Green Chemistry in Environmental Sustainability and Chemical Education

Xenobiotics are the chemicals, which are not found in nature and are said to be foreign substances in the atmosphere. These compounds are synthesized by human beings e.g. pesticides, that may be added in the soil to kill the harmful pests but in addition this, these pesticides also kill the beneficial microorganisms that are responsible for the fertility of soil. Moreover, these compounds can be accumulated in food chain and cause harm to the flora and fauna of such ecosystem. For the degradation of such xenobiotic compounds various physico-chemical and biological methods have been used but all these methods produce toxic by-products that are hazardous to the environment. Thus Bioremediation is a promising tool for the degradation of such compounds. In the present paper, we have emphasized on the remediation of xenobiotics by using microorganisms. Bacteria and Fungi play an important role in breaking down certain hazardous substances into simpler fragmented forms. Bacteria, which are used for bioremediation of xenobiotics includes aerobic, anaerobic, Methanotrophic, Methanogenic bacteria, Cyanobacteria and Sphingomonads. Pseudomonas species has been used for the degradation of several xenobiotic compounds. In addition to this, certain fungi such as Aspergillus, Rhizopus, Botrytis, Neurospora etc. have been used for the heavy metal biosorption. Hence we can say that fungi are one of the promising tools for the eco-friendly degradation of xenobiotic.

As the world approaches towards rapid industrialization and globalization, the efficient use of resources along with their conservation has become the mantra for the world to move on sustainable development path. While companies are involved in various activities to produce and trade goods and services to maximise their profit and increase shareholder’s wealth, they need to simultaneously focus on Environmental Management, Corporate Social Responsibility and Sustainability policy. The responsibility towards society and environment just no longer lies with the Public Sector and Government but also with the Private Sector. As per the Companies Act 2013, it has become compulsory for large companies to spend 2% of their net profits on Corporate Social Responsibility activities. Indian Companies which are actively working in this area include Mahindra and Mahindra, Tata Steel, Reliance Industries, Hero Motors, Infosys and Wipro to name a few. Various activities undertaken by companies for Environment Management under CSR include water conservation, tree plantation, developing green products, using renewable sources of energy and waste management. The paper aims to analyse the initiatives and steps taken by selected Indian Companies under CSR and Sustainability for Environmental Management and Protection. It also focuses on what areas of environment they have covered and the impact of these initiatives. This is done by analysing secondary sources of information. Also it provides suggestions on various other initiatives that can be taken and how these can be effectively implemented for better future of the country.

Copper and copper oxide nanoparticles (NPs) have been synthesized by electrochemical route using the Tri-Sodium Citrate 150 mM (TSC) as a capping and reducing agent. The synthesis has been done at 3.2 V, 311 K using copper rod as a working electrode and Platinum wire as a reference electrode. The electrochemical set up has been kept in air as well as under inert Nitrogen-purged conditions. The NPs have been characterized by using UV–visible absorption spectroscopy, Scanning electron microscopy (SEM), and powder X-ray diffraction (PXRD) techniques. This new kind of synthesis method shows the excellent stability compared with that of another chemical method of copper nanoparticles. These particles have been used in photocatalytic-oxidation of organic pollutants.

Carcinogenic properties of Chromium(VI) have been studied extensively and reported. The majority of the environmental releases of chromium are from industrial sources. Rhodamine B is a synthetic dye widely used as colourant in the manufacture of textiles and food stuffs. Rhodamine dyes present in drinking water could lead to subcutaneous tissue borne sarcoma which is highly carcinogenic. Other toxicities like reproductive and neurotoxicity have been investigated and proved. The work reported involves the removal of Cr(VI) as well as Rhodamine B dye using pine needles by the process of adsorption. The adsorption studies were performed by batch process and the detection done using UV–visible spectrophotometer at 540 nm for Cr(VI) and 554 nm for Rhodamine B. Various parameters like pH, concentration of adsorbent, mass of adsorbate, time of contact were optimized. The percentage efficiency for removal under optimized conditions, of Cr(VI) and Rhodamine B dye was up to 96 and 92% respectively. The adsorption studies were performed using Freundlich and Langmuir adsorption isotherms as well as the kinetic and thermodynamic parameters have also been determined. This technique can be effectively used for the detoxification of water by the removal of metal ions and dyes obtained from industries.

