Aegle marmelos (L.) Correa belongs to the family Rutaceae is generally known as “bael fruit tree” occuring across the south Asian countries. The current investigation screened the main derivatives from crude ethanolic extracts of the Bael tree leaf and evaluated activity effects on the larvae and adults of Aedes aegypti (L.) Dengue vector mosquito and a non-target aquatic predator. The GC-MS results showed that the peak area was found to be profound in N-methyl-1-adamantaneacetamide (N-M 1a) followed by oleic acid (OA) with 63.08 and 11.43% respectively. The larvicidal activity against the fourth instar larvae and the crude Ex-Am showed prominent mortality rate (93.60%) at the maximum dosage of 100 ppm. The mortality rate of N-M 1a and OA was occurred at 10 ppm (97.73%) and 12 ppm (95.4%). The repellent activity was found to be prominent at crude Ex-Am (50 ppm) as compared to the pure compounds (N-m 1a and OA) with maximum protection time up to 210 min. The non-target screening of Ex-Am, N-M 1a, and OA on mosquito predator Tx. splendens showed that they are scarcely toxic even at the maximum dosage of 1000 ppm (34.13%), 100 ppm (27.3%), and 120 ppm (31.3%) respectively. Thus, the present investigation clearly proved that the crude Ex-Am and their major derivatives Nm 1-a and OA showed their acute larval toxicity as well as potential mosquito repellent against the dengue mosquito and eco-safety against the mosquito predator.

Internal combustion engines are the inevitable prime movers in the contemporary engineering era. The suitability of proper bio-fuel and their blends plays a vital role in engine behaviour. This study aims to select smart fuel opus depending on Aegle marmelos (AM) fuel properties with nano additive blends for diesel engines by using intelligent hybrid decision-making tools. Physicochemical properties of CuO and novel graphene nano sheets added bio-oil combinations were studied. The assessment of an appropriate blend depends on the analysis of fuel properties. The Fuzzy Analytical Hierarchy Process (FAHP) integrated with Grey relational analysis (GRA) was employed for optimum fuel blend selection. The FAHP model was used to identify the criteria weights, whereas GRA was hired to rank alternative fuel blends. Pairwise analysis and ranking of the alternatives were compared to get the optimum fuel blend through FAHP and GRA amalgamation. The addition of nanoparticles enhanced engine performance and reduced emission. The obtained ascending order of preference of the bio-oil blends from FAHP and GRA analysis is AC15G15>AG30>AC30>A10>A20. From FAHP, GRA, and engine test results, it is observed that AC15G15 opus is the most suitable fuel blend for diesel engines. Lower fuel consumption (0.37 kg/kW hr) and emissions (CO level of 0.21%, which is 0.34% for diesel, HC value of 134 ppm, which is 184 ppm for diesel) of AC15G15 aids in contributing towards a green and clean environment.

In leather industries, raw hides/skins are always preserved before being processed into leather. Salting method of preservation is the general and age old popular practice of preservation used in these industries. The main drawbacks of this method are the generation of huge amounts of pollution load, in terms of total dissolved solids (TDS), total suspended salts (TSS), and chlorides; and ecological damage which occurs as a result of these waste effluents being discharged into the ground. Therefore, finding cheaper and eco-friendly methods of preservation has become a major necessity for these industries. In this manuscript, we have used ethanolic extract of Aegle marmelos for preservation which totally eliminates salt. The efficacy of this method was assessed by evaluating parameters such as microbial count, nitrogen content, and collagen content of the skin samples, and biological oxygen demand (BOD), chemical oxygen demand (COD), TDS, and TSS of the waste effluents collected during processing of leather. It was found that this method showed a remarkable reduction in pollution loads like BOD (46%), COD (3-fold), TDS (many folds), and increased values of collagen content. Thus, we could conclude that preservation using A. marmelos was found to be more effective and eco-friendly.

