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Papers by pankaj pathak

Journal of Modern Agriculture and Biotechnology

Objective: Bioplastic is synthesized from organic substances and is biodegradable in nature. It c... more Objective: Bioplastic is synthesized from organic substances and is biodegradable in nature. It can solve the environmental problems associated with petroplastic and secure the future through prominent research efforts and growing environmental concerns. Though, in India, bioplastics are still in their infancy. Methods: It is currently facing various challenges such as strength, feasibility, and cost of synthesis. Moreover, markets are less aware of the concept and potentiality of bioplastics. In this study, bioplastics were prepared using household solid waste by extracting starch from potato and banana peels and further adding plasticisers. Results: The water-holding capacity and tensile strength of the synthesized plastic are 0.7wt% and 23.17MPa, respectively, which are comparable to commercially available plastic. Conclusion: This study describes the synthesis of bio-degradable plastic using vegetable waste and has significant applications in mulch farming.

Radionuclides and Heavy Metals in the Environment

The use of general descriptive names, registered names, trademarks, service marks, etc. in this p... more The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use.

The Handbook of Environmental Chemistry, 2020

Coal, oil, and natural gas are major conventional energy sources in the world but limited in amou... more Coal, oil, and natural gas are major conventional energy sources in the world but limited in amount. However, these sources create several environmental and health impacts during energy extraction processes. Coal mining and exploration, transportation, energy/electricity generation processes cause negative environmental externalities. Notably, electricity generation from coal alone emits approximately 60% of the global CO2, which has been projected as 36.4 GtCO2 in 2016. This scenario would be more challenging for developing nations to balance the increasing economic and industrial growth along with climate change issue. Therefore, alternative energy resources are recommended for the sustainable modern society to fulfill global energy demand with minimum environmental impacts.

Advanced Technology for the Conversion of Waste Into Fuels and Chemicals, 2021

Abstract Automobiles production is increasing at a faster rate due to rapid globalization and ind... more Abstract Automobiles production is increasing at a faster rate due to rapid globalization and industrialization. However, after the end of life of automobiles, huge amounts of waste is generated. One of the wastes is used tires. Worldwide, ∼1 billion tonnes of used tires are generated as a waste every year. However, the processing of the waste tires is extremely challenging due to their complex structure and varied composition. Therefore, either it has been directly thrown or burned on landfill. Thus, inadequate management of used (waste) tires causes adverse impact to the environment and social life. Hence, formal processing of waste tires needs extensive research in front of the scientific community. In this regard, gasification and pyrolysis techniques are being used to vaporize the waste tires into fuel and energy. This chapter describes the environmental impacts associated with waste tires if it is not processed properly and energetic valorization of waste tires into fuel and energy.

Handbook of Electronic Waste Management, 2020

Abstract An efficient management of E-waste is rendered indispensable and regarded as a major cha... more Abstract An efficient management of E-waste is rendered indispensable and regarded as a major challenge for today’s society. Greater contributory developed countries have established their policies on it and control their interests via either way of binding the legislation, paying to poor countries, and transferring used items in the name of bridging the techno-gap to underdeveloped countries. Such practices combined with in-house generation volume of E-waste in developing countries possess serious challenges to them. The major challenges they are facing either due to lack of or inadequate to handle the E-waste management practices. Most of the developing countries are still struggling for specific policy direction on E-waste, while one of the fastest growing economy and a large producer of E-waste countries, China and India could have finalized their legislation in very recent times; the implementation results are yet to have come. In this chapter, the policy constraints of developing countries for the effective management of E-waste have been analyzed with some particular examples. For this, the current practices, policy comparison between the developed and developing countries, and recommendations for a circular economy to the sustainable E-waste management in developing countries have been included.

