Food waste is a matter of deep concern as it is creating multidimensional threats to the environment. Though these are potential sources of plant nutrients, a detailed investigation has not yet been conducted. Hence, a physico-chemical characterization of non-edible food waste such as brinjal waste, potato peels, banana peels, orange peels, eggshells, cow bones, chicken bones, fish bones, and their combined waste was accomplished using FTIR, TGA, XGT-5000, CHN corder, etc. The present study revealed that plant waste samples had lower ash contents (1.36–7.79%) but higher volatile matter (72.33–80.04%), and the reverse was true in animal waste. In addition, animal waste, except eggshells (22.48%), had lower fixed carbon (1.01–2.83%). On the other hand, fruit waste was documented with higher fixed carbon (11.33–14.27%). Results also indicated that animal waste and their combined samples, except eggshells, contained more nitrogen (3.82–5.06%). The concentration of P was statistically significant in the combined fruit sample (28.21% ± 8.451), followed by banana peels (24.96% ± 11.644). Vegetable waste contained a significantly higher amount of K (24.90% ± 28.311–37.92% ± 24.833) than other waste. Maximum Ca (68.82% ± 10.778) and Mg (15.37% ± 29.88) were recorded in eggshell and fish bone waste, respectively. Except for Zn and Mn in eggshells, the waste studied contained a significant amount of micronutrients. FTIR demonstrated the presence of different functional groups such as alcoholic group (OH), aliphatic chain (C–H), aromatic chain (C–H), alkyl aryl ether (C–O), carbonyl group (C=O), alkene (C=C), thiocyanate (S–CN), isothiocyanate (N=C=S), allene (C=C=C), sulphate (S=O), amine (N–H), and NO stretching band, which varied with the waste used. Thermogravimetric analysis revealed that plant waste degraded more quickly than animal waste. Eggshells were found to be less degradable by increased temperature, followed by cow bones > fish bones > chicken bones. The waste material used in the study was slightly acidic (6.67–6.82) in nature. Correlation analysis of the nutrients showed mainly positive relations in all samples for macro and micronutrients. Therefore, non-edible food waste can be a possible source of plant nutrients.

Ibuprofen is a significant nonsteroidal anti-inflammatory drug that poses environmental and health risks when present in wastewater because of its persistence and probable toxicity. This study investigates the use of banana peel biochar (BPB) made at 600 °C to 900 °C to eliminate ibuprofen from aqueous solutions. The uniqueness of this work lies in the high-temperature pyrolysis process, which has not been previously explored for the ibuprofen removal efficiency using BPB. The batch experiment was conducted considering initial concentrations, pH, and contact time. The data were compared with different algorithms, with Linear Regression (LR), Support Vector Machines (SVM), Decision Trees (DT), Random Forest (RF), and k-Nearest Neighbor (k-NN) to forecast the performance. The results revealed that banana peel biochar at 900 °C exhibited the highest ibuprofen removal efficiency (69.28 ± 0.83%) at 125 mg/L concentration with the sequence of BPB900 > BPB800 > BPB700 > BPB600. A maximum removal efficiency of 72.67 ± 0.75% was observed at pH 9. Adsorption behavior was analyzed using isotherm and kinetic models, with the Freundlich isotherm model (R² value 0.9620) indicating heterogeneous adsorption and the pseudo-second-order (PSO) kinetic model (R² value 0.9969) suggesting that physicochemical interactions govern the process. FTIR analysis ensured the existence of functional groups (hydroxyl, carboxylic, carbonyl, and aromatic rings) responsible for adsorption. Machine learning algorithms, especially RF, demonstrated outstanding performance with 90.07% accuracy in predicting the experimental data. In comparison to other adsorbents, BPB demonstrated superior removal efficiency, underscoring its effectiveness. The study suggests that BPB, particularly at 900 °C, is effective in removing ibuprofen, and due to its sustainable production, it offers a potential solution for wastewater treatment.

Polycyclic aromatic hydrocarbons (PAHs) are a matter of deep concern as they pose significant environmental and health hazards due to their persistence, bioaccumulation, and toxic effects. In soils, PAHs accumulate, contaminating ecosystems, entering food chains, and posing threats to plant and human health. This study conducted a comprehensive assessment of PAH contamination in agricultural soils (particle size < 20 µm) across various land-use categories and depths to determine contamination levels and associated health risks, as such comprehensive studies are very rare in Bangladesh. Soil samples were investigated using gas chromatography–mass spectrometry (GC–MS). The findings revealed that the concentrations of ∑16PAH ranged from 299 to 1928 µg/kg, with the lowest levels observed in research areas and the highest in industrial soils. Concentration trends were as follows: industrial areas > coastal areas > local market areas > rural areas > research areas. Higher concentrations were noted for individual PAHs such as Nap, Phe, BbF, and BkF (313.14 µg/kg ± 62.01 to 546.97 µg/kg ± 146.76), while the lowest concentrations were recorded for BghiP, DBahA, and Ind (1.25 µg/kg ± 1.10 to 5.74 µg/kg ± 3.77). PAH levels were highest in surface soils, following a depth sequence of 0–5 cm > 5–10 cm > 10–15cm. The results also showed that low-, intermediate-, and high-molecular-weight PAHs comprised 46.06–83.18%, 16.47–48.68%, and 0.23–6.51% of total PAHs, respectively. The source of PAHs was identified as integration of pyrogenic petrogenic. Children were found to have higher exposure through ingestion compared to adults, with lower exposure through inhalation and dermal pathways. The total incremental lifetime cancer risk (ILCR) for children ranged from 2.03 × 10⁻⁸ to 9.07 × 10⁻⁷, and for adults from 1.96 × 10⁻⁸ to 8.04 × 10⁻⁷. Both groups exhibited no carcinogenic risk, as per the USEPA threshold. These findings underscore the need for ongoing monitoring and management strategies to mitigate PAH contamination in agricultural soils, thus protecting environmental and public health concerns.

Heavy metal pollution is a growing public health concern owing to rising environmental pollution throughout the world. The situation is more vulnerable in Bangladesh; therefore, this study assessed contamination levels in different land use categories such as rural, local market, industrial, research, and coastal areas, as well as the related health risks for farmers in Bangladesh. A total of 45 soil samples were considered from three depths (0–5 cm, 5–10 cm, and 10–15 cm) across five different areas, with three replications per depth, following the monsoon season. Samples were prepared using a diacid mixture, and heavy metals (Cu, Ni, Mn, Cr, Zn, Pb) were investigated using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Health risks were evaluated using standard assessment models. The results showed that coastal agricultural soils had the highest heavy metal concentrations (except Pb), while rural areas had the lowest (except Cu and Ni), with no clear depth-based pattern. Two contamination sources were identified: component 1 (Cu, Ni, Mn, Cr, Zn) and component 2 (Pb, Zn), indicating mixed and anthropogenic sources, respectively. The Pollution Load Index (PLI) was highest in coastal areas and lowest in rural areas. The average daily intake of metals followed the order of inhalation > dermal > ingestion, with inhalation being the primary exposure route. The highest cumulative cancer risk (CCR) was observed in coastal agricultural soils (5.82 × 10⁻⁹), while rural soils had the lowest CCR (8.24 × 10⁻¹⁰), highlighting significant regional differences in health risks.