With recent impetus on building of smart cities, modern urban settlements and expansion of established settlements, solid waste management, sufficient energy supply, water pollution and water borne diseases have become an inseparable trouble. The need of the hour, thus, is an efficient and rapid remedy to these issues which is not only feasible but economically viable as well. Present study concentrates on how horticultural and commercial organic waste can be converted to pellets and after further processing can be utilised to combat water pollution and production of energy. Pellets are condensed product of above mentioned waste which is capable of utilizing these waste that is generated each day in tons. Pellets can be utilized directly as an alternate mode of fuel in certain areas. Analysis of pellets makes it clear that it’s a cleaner and greener substitute to coal. Pellets after combustion gives rise to biochar which finds wide application in water purification and hence is considered as a remedy to water pollution. Pellet biochar possesses certain specific architecture and molecular composition which varies with temperature, residual time, feedstock type and heat transfer rate. On gasification of pellets, syngas is produced which can be used for running engines as well as generating electricity.

Microbial diversity is the most fundamental component of any ecosystem on Earth. Microorganisms are the most abundant and diverse as they comprise the majority of soil biomass. Microbial community plays a crucial role in ecosystem functioning by controlling biogeochemical cycles of elements essential for life, such as carbon (C) and nitrogen (N). They have great potential in energy conversion and regeneration and will likely be an important component of ecosystem response to climate change. The global climate is changing drastically due to; 1-green house gasses such as CH₄-Methane, N₂O-Nitrous oxide, CO₂-Carbon dioxide, Chlorofluorocarbons (CFCs); 2-organic and inorganic pollutants such as heavy metals, ammonia, cyanide, volatile and halogenated compounds. All are released by different industries viz: textile, leather tanning, plastics, pharmaceuticals etc. More than 3.0 million metric tons of toxic chemicals from over 2,000 industries are annually released into the environment. More than 45,360 metric tons (100 million pounds) of toxic compounds are carcinogens. These contaminants not only increased water and agriculture land contamination but also cause various health-related problems. Most of the physio-chemical methods for detoxifying contaminated sites are expensive and release toxins. Therefore, use of Pollution-Eating Bacteria (PEB) viz; Acinetobacteria, Azospirillum, Bacillus, Proteobacteria, Pseudomonas and Serratia is preferred to improve contaminated sites. Unique soil microorganisms also produce beneficial enzymes which degrade pollutants without leaving any toxic intermediates. Various species of Bacillus, Flavobacterium, Paenibacillus, Pseudomonas, Rhodococcus and Serratia cause partial or complete degradation of harmful pesticides like morpholine, methyl parathion and benizimidazole compounds and have dynamic potential to increase crop yield. Microbes produce beneficial enzymes that solubilize highly insoluble nutrients locked up in soil viz: iron (FeIII) and phosphate complexes (Al, Ca and Fe phosphate). These Plant Growth Promoting Microorganisms (PGPMs) also enhance soil quality. Both biotic and abiotic stresses are responsible for the loss of >40% of agricultural production. Various culturable microbes work as an excellent bio-control agent to protect crops from nutrient stress and plant pathogens such as Aspergillus, Fusarium, Pythium, Phytophthora, Rhizoctonia and Sclerotium. Additionally, Acinetobacter, Arthrobacter, Bacillus, Marinobacter, Microbacterium, Panibacillus and Pseudomonas are used for bioremediation and bioaugmentation technology. The present review paper will help in better understanding of microbial ecology and its crucial role in the detoxification mechanism of polluted sites, and environmental stability.