Handbook of Environmental Materials Management, 2018

Environmental Science and Pollution Research, 2017

In the present study, changes occurring in sorption characteristics of a representative bentonite... more In the present study, changes occurring in sorption characteristics of a representative bentonite (WIn-BT) exposed to SrCl 2 (0.001-0.1 M) under the pH range of 1-13 were investigated. Such interaction revealed a significant variation in surface charge density and binding energy of ions with respect to bentonite, and alteration in their physicochemical properties viz., specific surface area, cation exchange capacity, thermal and mechanical behaviour were observed. The distribution coefficients (k d) calculated for sorption onto virgin (UCBT) and contaminated bentonite (CBT) indicated a greater influence of mineralogical changes occurred with variance of pH and strontium concentration. Notably, the sorption mechanism clearly elucidates the effect of structural negative charge and existence of anionic metal species onto CBT, and depicted the reason behind significant k d values at highly acidic and alkaline pH. The maximum k d of UCBT and CBT (0.001M SrCl2) were 8.99 and 2.92 L/kg, respectively, at the soil pH 8.5; whereas it was 2.37 and 1.23 L/kg at pH 1 for the CBT (0.1M SrCl2) and CBT (0.01M SrCl2) , respectively. The findings of this study can be useful to identify the physicochemical parameters of candidate buffer material and sorption reversibility in waste repository.

Minerals

Incessant generation and mismanagement of industrial waste, resource scarcity, and environmental ... more Incessant generation and mismanagement of industrial waste, resource scarcity, and environmental degradation have created non-sustainability in human life. Though industrial wastes are hazardous or non-hazardous in nature based on their source, open dumping disposal is commonly done for both types of waste. The adversity associated with waste enhances the environmental and health impacts. However, this waste has the potential to recycle and minimize resource scarcity. The circular economy works on the concept of reuse, recycling, and recovery to convert waste into a resource. Thus, industrial waste can benefit the environment and economic growth to build industrial ecology. However, the opportunities and challenges associated with industrial ecology for the reuse and recycling of waste have to be identified and preserved. Therefore, this study has identified challenges associated with waste, analyzed their impact, and industrial regulations, prioritized their criticality, and develo...

Electronic Waste Management and Treatment Technology

Abstract The waste derived from electrical and electronic equipment (i.e., E-waste) causes severe... more Abstract The waste derived from electrical and electronic equipment (i.e., E-waste) causes severe issues for the geo-environment. The heterogeneity and complexity of E-waste, containing lethal and toxic substances, are difficult to decompose and are classified as hazardous materials. High exposure of hazardous materials is harmful to human life. The improper management of E-waste with processing by the informal sector in nonscientific manner is making this scenario catastrophic. Additionally, illegal shifting by mislabelling E-waste from developed countries and exporting to developing countries makes it difficult to calculate the inventory and handling of the E-waste. Therefore, a sustainable environmental management of E-waste by policies and governing regulations from its collection to recycling are necessary. These measures of E-waste management should increase the advance recycling practices by the formal sector and decrease the amount of waste contamination to the environment that is endangering human health and whole ecosystem.

JOM

Hydrometallurgical extraction of strategic metals from exhausted Li-ion batteries has been explor... more Hydrometallurgical extraction of strategic metals from exhausted Li-ion batteries has been explored using sequential application of biodegradable oxalic acid and sulfuric acid solutions. Following L25 orthogonal design of experiment (DoE), optimized extraction of > 99% Li and Cu with organic acid was achieved using a H2C2O4 concentration of 0.25 mol L−1, solid–liquid ratio of 10%, H2O2 at 0.5%, temperature of 80°C, and duration of 90 min. Subsequently, leaching of the residual mass in mineral acid yielded 99% efficiency of Ni, Co, and Mn at the optimal condition of H2SO4 concentration of 3.0 mol L−1, solid–liquid ratio of 6%, H2O2 at 2%, temperature of 60°C, and duration of 120 min. Fitting of the kinetic data using a logarithmic rate law revealed that, except for Cu that followed an intermediate-controlled mechanism with Ea = 27.6 kJ mol–1, all the other metals exhibited a diffusion-controlled mechanism with Ea < 12 kJ mol–1. Not only does this study demonstrate selectivity that will be beneficial to downstream processing, but the use of DoE also makes it applicable industrially.

