Mitigation of air pollution by plants is a well-established phenomenon. Trees planted on the roadside are known to reduce particulate matter pollution by about 25%. In an urban ecosystem, especially in a metropolitan city such as Delhi, roadside trees are constantly exposed to air pollution. We, therefore, evaluated the effect of air pollution on a common Indian roadside tree, Neem (Azadirachta indica), and its associated microbes in areas with high and low levels of particulate matter (PM) pollution in Delhi. We hypothesized that alteration in the air quality index not only influences plant physiology but also its microbiome.A 100-fold increase in the number of epiphytic and 10–100 fold increase in endophytic colonies were found with 1.7 times increase in the level of pollutants. Trees in the polluted areas had an abundance of Salmonella, Proteus and Citrobacter, and showed increased secondary metabolites such as phenols and tannins as well as decreased chlorophyll and carotenoid. The number of unique microbes was positively correlated with increased primary metabolites.Our study thus indicates that, alteration in air quality affects the natural micro-environment of plants. These results may be utilized as sustainable tools for studying plant adaptations to the urban ecosystem.

Treated wastewater is an invaluable resource in meeting the growing demand of freshwater in tree crop irrigation in dry areas with additional benefits of land degradation reduction and biomass production. Seedlings of Acacia nilotica, Azadirachta indica, Eucalyptus camaldulensis, Prosopis cineraria, P. juliflora, Tamarix aphylla, Salvadora persica, S. oleoides and Tecomella undulata were planted and irrigated with bore-well (BW) and treated wastewater (WW) at ½ET (evapotranspiration) and ¾ET. Changes in soil properties and plant biomass allocation in different parts were assessed for species efficacy in phytoremediation of wastewater-contaminated soils and enhanced biomass yield. Irrigation enhanced soil pH, EC, SOC, available nutrients (greater in 0–30-cm soil layer than in 30–60-cm soil layer) and plant biomass. Wastewater irrigation had stronger effect in enhancing soil EC, SOC, NH₄-N and NO₃-N (3.50–76.92%), whereas increased quantity of irrigation showed stronger effects on PO₄-P, K, and root and shoot biomass (7.63–51.20%). High biomass in A. nilotica, A. indica, E. camaldulensis and P. juliflora plants was supported by increased root biomass to exploit increased level of water and nutrients. Indigenous S. oleoides, T. undulata, P. cineraria and S. persica showed greater potential of salts and nutrient absorption from the wastewater-contaminated soils. Moderate increase in pH and EC with simultaneous increase in SOC, nutrients and biomass exhibited beneficial use of wastewater in dryland afforestation. A. nilotica, A. indica, E. camaldulensis and P. juliflora were most efficient in utilising treated wastewater and beneficially can be utilised in urban afforestation and sustainable development of dry areas.

Carbonized wood is a biofuel from cellulose pyrolysis with frequent smoke and life-threatening carcinogenic emissions. Carbon monoxide (CO), particulate matter (PM₂.₅), metalloids and trace elements from charcoals from six commonly used tropical timbers for carbonization in Donkorkrom (Ghana) were assessed. During combustion, Anogeissus leiocarpa charcoal emitted the least CO (4.28 ± 1.08 ppm) and PM₂.₅ (3.83 ± 1.57 μg/m³), while particulate matter was greatest for Erythrophleum ivorense (28.05 ± 3.08 ppm) and Azadirachta indica (27.67 ± 4.17 μg/m³) charcoals. Erythrophleum ivorense charcoal produced much lead (16.90 ± 0.33 ppm), arsenic (1.97 ± 0.10 ppm) and mercury (0.58 ± 0.003 ppm) but the least chromium (0.11 ± 0.01 ppm) and zinc (2.85 ± 0.05 ppm). Nickel was greatest for A. indica charcoal (0.71 ± 0.01 ppm) and least for Vitellaria paradoxa (0.07 ± 0.004 ppm). Trace elements ranged from 342.01 ± 2.54 ppm (A. indica) to 978.47 ± 1.80 ppm (V. paradoxa) for potassium and 1.74 ± 0.02% (V. paradoxa) to 2.24 ± 0.10% (A. indica) for sulphur. Besides A. leiocarpa charcoal, which ranked safest during combustion, the high PM₂.₅ and CO emissions make the other biofuels hazardous indoors. Kitchens need air filters to absorb these emissions together with the use of improved cook stoves. These carcinogenic metalloids would necessitate that their ashes be properly discarded without human contact. Yet, the charcoals would be much suitable as soil amendment bio-char for plant growth quality improvement.

