Journal of the Indian Institute of Science最新文献

Plastic waste is a growing concern globally on account of the increasing use of plastic worldwide, compounded by single-use applications, poor waste collection and management practices, and its consequent leakage into the environment. In addition, plastics are derived from non-renewable fossil resources, and their growing demand is also partly responsible for greenhouse gas emissions and climate change. The aim of this paper is to explore the potential of plastic waste as a material resource, and thermocatalytic pyrolysis as a recycling process, to produce aliphatic and aromatic hydrocarbons, which are important chemical intermediates for various industries. We show that plastic pyrolysis can achieve a high yield of liquid hydrocarbons (~ 80%) with a suitable distribution of aliphatic and aromatic compounds, by using different pyrolysis conditions and a catalyst. Specifically, this paper demonstrates the possibility of deriving two key classes of hydrocarbons, i.e., aliphatic (C10–C20 hydrocarbons) and aromatic hydrocarbons (xylene, toluene and benzene derivatives) with a yield of ~ 80% liquid hydrocarbons via catalytic pyrolysis. We also briefly discuss the challenges and opportunities, and the environmental and economic implications.

Biomass as an energy source for the millions of under-privileged families in rural and semi-urban settings in India and over a large part of the World remains an ever-present necessity that remains acknowledged only in scholarly publications. Modern solutions for the combustion applications even when available are allowed to remain without adoption. This has resulted in attempts to deal with commercial applications as well as larger scale drying of perishables with novel techniques for fast drying while preserving the quality of dried products as approaches to make waste biomass use valuable to the society. This article provides a very brief history of improved cook stove development and dissemination both of fixed and portable forms with further evolution of fan-based technologies—batch and continuous combustion modes aimed at higher combustion efficiency and lower emissions. The role of biomass quality that has remained unaddressed all along will be discussed with solution strategy for production and commercial supply of solid fuels. That biomass fraction of urban solid waste is largely a renewable biomass source and can be treated to obtain quality biomass-based fuels for societal use is discussed in some detail and is argued to be a continuous source of supply of fuels to meet the energy demands.

Wetlands (lakes, tanks, ponds, etc.), transitional lands linking hydrologically the terrestrial ecosystem with aquatic ecosystems with biophysical interactions, are the most productive and diverse ecosystems and provide numerous ecological, economic, and social benefits for human well-being. These vital ecosystems sustain ecological processes to provide services such as nutrient cycling, water purification, reducing pollution, carbon sequestration, groundwater recharge, provision of fish, fodder, fuel, and water, flood reduction, erosion control, aquatic biota habitats, education opportunities, aesthetics, and recreation. However, due to globalization, these fragile ecosystems are vulnerable to unplanned developmental activities and rapid urbanization, leading to large-scale land cover changes and hydrologic regimes. The sustained inflow of untreated wastewater (from the industrial and domestic sectors) into wetlands has altered the chemical integrity, which necessitates inventorying, mapping, and regular wetland monitoring to evolve conservation strategies. Integrating spatial and non-spatial data, analysis, and visualization with decision models through decision support systems enables informed decisions. In this context, the Bangalore Lake Information System (BLIS) is designed with information on water quality, biodiversity (microalgae, zooplankton, ichthyofauna, macrophytes, and birds), threats (encroachments, inflow of untreated sewage, etc.) and ecosystem services of lakes in Bangalore, Karnataka State, India. Rapid large-scale land use changes have resulted in an alteration in the hydrologic regime, the loss of habitats, and the disappearance of native species. BLIS empowers decision-making through knowledge of lake distribution in terms of the physical, chemical, and biological aspects and the value of ecosystem services, which is crucial for evolving strategies for prudent management of water bodies in Greater Bangalore.

The paper focuses on review of developments in low carbon building technologies since the inception of ASTRA/CST. Five decades of R&D and dissemination of alternative building technologies has been traced in three phases. The narrative highligts many building technologies developed, R&D work through doctoral programmes and sponsored research, capacity building and design of special courses. The impact of the low-C technologies on the construction industry, emission reduction and public investment on these technologies have been highlighted. The ASTRA/CST work ultimately resulted in over 4 million tonnes of carbon emission reductions. Apart from training many building professionals and the work provinded innovative topics for the doctoral reseach programmes at Indian Institute of Science.

