ABSTRACT This study aims to develop a photo‐induced nano‐adsorbent material derived from watermelon leaves (WML) by incorporating green‐synthesized titanium dioxide nanoparticles (TiO 2 NPs) using Pigeon Pea leaves extract. The prepared nano‐adsorbent will significantly reduce reliance on traditional chemical‐based methods for its synthesis. Morphological and structural studies confirm the successful formation of spherical TiO 2 NPs with an average size of 48 nm, whereas FESEM‐EDX studies further validate the incorporation of NPs within the bio‐adsorbent, and BET analysis demonstrates a substantial improvement in specific surface area from 31.6 to 96.99 m 2 /g after incorporating TiO 2 NPs in WML. The prepared nano‐adsorbent was used for removing Cr (VI) from industrial wastewater, and the results depict the highest Cr (VI) adsorption percentage, up to 90% compared to pristine WML at optimized conditions. Kinetics and isotherm findings predict the pseudo‐second‐order model (chemisorption‐controlled), and the Langmuir isotherm provides the best‐fitting model to the experimental data. Response surface methodology (RSM) using central composite design (CCD) reflects good agreement between actual and predicted value under optimized condition signify the reliability and adequacy of the predicted model. Moreover, the antibacterial efficacy of the prepared nano‐adsorbent was studied against Escherichia coli ( E.coli ) using extended Derjaguin–Landau–Verwey–Overbeek (XDLVO) theory in terms of adsorbent surface charge and interfacial interactions between the foulant and the adsorbent surface. The result depicts a threefold reduction in interaction energy (less negative value of ∆GTOT) after incorporating TiO 2 NPs, depicting stronger antibacterial properties. Lastly, adsorption column design using Bed depth service time (BDST), the Adams–Bohart and Thomas model fitting concludes the mass‐transfer‐controlled adsorption process and deploy the scalability of the process in a packed bed application.
ABSTRACT Despite leachate contamination being common around dumpsites, studies integrating spatial variation, soil‐depth profiles, groundwater quality, and associated environmental risks remain limited. This study assessed leachate, soil, and groundwater quality in the vicinity of a municipal solid‐waste dumpsite in Jaipur, India, using spatial sampling structured by distance, direction, and soil depth. Leachate was alkaline and reducing, with pH of 8.2–8.8, electrical conductivity (EC) of 25–29 mS cm −1 , total dissolved solids (TDS) of 12,460–16,000 mg L −1 , and detectable Cd, Cr, Cu, Pb, Ni, and Zn. Maximum soil EC and TDS values were higher at 0.3 m, whereas selected water‐extractable ions showed variable depth profiles. Groundwater pH ranged from 6.5 to 8.2, EC from 0.4 to 3.6 mS cm −1 , and TDS from 200 to 1770 mg L −1 . Borewells east of the study dumpsite showed the highest EC, TDS, and chloride concentrations. Spearman analysis showed depth‐specific soil associations and groundwater EC‐TDS‐chloride‐calcium co‐variation. Ecological‐risk assessment identified Cd as the principal soil‐risk driver, with moderate to considerable integrated ecological risk across the investigated soil profile. Soil non‐carcinogenic hazard indices were below 1 for adults and children, whereas groundwater‐ingestion hazard indices exceeded 1 at assessed locations, particularly for children, and were dominated by Cd. The absence of a consistent concentration decline with distance or depth indicates heterogeneous spatial and vertical variation. The single‐campaign spatial design did not confirm source attribution or transport pathways. Leachate treatment, runoff control, protection of groundwater‐use areas, and seasonal monitoring are recommended.