Sustainability in all applied fields particularly in textiles is to protect our globe, environment, and community, where green dyed products are playing their role. For the current study, Esfand (Peganum harmala) has been explored using a green isolation tool, i.e., ultrasonic (U.S.) rays, and applied onto fabric. Different dyeing parameters have been explored statistically through response surface methodology by employing temperature (50–80°C), time (25–65 min), extract volume (15–55 mL), salt (1–5 g/100 mL), and dye bath pH (4–7) through series of experiments. For developing new shades, green mordants such as elaichi, neem, turmeric, and zeera have been utilized. It has been found that exposure of 35 mL extract of 7 pH containing 3 g/100 mL of salt as exhausting agent to U.S. rays for 30 min for the dyeing of silk at 70°C for 45 min has given maximum color strength with reddish-yellow shades. Color characteristics obtained in the CIE Lab system reveal that 5% of turmeric as meta bio-mordant has given good quality reddish-yellow shades. It is found that U.S. rays have not only good potential to isolate colorant followed by dyeing of silk under reduced condition but also the application of bio-mordants have made the process more greener, sustainable, and cleaner.

Improving digestibility, fermentation characteristics, and reducing greenhouse biogases to protect the environment without the use of synthetic materials is an important goal of modern-day farming and nutritionist. Plant extracts are capable of solving these. This is due to the digestive enzymes and the bioactive components capable of performing antimicrobial functions inherent in these plants. This study was aimed to investigate the effect of standard maize substrate treated with selected herbs and spices extracts on ruminal environmental biogas production and pressure during fermentation via biogas production technique. Herbs (Azadirachta indica leaves (T1), Moringa oleifera leaves (T2), Ocimum gratissimum leaves (T3) and spices (Allium sativum bulb (T4), Zingiber officinale rhizome (T5)) were harvested, air dried, and milled using standard procedures. Methanolic extracts of the herbs and spices were prepared and used as additives at different concentrations (50, 100, and 150 μL) to the maize substrate for in vitro biogas production. Data were analyzed using regression analysis. There were significant (P < 0.05) differences across all the treatments on the volume and pressure of biogas. The pressure and volume of biogas when compared with the levels tested showed differences (P < 0.05) across all the treatments for the prediction of volume from pressure of biogas. The pressure and volume of gas produced in vitro increased (P < 0.05) and biogases decreased (P < 0.05) by the substrate treated with herbs and spices but for the drum stick leaves which was similar for the levels of concentration tested. This means that the level tested had a pronounced mitigation effect on pressure of biogas and volume of biogas produced. It was concluded that the herb and spice extracts have the potential to improve rumen fermentation and reduce the production of biogases in ruminant diet.

Particulate matter (PM) is one of the most dangerous pollutants in the air. Urban vegetation, especially trees and shrubs, accumulates PM and reduces its concentration in ambient air. The aim of this study was to examine 10 tree and shrub species common for the Indian city of Jodhpur (Rajasthan) located on the edge of the Thar Desert and determine (1) the accumulation of surface and in-wax PM (both in three different size fractions), (2) the amount of epicuticular waxes on foliage, (3) the concentrations of heavy metals (Cd and Cu) on/in the leaves of the examined species, and (4) the level of heme oxygenase enzyme in leaves that accumulate PM and heavy metals. Among the investigated species, Ficus religiosa L. and Cordia myxa L. accumulated the greatest amount of total PM. F. religiosa is a tall tree with a lush, large crown and leaves with wavy edge, convex veins, and long petioles, while C. myxa have hairy leaves with convex veins. The lowest PM accumulation was recorded for drought-resistant Salvadora persica L. and Azadirachta indica A. Juss., which is probably due to their adaptation to growing conditions. Heavy metals (Cu and Cd) were found in the leaves of almost every examined species. The accumulation of heavy metals (especially Cu) was positively correlated with the amount of PM deposited on the foliage. A new finding of this study indicated a potentially important role of HO in the plants’ response to PM-induced stress. The correlation between HO and PM was stronger than that between HO and HMs. The results obtained in this study emphasise the role of plants in cleaning polluted air in conditions where there are very high concentrations of PM.

Collagen is a promising candidate for food and pharmaceutical applications due to its excellent biocompatibility, low antigenicity, and controlled biodegradability; however, its heavy price restricts its utilization. Fish scales generated during the processing are generally regarded as waste material and an environmental pollutant, though they are a promising source of collagen. In the present study, Cirrhinus mrigala scales were demineralized and extracted for acid-soluble collagen (ASC) using acetic acid, with a collagen yield of 2.7%. UV–Vis spectra, SDS-PAGE, FTIR analyses, and amino acid composition confirmed the type I nature of the collagen extracted. The denaturation temperature of the collagen was found to be 30.09 °C using differential scanning calorimetry (DSC). The collagen was highly soluble at acidic pH and lower NaCl concentrations while its solubility was lowered in alkaline conditions and NaCl concentrations above 0.5 M. The collagen exhibited good emulsifying potential with an emulsion activity index (EAI) and emulsion stability index (ESI) of 21.49 ± 0.22 m² g⁻¹ and 15.67 ± 0.13 min, respectively. Owing to the good physicochemical characteristics of the extracted collagen, collagen-chitosan-neem extract (CCN) films were prepared subsequently which showed good antimicrobial activity against Bacillus subtilis NCIM 2635, Staphylococcus aureus NCIM 2654, Escherichia coli NCIM 2832, and Pseudomonas aeruginosa NCIM 5032, suggesting the potential of collagen in the development of antimicrobial films. These results demonstrate that the collagen from fish waste could be valorized and used effectively along with chitosan and neem extract for the synthesis of novel biodegradable films with antimicrobial efficacy.