The pesticides use is unavoidable to meet the food production demands of the ever-increasing population. However, these organo-chemicals and their naturally degraded products have tendencies to bio-accumulate and enter into food chain. The toxic nature of these harmful chemicals has become a serious threat to environment in general and to human health in particular. Significantly, high levels of organochlorine pesticides have found to be proliferated into various foodstuffs taken from different regions of India. Average intake of DDT is found to be 48 μg/g, which is quite high. The wide range health hazards and the ability of bioaccumulation of pesticides and their generated waste by-products necessitate the need to degrade these to safer products using suitable economically viable techniques. Mixed metal oxides (MMO) nanoparticles are potential versatile heterogeneous catalysts and may find use in the field of synthetic organic chemistry. The nanostructured binary mixed metal oxides of bivalent metal ion Mg²⁺ with Al³⁺ and Ce⁴⁺ have been synthesized by sol–gel methods with suitable modifications to increase surface area and to decrease size. The mixed metal oxides have been characterized by several spectroscopic and analytical techniques such as XRD, SEM, TEM. Thereafter the catalysis activity of the nanoparticles was tested on DDT degradation by gas chromatography. Results indicated that nanoparticles are efficient catalyst in remediation of DDT as 90% degradation was achieved in first 24 h.

Water effluents of various chemical laboratories are expected to consist of wide range of organic waste products whose removal is an arduous task and a serious concern with the objective of eradication of all the pollutants from laboratory waste water has been attempted to modify rice husk’s surface. The efficacy of the designed adsorbent derived using rice husk and its potential in removing the residual dyes has been evaluated in this research. Both raw silica and functionalized silica obtained from the rice husk have proved to possess greater ability than activated charcoal for the biosorption of dyes present in contaminated water. A comparative account of silica, functionalized silica and activated charcoal acting as biosorbent for a common acidic dye: EBT was studied using FT-IR, TEM, IR spectroscopy techniques for their characterization. It was also observed that adsorption tendency of adsorbent was governed by experimental condition directly. The variation in rates and thermodynamic factor also influences the adsorption efficiency. For the removal of EBT from waste water functionalized silica was revealed to be most efficient.

A novel and efficient methodology has been developed for synthesizing indane-1,3-dione and pyrimidine based spirocyclic compounds. The synthesis has been achieved via multicomponent reaction of indane-1,3-dione/1.3-dimethylbarbituric acid, variously substituted aromatic aldehydes and cyclohexylidene malononitrile in presence of catalytic amount of TSIL [bmim]OH. Short reaction time, high yields and use of non-chromatographic purification techniques are some of the advantages of this methodology.

Triazoles belong to a class of nitrogen containing compounds which are known for its highly valuable and versatile biological activities. More than 50 years ago, the first synthesis of tri-substituted triazoles was achieved by Huisgen via azide-alkyne cycloaddition. Over the years the remarkable achievement in triazole-based pharmacology promoted ample interest in the discovery of new synthetic methods and catalysts for the synthesis of this miraculous scaffold. Recent tri-substituted triazoles development based on various azides and double bonds have been summarized in this report.

Chemistry of Natural product is an ancient science. Secondary products present in the plants are responsible for beneficial medicinal effects of plant materials. This results from the combinations of these secondary metabolites. Harad is a species of Terminalia. Terminalia chebula (Harad) is one of the imperative herbs used for digestive problems. Harad is a magical herb and its fruit is used to treat acidity, heat burn, heart disease, constipation, ulcers, piles, inflammation, dysentery and diarrhea. Harad is considered as a remarkable medicine for its healing properties. It is also used to remove toxins from body. It is good for lungs, bronchitis and sinus. Terminalia bellirica, the Behada tree has medicinal values and uses in Ayurvedicpathy to removes all the three doshas. Behada fruit’s skin is beneficial in case of anemia, jaundice and white leprosy. The seeds Behada control vomiting, cures bronchitis. Baheda cure disorders of blood, along with voice disruption. Baheda is laxative, mild hot and destroys germs and eye diseases. Based on medicinal importance, an effort has been made to review the antibacterial properties and phytochemical analysis of Terminalia chebula (Harad), Terminalia bellirica (Baheda). S. aureus and E. coli bacterial strains were used for antibacterial activity. The antibacterial activity was determined by well diffusion method. The extract of Terminalia bellirica was more active against S. aureus than Terminalia chebula. Against E. coli both extracts showed almost same zone of inhibition.

