There is a growing demand for decentralised systems that use renewable energy to extend the shelf life of agricultural commodities. Solar Air Heating systems (SAHs) are effective and environmentally friendly systems used to preserve agricultural produce by lowering the moisture content. Assistant Professor Dr Karthik Rajendran and his Post-Doctoral Scholar Dr VS Vigneswaran from the Department of Environmental Science have published their paper “Augmented v-corrugated absorber plate using shot-blasting for solar air heater – Energy, Exergy, Economic, and Environmental (4E) analysis” in the Q1 journal “Process Safety and Environmental Protection” having an Impact Factor of 7.9. The paper was published in collaboration with D. Sung Chul Kim, Shandong University, China.

South Asia is home to the majority of the world’s hungry people. Among 116 nations, India, the second-most populated nation in the world, is ranked 101st in the global hunger index. There is cause for concern given that India loses over 67 million tonnes of food annually, which is equivalent to about Rs. 92,000 crore. In 2016, the Indian Council of Agricultural Research estimated that during harvest, post-harvest, processing, and storage, about 4.3-6.1% of pulses, 3.9-6% of grains, 2.8-10.1% of oilseeds, 6.9-13% of vegetables, and 5.8-18.1% of fruits were lost. 16% of fruits and vegetables as well as 10% of oilseeds, pulses, and cereals were lost in India due to inadequate access to storage facilities.

Each year, these losses increase in India. In order to reduce food wastage after harvest and the amount of people going hungry in India, technologies must be developed to extend the shelf life of agricultural produce. The utilisation of land, water, energy, and the release of greenhouse gases into the atmosphere can all be decreased by reducing postharvest loss. It is necessary to develop a decentralised system that uses renewable energy to extend the shelf life of agricultural products. Given that the majority of India has abundant solar energy resources, solar crop dryers based on solar air heaters (SAH) are a practical choice for conserving agricultural output by lowering its moisture content. These technologies are appealing because they are affordable and sustainable.

The performance of SAH is determined by the absorber plate. Thus, the SAH was modified with a v-corrugated absorber plate with a shot-blasted surface, and the SAH performance was investigated experimentally. Performance parameters including the energy and exergy efficiency of the collector were determined and compared with those of the conventional SAH. The study inferred that SAH optimisation will make way for the maximisation of its efficiency.

Abstract of the Research

Need for increasing the shelf life of agricultural produce using renewable energy-based A decentralized system are significantly increasing. The solar air heating systems (SAHs) are efficient and environment friendly systems which are used for preserving agricultural produce through the reduction of moisture content. However, these systems had poor thermal efficiency and the way for increasing the efficiency are much need in the present era. This article presents the energy, exergy, and economic analysis of a modified solar air heater system (SAH). The proposed (modified) SAH has a V-corrugation absorber plate; the inner surface was modified using shot-blasting technology. This is the first study to experimentally investigate a modified SAH and compare the results with those of a conventional SAH. Additionally, an environmental and sustainability assessment of the SAH is presented. The SAH performance was tested at airflow rates ranging from 0.01 to 0.02 kg. sec.

Read the full paper here.

The Department of Environmental Science is glad to announce that Assistant Professor Dr Pankaj Pathak and her PhD Scholar Mr Gopa Nandikesh have published an article titled “Occurrence, environmental risks and biological remediation mechanisms of Triclosan in wastewaters: Challenges and perspectives” in the Journal of Water Process Engineering having an Impact Factor 7.34. The paper was published in collaboration with Dr Lakhveer Singh, Sardar Patel University, Himachal Pradesh.

The paper makes a comprehensive understanding of the disadvantages and consequences associated with the excessive use of Triclosan (TCS), an anti-microbial agent widely used in pharmaceutical and personal care products (PPCPs). The article also suggests various ways to achieve the bioremediation of Triclosan using microbial degraders and the different challenges associated with such practices.

The extensive use of TCS in PPCPs has increased over the past few decades, and its sizeable production and consumption are causing adverse effects on the environment and humans. TCS has been made into the list of emerging micropollutants (EMPs) due to its omnipresence in water resources and even in biological samples such as urine and breast milk. Therefore, it is imperative not only to understand the current status of TCS pollution but their occurrence, exposure routes, and environmental risks to identify remediation technologies for mitigating TCS.

Their research targets to provide cumulative data on the abundance of emerging TCS in water resources and its associated health burdens simultaneously. It is identified that TCS remediation can be achieved through advanced physical and chemical methods such as enzyme oxidation and ozonation. However, there are drawbacks such as high energy consumption and the formation of toxic by-products.

The article endeavours to provide an in-depth understanding of the biological remediation of TCS by microbial degraders as well as its superiority over other remediation techniques. Insights into the various microbial communities such as bacteria, algae, and fungi and their unique bioremediation mechanisms are comprehensively summarised. Moreover, challenges associated with existing bioremediation methods and future perspectives are also discussed in the present work.