The Handbook of Environmental Chemistry

This chapter provides an outline of alkaline earth metals’ contamination caused by the industrial... more This chapter provides an outline of alkaline earth metals’ contamination caused by the industrial and nuclear pollution. The assessment has been done for quantifying sources (viz. natural and anthropogenic) of the alkaline earth metals along with describing the physicochemical characteristics of calcium, strontium, and barium. The isotopes of strontium, calcium, and barium are found to have significant impact not only onto the human health but also the geoenvironment. In this view, estimation of risk assessment caused by these metals is mandatory and also described in this chapter. Notably, calcium is one of the most significant elements in human body in the form of bone skeleton. In contrast, strontium and barium are non-essential elements for human beings; however, due to their similar characteristics with calcium, they get managed to enter within the human body via accumulation onto the tissues and bones. Therefore, the quantification of strontium and barium is imperative that can be done by measuring ratios with respect to calcium (as, Ba:Ca and Sr:Ca).

Geomaterials have peculiar physical, chemical and mineralogical properties. These properties infl... more Geomaterials have peculiar physical, chemical and mineralogical properties. These properties influence their interaction with the contaminants to a great extent. This interaction can be quantified by employing a parameter, “Distribution Coefficient”, kd, which plays an important role for determining sorption and desorption characteristics of a contaminant when it interacts with geomaterials. As such, its determination becomes mandatory for understanding and quantifying the mechanism(s) by which geomaterials get contaminated. With this in view, kd parameter for a solution of model contaminant when it interacts with a geomaterial, was determined by conducting laboratory studies. This paper presents details of such studies and a commentary on the guidelines for determining the kd parameter, and its importance and applications in various geoenvironmental engineering problems.

There is a dire need to replace the chemical buffers that regulate the redox environment in singl... more There is a dire need to replace the chemical buffers that regulate the redox environment in single-stage anaerobic digestion (AD) of food waste (FW). Hence, the applicability of grass clippings (GC) as an eco-friendly buffering agent and biomass during the anaerobic co-digestion of FW was explored. A focus was primarily given on the effects of GC on the redox environment and acidogenesis. Concomitantly the production of volatile fatty acids, hydrogen and methane in mesophilic conditions was monitored. Organic load and substrate to inoculum ratio were kept constant in all the experiments, and no chemical buffer was used. The results revealed that GC regulated the redox environment by inhibiting rapid pH drop in the digester with 10 % GC. The addition of 2, 4, and 6 % GC promoted acidogenesis with increased production of acetic and butyric acids; whereas, 8 and 10 % GC promoted solventogenesis with ethyl alcohol production. Hydrogen generation from the experiments with GC was in the r...

Journal of Environmental Management

Open dumping is a common practice for MSW disposal in most of the Indian cities, apart from the m... more Open dumping is a common practice for MSW disposal in most of the Indian cities, apart from the metro-cities. This practice poses significant environmental and health risks due to toxic and greenhouse gases (GHGs) emission through direct combustion and/or decay of wastes. Therefore, integrated solid waste management (ISWM) using different methods viz., incineration, composting, anaerobic digestions, refuse derived fuel, material recovery facility and sanitary landfilling, is much needed. Accordingly, three waste management case scenarios were studied for year 2001-2051 by keeping weightage of sustainable development goals 2030 of India. Case I depicts Indian present scenario of waste management where 164-735 tonnes/year of wastes would be generated for year 2001-2051. Further, 60% of waste can be treated in case II that help in reducing the land requirement up to 40% from estimated conditions of 2031 i.e., 83.8 × 107 m3. The case III is most ideal waste management condition for year 2031 to reduce 80% waste hence landfill requirement would minimize up to 16.76 × 107 m3 where population is at controlled conditions. This article concludes the formal handling and treatment of ISWM would minimize the landfilling, where LCA can be an antidote to achieve sustainable development goals.

