Cedrus deodara is a coniferous tree native to Himalayan region. Its wood is a valuable resource for the timber industry; however, its bark is typically discarded as a waste material. The present study examines the performance of Cedrus deodara bark powder (CD) as an inexpensive adsorbent for elimination of Pb (II) ions. In addition to this multiple linear regression (MLR) and artificial neural network (ANN) models were developed for modelling the adsorption process and prediction of Pb (II) removal efficiency. The structural and chemical properties of CD were explored using Field Emission Scanning Electron Microscope (FE-SEM), Energy Dispersive Spectrometer (EDS), X-Ray Diffractometer (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). Batch experiments were conducted to investigate the influence of factors including pH, contact time, initial Pb (II) concentration and temperature on Pb (II) adsorption. The adsorption followed pseudo-second-order kinetic and Langmuir isotherm models with maximum monolayer uptake capacity 77.52 mg/g. Based on the thermodynamic criteria, the process was endothermic and spontaneous with enthalpy change (ΔH = 8.08 kJ/mol), free energy change (ΔG = -2.44 kJ/mol) and entropy change (ΔS = 0.03 kJ/K/mol). Statistical comparison of MLR model (R2 = 0.817, RMSE = 8.954, MAPE = 17.379 %) and ANN model (R2 = 0.993, RMSE = 1.777, MAPE = 2.054 %) confirmed that ANN model was far more accurate in predicting removal efficiency.

Phytoremediation is one of the non-energy consuming processes of remediating polluted water. However, the disposal of post-remediated plants poses a threat of the re-introduction of pollutants back into the ecosystem. Re-routing remediated pollutants for commercial application could be one way to reduce the re-introduction of pollutants in an ecosystem. Heavy metal pollution in water bodies is one issue, which can be mitigated to an extent with phytoremediation. In the current study, the effect of heavy metal phytoremediation on the phytochemical fingerprint and bioactivity of Pistia stratiotes L. was investigated. Pistia stratiotes L. was subjected to different concentrations of iron (Fe) and lead (Pb), in the range of 5-20 ppm. Different parameters such as heavy metal estimation (in plants and water post-treatment), thin layer chromatography (TLC), antioxidant activity, and antiurolithic activity were measured. Post remediation, heavy metal concentration was found to be comparatively higher in roots (16.515 ± 0.008 mg.g-1 and 5.25 ± 0.086 mg.g-1 when treated with 15 ppm iron and lead respectively). TLC revealed differences between the fingerprints of treated and untreated plants. Some bands increased in intensity as the concentration of heavy metal increased, while some bands which were present in untreated, were absent in treated plant samples. Antioxidant activity of treated plants shows lesser IC50 values, compared to untreated, in that, treated leaves show better activity (IC50 = 1.8 ± 0.5220 mg.mL-1 of leaf treated with 2 ppm iron as opposed to IC50 > 5 mg.mL-1 of untreated leaf extract). The treated plants revealed good antiurolithic activity compared to untreated, in that, the percentage inhibition showed by Iron treated leaves and roots was better (96.87% and 98.95% exhibited by iron-10 ppm treated leaves and roots respectively), while the untreated showed a maximum of only 68.75% inhibition. The results suggest that the bioactivity of the plant extracts increases post-remediation. Potential applications of these extracts can be explored such as nanoparticle synthesis, drug discovery, etc.