In recent times electric rickshaw has been applauded as an environmentally sound and clean mode of transport. In contrast, the conventional fuel vehicles have proved to be extremely detrimental to the environment owing to their huge carbon emissions. This study is an attempt to quantify the impact of four modes of urban transit—e rickshaws, auto rickshaws, mini buses and buses, based on a primary survey of 220 e-rickshaw drivers from different areas of Delhi and methods of calculating carbon emissions adopted globally. The results conclude that the average kg of carbon emission is the lowest for the e-rickshaws as compared to the other fuel vehicles. However, the extent of contribution of e-rickshaws in greenhouse gas reduction is compromised due to carbon emissions from electricity generation required for charging the battery of the vehicle. Other challenges include disposal and recycling of lead batteries, energy losses and metal depletion which have environmental consequences of their own. As a result, the feasibility of solar batteries in e-rickshaws is explored. Finally, the paper suggests policy recommendations for improving the environmental profile of e-rickshaws. These include renewable sources for sustainable electricity generation, time of use electricity rates, a system of mother power stations to supply charged batteries to other local distribution points, and disposal and recycle systems of existing batteries.

The volumetric analysis allows the quantitative chemical analysis of a solution of the unknown concentration (acid/base) by titrating it with the solution of accurately known concentration (base/acid). For this purpose, chemicals indicators such as phenolphthalein, methyl orange, methyl red, congo red etc. are used. These indicators are expensive and some of them have toxic effects on users and can also cause environmental pollution. Therefore, an attempt has been made to investigate the indicator activity of some of the fruits, vegetables and kitchen spices. The current paper recommends the use of natural indicators such as Curcuma longa (turmeric), Beta vulgaris (beetroot), Citrus × limon (lemon), Citrus reticulata (orange), Citrus limetta (sweet lime), Solanum lycopersicum (tomato), etc. as a strategy for environment remediation, to reduce toxicity and to decrease the respective cost of the synthetic indicators. Various acid-base titrations were carried to ensure a sharp color change with respect to the pH of the medium. The promising results were obtained using comparative studies against standard synthetic indicators. Consequently, the authors suggest that these indicators can be used as pH indicators in the college laboratories for undergraduate courses.

Nucleosides and its modified analogues are important components and possess key roles in various biological processes. Copper catalyzed 1,3-dipolar cycloadditions have been emerged as an excellent tool to join azide and alkyne moieties to form triazolyl compounds. Presence of triazole group enhances the therapeutic potential as well as fluorescence properties of the modified nucleosides. Owing to the designing and development of the new triazolyl nucleosides for their various biological and photophysical application at faster pace, there is a need to have knowledge of the recent developments in this area. The review herein highlights the various modifications, therapeutic importance and other applications of recently reported triazolyl-nucleosides.