Dumpsite remediation has become a crucial aspect of sustainable waste management. This study reviews the current state of knowledge on dumpsite remediation, identifying key gaps in the literature. It explores site investigation, characterization of dumpsites, and remediation techniques, with a focus on dumpsite mining and rehabilitation measures. In the context of dumpsite mining, the study examines the potential recoverable fractions, challenges in recyclability and processing, and the economic aspects of mining operations. For rehabilitation, it discusses the importance of slope stabilization, leachate and gas management, and long-term monitoring strategies. Given the lack of specific criteria for selecting appropriate remediation methods based on site requirements, the study proposes criteria for choosing sustainable approaches. Additionally, case studies are reviewed to demonstrate the successful application of dumpsite remediation for environmental protection and containment, as well as the potential of mining to generate value-added products within a circular economy perspective. However, challenges observed in the case studies, such as heterogeneous waste composition, technological limitations, and economic viability, present significant barriers. The study suggests that overcoming these challenges requires legislative support, infrastructure development, and stakeholder collaboration. The paper concludes with recommendations for advancing circular economy solutions, emphasizing the need for integrated waste management, innovative technologies, and cooperative efforts to achieve sustainable waste management.

Source-separation of urine (urine diversion) is a well-established concept with proven sanitation benefits, promoting sustainable (waste)water management and circular economy, gaining increased attention worldwide. Although urine comprises only 1% in municipal wastewater by volume, it mostly accounts for nutrient loads in wastewater (85–90% of N, 50–80% of P, and 80–90% of K). Source-separation of urine: improves sanitation, conserves water, can partly substitute synthetic fertilizers in agriculture, and reduces energy and space requirements at wastewater treatment plants. This paper reviews the developments in source separation and valorization of urine, its benefits, methods for treatment, and challenges for implementation. Further, implications of source-separation of urine in Indian context (as an example of developing/emerging economy) is highlighted.

Graphical Abstract

Integrating resilience and sustainability into engineering projects from their inception is more crucial now than ever. Our world is grappling with environmental challenges and socio-economic uncertainties, heightened by risks such as climate change impacts, population growth, resource depletion, urban sprawl, and social injustice, among others. A unified framework capable of quantifying and integrating these aspects into engineering projects is essential to address these challenges effectively. Despite the importance, there is a scarcity of frameworks tailored for this purpose, while existing industry rating tools are often subjective and have limitations in integrating these concepts effectively. A general integrated sustainability and resilience assessment framework (named Tiered Quantitative Assessment of Life Cycle Sustainability and Resilience (TQUALICSR)) was developed at the University of Illinois Chicago to bridge this gap. However, the potential of such a framework has not been fully realized in past studies as they are confined to specific techniques, methods, and tools, limiting the applicability of the proposed framework for diverse engineering projects. The primary aim of the current study is to provide a comprehensive understanding of the proposed framework and offer alternative tool options for each stage of the assessment process. We begin with a thorough review of definitions of resilience and sustainability concepts, establishing functional definitions for broader use. The proposed general framework classifies the variables related to resilience and sustainability into quantitative (Tier 3), semi-quantitative (Tier 2), or qualitative (Tier 1) variables, providing flexibility based on data availability. The integrated assessment starts with a robust resilience assessment, incorporating elements such as functionality curves for technical resilience quantification and cascading environmental, social, and economic impacts as other necessary dimensions of resilience. Subsequently, resilient design alternatives resulting from the resilience assessment undergo a comprehensive sustainability assessment that considers all three triple bottom-line aspects of sustainability, using various tiers of variables and tools as available/suitable. The quantified variables then face the challenge of integration and decision-making as these variables often differ in units of measurement and magnitudes. To address this, we discuss various normalization techniques, weighing methodologies, and multi-criteria decision analysis (MCDA) tools, outlining their principles, procedures, advantages, and drawbacks. By delineating the phases of the proposed framework and presenting diverse tool options, engineers can select the most suitable techniques for their projects and perform an integrated quantification of resilience and sustainability.