The fruits and vegetable waste has become the highest compared with the production rate. These types of wastes had reached up to 70% by 2019–2020 as estimated by Food and Agriculture Organization (FAO). Improvisation of the performance of still using fibre insulation (Artocarpus heterophyllus rags and Azadirachta indica gum (AHRAIG)) has been carried out in this study. Potable water demand in arid areas is a vast problem where fresh water is very expensive. The proposed solar still (PSS) retains the basin temperature and raises the rate of evaporation. Rags are latex-like filament extracted from the waste of the jackfruit peels and an adhesive agent from Azadirachta indica tree. A comparison is made among still without insulation (SWI), still with polystyrene insulation (SPI) and still with fibre insulation (SFI) in producing the fresh water under same ambient conditions. The experiments result a promising yield of 9.3% rate of rise of potable water produced using AHRAIG insulation related to conventional still. The energy efficiency is premeditated as 26.45%, while the exergy efficiency is 4.07%. The production of the potable water reached 2.58 L/m² for still with polystyrene insulation, 3.26 L/m² for fibre insulation and 1.93 L/m² for still without insulation, respectively.

Release of colouring agents into the environment alarms the need to design a cheap, quick and safe process. Owing to environmental safety concern, synthesis of two metal hexacyanoferrates (MHCFs) based on cadmium (CdHCF) and manganese (MnHCF) was carried out using natural plant extract of Azadirachta indica and water as a solvent. Synthesized MHCFs were utilized for the removal of an acid dye (fuchsin acid, FA) and a xanthenes dye (rhodamine B, RB). The reactions were optimized at various conditions of dye concentration, catalyst dose, reaction pH, time and source of light. The MHCFs showed excellent results with both the dyes within very limited span of time (2 h). Consequently, 98% of FA and 97% of RB were degraded with 10 mg of CdHCF, at neutral pH and under sunlight. The degradation process followed the first-order reaction kinetics having t₁/₂ around 0.3 min. The MHCFs exhibited difference of only little percentage in degradation owing to a very slight difference between their surface areas (CdHCF: 54.1 m² g⁻¹; MnHCF: 49.7 m² g⁻¹). The synthesised nanocatalysts were stable as indicated by their higher negative zeta potential values. The adsorption of dyes was found to be maximum with CdHCF having Xₘ value 19.69 mg g⁻¹ and 18.15 mg g⁻¹ for FA and RB, respectively. Photocatalytic degradation involved the main role of hydroxyl radical as indicated by decline in activity of nanocatalyst in the presence of scavengers. All in all, this study presents highly active nanomaterials with higher surface area, stability and semiconducting properties under natural conditions.

Green vegetation enrichment is a cost-effective technique for reducing atmospheric pollution. Fifteen common tropical plant species were assessed for identifying their air pollution tolerance, anticipated performance, and metal accumulation capacity at Jharia Coalfield and Reference (JCF) site using Air Pollution Tolerance Index (APTI), Anticipated Performance Index (API), and Metal Accumulation Index (MAI). Metal accumulation efficiencies were observed to be highest for Ficus benghalensis L. (12.67mg/kg) and Ficus religiosa L. (10.71 mg/kg). The values of APTI were found to be highest at JCF for F. benghalensis (APTI: 25.21 ± 0.95), F. religiosa (APTI: 23.02 ± 0.21), Alstonia scholaris (L.) R. Br. (APTI: 18.50 ± 0.43), Mangifera indica L. (APTI: 16.88 ± 0.65), Azadirachta indica A. Juss. (APTI: 15.87 ± 0.21), and Moringa oleifera Lam. (APTI: 16.32 ± 0.66). F. benghalensis and F. religiosa were found to be excellent performers to mitigate air pollution at JCF as per their API score. Values of MAI, APTI, and API were observed to be lowest at reference sites for all the studied plant species due to absence of any air polluting sources. The findings revealed that air pollution played a significant impact in influencing the biochemical and physiological parameters of plants in a contaminated coal mining area. The species with the maximum MAI and APTI values might be employed in developing a green belt to minimize the levels of pollutants into the atmosphere.