Aromatic substituted phenols and their by-products discharged from numerous industries are of environmental concern due to their toxic, carcinogenic, recalcitrant, and bioaccumulating properties. Therefore, their complete removal from waters by low-cost, efficient, environmentally friendly nanomaterial-based treatment techniques is desirable. Double metal cyanide complexes (DMCC) are the extremely useful heterogeneous and recoverable catalyst. Hence, green route has been developed for several DMCC and their photocatalytic efficiency was evaluated for degradation of toxic phenols. Herein, nanocubes for hexacyanocobaltate of iron (FeHCC ~ 200 nm), nickel (NiHCC < 10 nm), and zinc (ZnHCC ~ 500 nm) were synthesized after employing Aegle marmelos. Subsequently, at neutral pH and sunlight irradiation, 15 mg of catalysts were able to degrade the maximum extent of phenols (1 × 10⁻⁴ M) in the order: 3-aminophenol (96% ZnHCC > 94% FeHCC > 93% NiHCC) > phenol (94% ZnHCC > 92% FeHCC > 91% NiHCC) > 2,4-DNP (92% ZnHCC > 91% FeHCC > 90% NiHCC). This is attributed to highest basicity of 3-aminophenol containing excess of free electrons. Highest catalytic potential of ZnHCC (Xₘ = 0.54–0.43 mg/g) is because of its highest surface area and negative zeta potential along with sharp morphology and crystallinity. Adsorption of phenols over catalyst was statistically significant with Langmuir isotherms (R² ≥ 0.96; p value ≤ 0.05). Small and non-toxic by-products like oxalic acid, benzoquinone, (Z)-hex-3-enedioic acid, (Z)-but-2-enal, and (Z)-4-oxobut-2-enoic acid were identified in GC-MS. Degradation modes involving hydroxylation, oxidative skeletal rearrangement, and ring opening clearly supported enhanced oxidation of phenols by •OH. Overall, due to greater active sites, high surface activity, low band gap, and semiconducting nature, DMCC revealed promising potential for solar photocatalytic remediation of wastewater.

A novel magnetic bio-adsorbent was prepared from the leaves of Aegle marmelos tree (Indian bael) and Fe₂O₃ nanoparticles. The AMP@Fe₂O₃ nanocomposite (Aegle marmelos leaf powder) was synthesized by pyrolysis process and applied for As(V) removal through batch adsorption process. The synthesized AMP@Fe₂O₃ nanocomposite was analyzed by several instrumental techniques like XRD, FESEM, TEM, HRTEM, FTIR, BET, and VSM studies. Maximum amount of As(V) was removed at pH 3, contact time of 250 min, adsorbent dose of 0.1 g/L, and initial concentration of 0.5 mg/L at room temperature. The model study revealed that the pseudo-second-order kinetics and Langmuir isotherm models were best fitted with the experimental data. The nanocomposite showed a maximum adsorption capacity of 69.65 mg/g. The endothermic nature of the adsorption process was ascertained from the thermodynamics studies. The zeta potential and FTIR analysis before and after adsorption demonstrated two types of adsorption mechanism. The first one was the electrostatic attraction between negatively charged As(V) ions (H₂AsO₄⁻) and protonated −OH group present on the Fe₂O₃ surface and the second one was ligand exchange between the surface hydroxyl groups and As(V) ions. The AMP@Fe₂O₃ nanocomposite was desorbed with 0.5 M NaOH solutions and also used up to four cycles without any major decrease in removal efficiency. Thus, AMP@Fe₂O₃ nanocomposite can be applied as a potential adsorbent for As(V) removal from wastewater.

The demand for higher fuel energy and lesser exhaust emissions of diesel engines can be achieved by fuel being used and engine operating parameters. In the present work, effects of engine speed (RPM), injection timing (IT), injection pressure (IP), and compression ratio (CR) on performance and emission characteristics of a compression ignition (CI) engine were investigated. The ternary test fuel of 65% diesel + 25% bael oil + 10% diethyl ether (DEE) was used in this work and test was conducted at different charge inlet temperature (CIT) and exhaust gas recirculation (EGR). All the experiments are conducted at the tradeoff engine load that is 75% engine load. When operating the diesel engine with 320 K CIT, brake thermal efficiency (BTE) is improved to 28.6%, and carbon monoxide (CO) and hydrocarbon (HC) emissions have been reduced to 0.025% and 12.5 ppm at 18 CR. The oxide of nitrogen (NOx) has been reduced to 240 ppm at 1500 rpm for 30% EGR mode. Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) method is frequently used in multi-factor selection and gray correlation analysis method is used to study uncertain of the systems.

The present research focuses on the analyzing the characteristics of bio-oil derived from intermediate pyrolysis of Aegle marmelos (AM) seed cake and its suitability for C.I. engine adaptation. Owing to the high volatile matter content of 73.69%, Aegle marmelos biomass was selected as the feedstock for this research. The intermediate pyrolysis was carried out at 600 °C in a 2-kg fixed bed type pyrolysis reactor at a heating rate of 10 °C/min and the obtained bio-oil was characterized by different analytical methods. As per American Society for Testing and Materials (ASTM) standards, physicochemical properties of the bio-oil were tested and it was observed that bio-oil is a highly viscous fluid with low calorific value. Analysis of bio-oil through FT-IR and GC-MS examination confirmed the presence of phenol, esters, alkyl, and oxygenated compounds. The performance and emission testing of direct injection diesel engine were conducted with various bio-oil blends and the results were compared with baseline diesel fuel. The experimental results showed that the addition of bio-oil decreased BTE (%) while increasing the BSEC (MJ/kW-h). At the same time, increasing the bio-oil ratio with diesel decreases dangerous emissions such as carbon monoxide and oxides of nitrogen emissions in the engine exhaust. According to engine test result, it was suggested that up to 20% of AM bio-oil (F20) can be employed as engine fuel for better engine operating characteristics.