Exposure and Health

The present study quantifies the personal exposure to air pollutants (i.e., PM 2.5 , PM 10 , CO 2... more The present study quantifies the personal exposure to air pollutants (i.e., PM 2.5 , PM 10 , CO 2 , and CO) and its bound chemical constituents during bonfire activities occurring in rural area of Gujarat, India. The study was performed during the late 2017 and early 2018 winter season, when bonfires are a very common practice. Three major sites, viz., University Reception Area (URA), Workshop Area (WSA), and Hostel Wing-A (HWA) were delineated to reveal discrete patches of personal exposure. Particulate matters, gaseous pollutants, and associated ionic constitutes were analyzed by an air quality monitor and ion chromatography. The concentration profile of PM 2.5 , PM 10 , and CO were found in the range between 81–206, 188–282, and 2.8–5.8 µgm −3 , respectively, at the study area which are more than the permissible limit. The major ions such as Na + , K + , Ca 2+ Mg 2+ , NH 4 + , Cl − , Br − , NO 2− , NO 3− , PO 4 2− , and SO 4 2− were obtained on particulate matter. Based on this observation it is concluded that if personal exposure to these pollutants increases, then metabolic activities may change and lead to severe diseases, viz., asthma, rhinitis, tuberculosis. It is a grave concern for the WHO to improve the human health and eradicate the communal diseases under sustainable development goals. Henceforth, it is mandatory to understand the variations of air pollutants at workplace and the associated exposure to individuals.

Journal of Hazardous, Toxic, and Radioactive Waste, 2015

AbstractIn nature, when contaminants come in contact with geomaterials (i.e., soil, minerals and ... more AbstractIn nature, when contaminants come in contact with geomaterials (i.e., soil, minerals and rock mass), geomaterial-contaminant interaction occurs, which can be quantified, mathematically, by employing distribution or partitioning coefficient, kd. This interaction is strongly influenced by the geomaterial and contaminant specific parameters. Among these parameters, the concentration and nature of the contaminant (in solution form) is one of the most important parameters that control this interaction critically. However, it is the authors’ hypothesis that another parameter, electrical conductivity of the geomaterial-contaminant system (GCS), which is dependent on type of the geomaterial (i.e., its chemical and mineralogical properties) and contaminant(s) could be used for a precise understanding of geomaterial-contaminant interaction. Hence, in order to investigate the effect of the concentration and electrical conductivity of the GCS on this interaction, geomaterials and contaminants of different typ...

Journal of Environmental Engineering

AbstractThe sorption isotherms, kinetics, and thermodynamics of contaminants, e.g., strontium, le... more AbstractThe sorption isotherms, kinetics, and thermodynamics of contaminants, e.g., strontium, lead, and uranium, for four different Indian soils (named S1, S2, S3, and S4) were investigated. Batch...

Environmental Engineering Research

In accordance with the Paris Climate Agreement (COP21) and Sustainable Development Goals (SDGs), ... more In accordance with the Paris Climate Agreement (COP21) and Sustainable Development Goals (SDGs), India is greatly focused on deployment of renewable energy (RE) for supplementing the energy requirements of the country. The present article assesses the validity of the promises offered by RE technologies in India and its necessary action to understand the gap between setting goals and the ground situation, which can also show a pathway to other developing countries. Therefore, the long-term projection perspectives on RE growth have been made using the India Energy Security Scenario-2047. In order to achieve the set target for emissions reduction of greenhouse gases (GHGs) i.e., 1209 MT CO2e in support of SDGs to the 2005 level by 2030, three renewable growth scenarios have been tested for transitioning the Indian energy system. Accordingly, the regression analysis reveals that the most desirable growth scenario will require a steady rise of RE contribution in the overall energy mix of...