Tropical forests are the breathing lungs of the world that work as a collective to stabilise climate by absorbing vast amounts of carbon dioxide. Covering over 12% of Earth’s total land surface. It functions as a harbour for evolution and supplying prerequisite rainfall for healthy vegetation. Recent global climate changes have catalysed drastic effects on the tropical forests and the healthy functioning of the same. A critical understanding of the present state of forest ecosystems is crucial for undertaking necessary measures to prevent further degradation.

Recently, the project entitled Assessment and modelling of carbon and nitrogen dynamics in tropical forests of Eastern Ghats, Andhra Pradesh in response to climate change, has been sanctioned to Dr Javid Ahmad D, Assistant Professor, Department of Environmental Science by DST – SERB (Science and Engineering Research Board), Govt of India, with a total outlay of Rs. 28.54 lakhs. Dr Javid Ahmad D is the principal investigator of the project.

A complete dataset on long-term dynamics in vegetation, the C and N generated for different tropical forest types in the Eastern Ghats landscape would serve as a baseline data for forest managers and policy-makers. The project aims to gain insight on the response of these tropical forests to changing global climate in relation to multiple factors (elevated CO2, increased temperatures and altered precipitation).

Solid waste is primarily an overlook source of Microplastics that contribute to a delirious amount of pollution to the environment. Thus, a clear understanding of the occurrence and degradation pathways of solid waste microplastics is critical to develop exhaustive control strategies. Dr Deblina Dutta, Assistant Professor, Department of Environmental Science, has published a paper titled, “An insight on sampling, identification, quantification and characteristics of microplastics in solid wastes” in the Q1 journal Trends in Environmental Analytical Chemistry, having an Impact Factor of 13.62.

Abstract of the Research

Microplastics (MPs) have attracted wide attention worldwide as a remarkable pollutant. While MPs spread throughout several complex environmental matrices, various experiments have been preliminarily concentrated on aquatic ecosystems. Terrestrial sources namely solid waste-origin have remained unexplored, although they contribute largely to the origin of aquatic microplastics. Simultaneously, terrestrial systems under human activity, like healthcare units, are likely to be polluted by various plastic ingredients. Solid waste MPs sources primarily include sanitary landfilling, food waste, wastewater treatment end-product (sludge), tire wear, textile washing and paint failure. These microplastics cause adverse impacts on the ecosystem, environment, and health. Accordingly, the present study addressed solid waste MPs’ occurrence and sources, identification, quantification, characterisation, fate, and degradation pathways for developing comprehensive management strategies following the principles of a circular economy.

In particular, this paper critically demonstrated solid waste MPs sources, solid waste MPs sampling followed by identification and quantification by adopting combined chemical (e.g., spectroscopy viz., Fourier transform infrared (FTIR) spectroscopy, and Raman spectroscopy), physical (e.g., microscopies such as transmission or scanning electronic microscopy, TEM or SEM) and thermal analyses. Additionally, the strengths and limitations of each analytical technique are discussed critically with practical aspects. Further, national and international regulations or laws and their subsequent relevance to solid waste MPs management with future challenges are critically discussed. Finally, the outcomes of the review paper will be valuable to different stakeholders for effective policy implementation.

Explanation of the Research in Layperson’s Terms

The published paper deals with microplastics (5 mm to 0.1 μm in size) present ubiquitously in the natural environment including rivers, lakes, estuaries, atmosphere, oceans, soil/sediments, landfilling sites, and wastewater treatment plants. However, microplastics are also present in solid waste and studies related to their identification, characterisation, and quantification are very scarce. Therefore, to know more about microplastics and understand the sources of microplastics in solid waste, the extraction procedures, the identification, characterisation, and quantification techniques, and finally the advantages and disadvantages of each of the processes involved in the identification, characterization, and quantification techniques of microplastics, this study has been carried out.

Practical Implementation/ Social Implications of the Research

Waste-assisted plastic pollution is a major global concern with socio-economic, ecological, and health effects. The present study will make society understand the source of microplastics in solid waste along with its extraction procedures, identification, characterisation, and quantification techniques. If society is aware of the adverse effects of microplastics, then only one can think to protect the environment and human health.

Collaborations

The research has been carried out in collaboration with the University of Burdwan, the University of North Bengal, and CSIR-NEERI, Nagpur.

It is now widely recognised that microplastic pollution poses a serious threat to the environment on a global scale. Having originated from a diverse source, it has persisted in various ecosystems, thereby entering the trophic chain. It has contributed to microplastic pollution in the environment, e-waste being a major source of it. Hence, along with metal recovery from e-waste, regulating microplastic pollution is a growing interest. At this juncture, Dr Dutta’s future research is directed towards resource recovery processes, regulating microplastic pollution, risk assessment, life cycle assessment, and techno-economics analysis.