Atmospheric pollution by opencast mining activities affects tree species around the mining area. The present study evaluated the responses of five native tree species to air pollution in Jharia coalfield. Sites were selected as closest to farthest from the mining area. Foliar dust deposition and foliar sulphate content affected stomatal conductance, superoxide dismutase activity and ascorbic acid and, thus, increased the susceptibility of sensitive species. Ficus benghalensis and Butea monosperma showed maximum dust deposition, while Adina cordifolia showed minimum deposition. Maximum dust deposition in Ficus benghalensis lowered stomatal conductance and, thus, checked the flux of other acidic gaseous pollutants which led to minimum variation in leaf extract pH. Higher stomatal conductance in Adina cordifolia and Aegle marmelos, on the other hand, facilitated the entry of acidic pollutants and disrupted many biological functions by altering photosynthesis and inducing membrane damage. Low variations in Ficus religiosa, Ficus benghalensis and Butea monosperma with sites and seasons suggest better physiological and morphological adaptations towards pollution load near coal mining areas. Tree species with better adaptation resisted variation in leaf extract pH by effectively metabolising sulphate and, thus, had higher chlorophyll content and relative water content.

This research focuses on the detailed experimental assessment of compression ignition (CI) engine behavior fuelled with Aegle marmelos (AM) seed cake pyrolysis oil blends. The study on effects of engine performance and emission a characteristic was designed using L₂₅ orthogonal array (OA). These multi-objectives were normalized through gray relational analysis (GRA). Likewise, the principal component analysis (PCA) was performed to assess the weighting values respective to every performance and emission characteristics. The variability induced by using the input process parameters was allocated using analysis of variance (ANOVA). Hence, GRA-coupled PCA were employed to determine the optimal combination of CI engine control factors. The greater combination of engine characteristics levels were selected with F₅ and W₅. The higher brake thermal efficiency (BTE) have been obtained for F20 fuel as 22.01% at peak engine load, which is 11.43% for diesel. At peak load condition, F20 fuel emits 14.99% lower HC and 18.52% lower CO as compared to diesel fuel. The improved engine performance and emission characters can be attained by setting the optimal engine parameter combination as F20 blend at full engine load condition. The validation experiments show an improved average engine performance of 67.36% and average lower emission of 64.99% with the composite desirability of 0.8458.

The present study aims towards fluoride remediation from synthetic water using steam-activated carbon of Aegle marmelos (bael shell/wood apple) (BAC) and Parthenium hysterophorus (PHAC) according to batch sorption techniques. The impact of different parametric conditions viz. initial fluoride concentration (4–12 mg/L), time (0–5 h), temperature (293.15–333.15 K), adsorbent dosage (4–14 g/L), pH (4–9), and RPM (150–350) were considered for both the adsorbents. Maximum defluoridation of 89% was achieved by BAC at a concentration of 10 mg/L, adsorbent dose 6 g/L, pH 5, temperature 313.15 K, agitation speed 250 rpm, and contact time 9 h, whereas PHAC attained maximum removal of 78% at an initial concentration of 8 mg/L, adsorbent dose 10 g/L, pH 4, temperature 313.15 K, and contact time 12 h. Instrumental analysis by SEM, EDX, and FTIR confirmed about the fluoride binding ability of the adsorbents. The Langmuir isotherm model provided the best fit (R² = 0.9962 and 0.9945) to the removal process with maximum adsorptive uptake of 16.85 and 6.22 mg/g by BAC and PHAC respectively. The adsorption phenomenon was found to obey pseudo-second-order kinetics. The endothermic, spontaneous, and feasible nature of the sorption process was confirmed by the thermodynamic study. The total costs of 1 kg adsorbent preparation were calculated as 1.122 USD and 1.0615 USD which helped us in determining the economic feasibility of the adsorbents in large-scale applications. The growth of Chlorella sorokiniana BTA 9031 was also observed to be affected by the fluoride solution. Comparing the removal efficiencies of both the adsorbents, it can be concluded that BAC shell proved to be an efficient adsorbent over PHAC for fluoride elimination from aqueous solution. Graphical abstract Defluoridation of aqueous solution using biochar derived from Aegle marmelos shell and Parthenium hysterophorus.