guru Nanak Institute of Pharmaceutical Science and Technology. Both took part in the poster exhibition at the conference.
At a time when the entire world is debating over how to get rid of plastics, the poster of Amandeep Kaur, one of the students, proclaimed, “Plastic is a unique and valuable material with many beneficial functions – it’s affordable, lightweight, transparent, flexible, durable and resistant to water.”
Her poster, however, did not deny the devastation plastics were causing. “Synthetic plastic is polluting our lands, oceans, and have negative impact on wildlife and human health as well” – Amandeep’s poster said.
The answer? Bioplastic, which is a biodegradable type of polymer. Both the postgraduate students – Amandeep Kaur and Suparna Ghosh – have been working in this field since their graduation. “The downside of traditional plastic is its production from non-renewable and fossil sources of petrochemicals such as Polystyrene, Polyvinyl chloride, nylon and Polyethylene,” explained Amandeep. But bioplastics are made from vegetable fats and oils, corn starch, straw, woodchips, sawdust, recycled food waste, etc, and are therefore biodegradable.
Amandeep has been working on the production of bioplastic from starch extracted from jackfruit and date seeds. She has used additives such as Chitosan, a naturally occurring linear polysaccharide compound, as an amplifier, as well as other additives to increase the transparency and plasticity property of her product.
At the conference she mainly attended the biochemistry sessions. An excited Amandeep said, “I got many new ideas which I can incorporate in my further studies. I have used starch as my basic component, but there is also cellulose I realized. Again, I have used Chitosan as an amplifier, but I learnt that I can also try resilin, which could be more effective and beneficial.”
Her friend from the same institute, Suparna Ghosh, has been working on bioplastics as well. Her poster demonstrated a simple format of producing bioplastic from potatoes, i.e. starch. The poster said, “To produce PLA (polylactic acid) from gelatinized potato with the help of lactic acid bacteria. To produce PSP from potato starch without any microbial culture”.
“Bioplastics have an extensive range of applications in the field of nanotechnology and membrane applications such as wound covering and in the sector of sanitary items and cosmetics. They can also be used in biomedical field for implants, tissue engineering, dermatological treatments and drug delivery,” said Amandeep.
The two students, who were visiting IIT Kharagpur for the first time, were thankful for the exposure the APSRT conference had given them. “The campus is beautiful and I thank the organizers for the exposure to new research that is going on, all of which are going to help us tremendously,” said Suparna. IIT Kharagpur has also been working on the recycling of polymers in order to produce oil and value added products.
At a time Greta Thunberg was creating a storm at the United Nations General Assembly with her speech, condemning world leaders for betraying the young, for failing to live up to their responsibility, it felt great to meet these two young girls from Kolkata. They were taking charge of their own future, and that of the world, with their scientific innovation. That is the spirit IIT Kharapgur inculcates in its students. That is the spirit it stands by.
About 30 students at IIT KGP have taken up the task of reducing single-use plastic usage in the campus. The students are in the process of forming a students’ society which among other environmental issues will extensively work towards creating social awareness in collecting and disposing of plastic waste including e-waste.
The students have led by example not using single-use plastic for over 4 months and inspiring other students in the campus to follow the feat. The group has also performed street plays in the campus market as part of the awareness campaign. Over 500 students have shown their interest in joining this society and take up the cause. The newly formed society named “Vision Prabaho”, would be undertaking projects to come up with innovative ways of organic, inorganic and electronic waste disposal.
“Segregation of waste is one issue and another is disposing of off the waste, reusing it. We hope these brilliant young minds would be able to come up with some innovations for urban Indians who are creating massive plastic waste which is causing problem for both urban and rural ecosystems,” said Barnali Chakrabarti, an environmental evangelist and the first lady of the campus.
The Prime Minister of India has been making extensive efforts to ‘Beat Plastic Pollution’– including an ambitious pledge to eliminate all single-use plastic in the country by 2022, which has been recognized by the United Nations. The initiative of Vision Prabaho by IIT KGP students follow this national mission of India.
“We hold a great responsibility to actively participate in dealing with the major environmental issues like the irresponsible use of plastics, waste and resource management, conservation of water body, preserving bio-diversity and reducing carbon footprint in and around the campus. Many of us emphasize human-induced environmental changes in recent years. We wanted to apply our own understanding to spread awareness and make changes on the campus. To us “Vision Prabaho” is an IDEA that should remain, even after we leave this beautiful campus,” opined the founding members, Biswarup, Pragnaditya, Sirsendu and Sudeshna, research scholars at IIT KGP.
The group will be working on increasing green cover and personal care for trees. Under the ‘You Plant, You Care’ campaign students are being encouraged to plant trees and nurture them which will carry their legacy even after they graduate. In a recently held photography competition on campus flora, the winners were awarded potted plants by Mrs. Chakrabarti who inspired them to care for the plants and conceived the campaign.
“There are about 30 students’ societies in the campus at present who are engaged in socio-cultural, sports, co-curricular, activities. “Vision Prabaho”, however, will be a unique society, not just in IIT KGP, but across all IITs, considering the fact that our campus is a mini-township and is witnessing challenges quite similar to urban areas though at a smaller scale though fortunately, we have a huge cover of greenery,” said Prof. William Mohanty, President, Technology Students’ Gymkhana at IIT KGP.