Study conducted to develop and validate laboratory method using QuEChERS method. QuEChER method was used for the determination of 28 pesticide residues belongs to organochlorine, synthetic pyrethroids and herbicides in Spinach. Sample was extracted by ethyl acetate. Removal of moisture using from sample extract by anhydrous sodium sulphate and magnesium sulphate. Cleaning of matrix and other interferences was done by Primary Secondary Amine (PSA), C18 and activated charcoal. Agilent 7890B model GC-ECD with 7693 auto sampler and 7890A-Agilent Technologies GC with 5975C inert XL EI/CI MSD triple axis mass detector with DB-5MS fused silica capillary column were used for analysis of samples taken for study. Each pesticide spiking concentration was 0.05 ppm level in three replicate whose recovery lies between Codex permissible limit i.e. 70–120%. Relative standard deviation (RSD) < 15%. Codex norms were followed for repeatability and reproducibility check of the instrument. For Linearity check, taking area of lambda cyhalothrin against five different concentration levels of 0.003, 0.010, 0.100, 0.70, 1.00 mg/kg, calibration curve was plotted with regression co-efficient (r²) 0.993. Total uncertainty or combined uncertainty comprise of three main independent uncertainties arise due to weighing of standards, purity of the standard and repeatability of instruments. Expanded uncertainty is twice of the combined uncertainty which lies in three ranges viz., (a) ≤10% (b) 11–15% and (c) 15–20%. All pesticides taken for study were in the range (a) i.e. ≤10%.

Intensive polarographic study of Cd(II) with amino acids (L-Serine, DL-Alanine) and the ligand 4,4,4-trifluoro-1-(2-napthyl)butane-1,3-dione have been carried out keeping constant ionic strength (μ = 1), at 308 K, by using KNO₃ in 60% Acetonitrile media. It was found that the reduction of all the systems taken, are diffusion controlled and reversible involving two electrons. For the simple system of Cd(II) with 4,4,4-trifluoro-1-(2-napthyl)butane-1,3-dione and Cd(II) with amino acids, the stability constants were determined first by DeFord and Hume and then evaluated by Schaap and McMaster method.

This research article refers to the synthesis and characterization of MnO₂ nanoparticles embedded on polypyrrole nanotubes. The product was synthesised by chemical oxidative polymerization method. Combination of MnO₂ nanoparticles and polypyrrole nanotubes enhance the capability of the nanocomposite. The microstructures and properties of Polypyrrole nanotubes (PPy) and MnO₂ embedded Polypyrrole nanotubes (PPy:MnO₂) were determined by TEM and SEM. FT-IR spectra was recorded to determine the chemical structure of the products. XRD was used to determine the crystalline structure of the products. The PPy:MnO₂ nanocomposite electrode shows substantial improvement in the redox performance compared to individual component PPy. The specific capacitance value of electrode material PPy:MnO₂ was found to be ~200 F g⁻¹ at 5 mV s⁻¹.

The effect of UV radiations and oil mediated UV radiations in removal of PCDDs and PCDFs congeners was studied. The effectiveness of photolytic degradation using groundnut oil was examined for removing tetra-, and octachlorinated congeners of dioxins and furans from contaminated soil by varying the intensity of UV radiation, exposure period and analyte concentration. All the four congeners tested were successfully degraded. The maximum removal of 50.61–62.3% of 2, 3, 7, 8-TCDD, 44.1–69.24% of 2, 3, 7, 8-TCDF, 35.0–56.03% of OCDD and 37.11–59.64% of OCDF was observed at an initial concentration of 2.5 and 5.0 ng g⁻¹ respectively after an UV exposure period of 24 h. The dioxin congeners in the soil sample showed decrease in concentration with the increase in the exposure time and intensity of UV radiations. More degradation of dioxin was found when the samples were exposed for 34 h using 400 W of UV lamp. The rate of photocatalytic degradation of polychlorinated dioxins was found to decrease with the increase in number of chlorines.

Cinnamon act as potential drug for lot of curable diseases such as Diabetes. For increasing its bioavailability as a drug, Nano encapsulation of cinnamon powder was carried out using solvent evaporation method. The effect of organic solvent and surfactant such as PVA(Polyvinylalcohol) and Pluronic F-68 was studied. The morphology and particle size of nanoparticles was studied using Scanning Electron Microscope (SEM). Drug release study for cinnamon and corresponding nanoparticles was also done. Results show that different surfactants have different impact on nanoparticles size and morphology. Nanoparticles obtained were in size range of 100–250 nm. The study reveals that cinnamon loaded PLGA nanoparticles has potential therapeutic efficiency and may be used in treatment of type II Diabetes.