Mauritania is a fishing country. However, the Mauritanian coast is increasingly exposed to environmental issues mainly due to anthropogenic activities such as the mining, gas, oil, and fishing industries, as well as new agricultural practices that unreasonably use inputs. Environmental monitoring of the Mauritanian coast faces several challenges; thus, improving the fisheries sector begins with enhancing the state of marine ecosystems and implementing environmental monitoring adapted to climatic conditions and local needs. This study aims to evaluate the quality of the sediments of the “Baie du Repos” in the town of Nouadhibou, Mauritania, through the study of organic matter and the quantification of trace metallic elements in the Quaternary sediments of the Bay. Six samples deemed representative of this Bay were taken and transported to the laboratory. The physicochemical analysis of these samples shows that the superficial horizons of 30 cm depth have overall organic matter contents higher than the average threshold value proposed by the literature for 4 out of 6 of the points studied. The contents recorded for the different metallic trace elements indicate that point 1 is the most exposed to contamination, with the highest concentrations of cadmium, lead, copper, iron, and zinc. The ACP (Principal Component Analysis) showed that the metallic trace elements Pb, Cu, Fe, Cd, and Zn are closely related and evolve positively in the same direction. Additionally, it was found that the points studied are divided into three groups: Group 1 contains only point 1, which is the most exposed to contamination by these toxic elements (Pb, Cu, Zn, Fe, and Cd). Group 2 contains points 3, 5, and 6, which are moderately contaminated by metallic elements with a significant dominance of organic matter (OM). Finally, Group 3 is the least contaminated, with a very high content of organic matter (OM).

India’s fast industrialization and population expansion have resulted in heavy metal accumulation from many operations, which has caused massive waste generation and poisoning of soils. Therefore, it is necessary to design reclamation to improve th T.Ne soil. Phytoremediation presents itself as a viable, economical, and environmentally sustainable solution to this problem. This study was carried out by using plants namely, aloe-vera (Aloe-Barbadensis), tulsi (Ocimum Tenuiflorium), and vetiver (Chrysopogon Zizanoides) plants which were planted in a simulated soil of Cd, Zn and Pb, for 4 weeks. The sample of plant and soil were taken in 9 different pots, (15 cm diameter and 25 cm height) among 9 potted soils one will be tested as a controlled sample. An aqueous solution of lead, cadmium and zinc were added separately to the dry soil samples. The moisture level of the soil was maintained to near field water capacity (35.6%) and equilibrated for two weeks. The saplings of vetiver grass, aloe vera and tulsi were selected and pruned (the shoots were originally 20 cm high and the roots 8 cm long), and then transplanted into the pots. The AAS test was conducted after 4 weeks of growing in simulated soil. Tulsi demonstrated the highest efficacy in reducing Zn concentrations from 300 mg/kg to 188.3 mg/kg, followed by vetiver (179.3 mg/kg) and Aloe vera (158.3 mg/kg). Similarly, for Pb, tulsi exhibited the most substantial reduction (from 600 mg/kg to 188.3 mg/kg), followed by vetiver (164.3 mg/kg) and Aloe vera (179.6 mg/kg). Regarding Cd, tulsi reduced concentrations from 80 mg/kg to 18.62 mg/kg, while vetiver achieved a 17.62 mg/kg reduction. The result highlights Tulsi’s superior remediation potential, attributed to its efficient heavy metal uptake and translocation mechanisms. Thus, using these plants in the phytoremediation process, the heavy metals are extracted more economically than other plants. This technique highlights the innate ability of hyper-accumulator plant species, which flourish in situations high in heavy metals, to extract contaminants from contaminated soil.

Lead contamination poses a major threat to health and environmental well-being. The remediation of this heavy metal from water sources is essential to safeguard health and ensure access to clean water. In this study, Peanut hull was used as a biosorbent for lead (Pb) removal from water. It focuses on optimizing various parameters important for lead removal. Statistical analysis, such as the Kruskal-Wallis test, was done to assess the significance of these parameters on lead biosorption, and an inverse variance weighting technique was employed to derive the weighted contribution of each variable for fixed Pb removal categories in the range of 80-100% and 80% (below). On analysis, it was found that factors such as pH and biomass dosage played major roles in lead removal. Furthermore, Scanning Electron Microscopy (SEM) and Energy-dispersive X-ray Spectroscopy (EDS), were done to find out changes in the structural and elemental characteristics of peanut hull after lead sequestration. Overall, this study highlights the potential of peanut hull as a promising biosorbent for lead removal from water, thereby offering a sustainable solution to water contamination with heavy metals.