ABSTRACT Industrial effluents containing heavy metals, synthetic dyes, per‐ and polyfluoroalkyl substances (PFAS), pharmaceuticals, and endocrine‐disrupting compounds remain a major challenge for wastewater treatment. Conventional adsorbents, including activated carbon and zeolites, often show limitations in selectivity, regeneration, or adsorption capacity for complex wastewater systems. Polymer sorbents offer an alternative because their chemical structure and surface functionality can be tailored for specific separation and adsorption applications. This review examines studies published between 2021 and 2025, with particular attention to the relationship between polymer structure and adsorption performance. The discussion considers the effects of crosslinking density, pore architecture, and functional‐group modification on adsorption behavior across different classes of polymer sorbents. Representative examples include molecularly imprinted polymers for selective recognition, poly(ionic liquid)‐based materials for PFAS removal, stimuli‐responsive hydrogels with swelling‐dependent transport properties, and magnetic polymer nanocomposites that combine adsorption with straightforward separation. The review also discusses regeneration efficiency, structural stability during repeated adsorption–desorption cycles, and the balance between mechanical strength and biodegradability. Although substantial progress has been reported at the laboratory scale, pilot‐scale investigations and studies involving multi‐component wastewater remain relatively limited. Recent work applying machine learning to polymer design is briefly considered as a promising direction for accelerating material development. By bringing these aspects together, this review provides an updated overview of current polymer sorbent technologies and identifies priorities for future research and practical wastewater treatment applications, with the aim of supporting informed material‐selection decisions by treatment‐plant operators, regulators, and technology managers.
ABSTRACT Marine‐derived microplastic contamination has emerged as a growing food safety concern in artisanal sea salt production, where pollutants may become concentrated during solar evaporation and crystallization. In East Nusa Tenggara, Indonesia, traditional cooking salt often fails to meet edible‐grade standards because of elevated divalent mineral impurities and microplastic contamination. However, cost effective practical mitigation strategies for small scale producers remain very limited. This Study aimed to evaluate the effectiveness of three local natural filtration media, namely: Sugar palm fiber ( Arenga pinnata ), sea sand, and coconut shell charcoal used to filter brine prior to crystallization via boiling. A completely randomized design (CRD) framework was adopted, evaluating four distinct treatment conditions: a non‐filtered control (P0), sugar palm fiber filtration (P1), sea sand filtration (P2), and coconut shell charcoal filtration (P3). Physicochemical measurements and FTIR spectroscopy showed a significant difference in (p<0.05) the particle count and salt properties between the experiments. In terms of NaCl recovery and polymer reduction effectiveness, coconut shell charcoal filter (P3) gave the most satisfactory results. Using the SNI 4435:2017 Class 1 edible salt standard, P3 achieved an increase of NaCl purity from 84.14% to 94.62 % in addition to achieving the 41.78 % reduction of microplastics and the removal of 80.6% magnesium impurities and decreased the number of particles from 35 500 particles kg‐1 to 20 666 particles kg‐1. Fiber shaped particles and smaller than 100 µm particles were the most reduced particles after filtration. FTIR results revealed lower values of several polymer peaks in the filtered salt samples in comparison with the controlled ones. Under the experimental conditions evaluated, coconut shell charcoal filtration improved the physicochemical quality of artisanal salt and reduced microplastic contamination prior to crystallization.
ABSTRACT The accumulation of non‐biodegradable plastics is driving the search for environmentally friendly, low‐cost alternatives. This study investigated the production of biodegradable bioplastics using starch extracted from Ipomoea batatas and Manihot esculenta tubers. The tubers were pulverized, and starch was extracted. Bioplastic was produced by reacting the starch with ethanoic, methanoic, and propanoic acids in the presence of glycerol and water at 80°C for 25 min. The starch yield and the physicochemical, mechanical, and degradability properties of the bioplastics were determined. The results showed starch yields (57.5%; 52.26%), moisture content (12.38%; 13.74%), pH (6.9; 6.7), amylose content (20.4%; 20.67%) and amylopectin content (79.6%; 80.2%) for Ipomoea batatas and Manihot esculenta tubers, respectively. The mass of bioplastic produced was directly proportional to starch content and the number of carbon chains present in the organic acid. The mechanical properties showed that tensile strength was significantly ( p < 0.05) higher than that of the control, except for the 15 g bioplastic produced. Shear strength also showed a trend similar to tensile strength. The elongation/break properties significantly ( p < 0.05) increased in the methanoic acid‐derived bioplastic. The bioplastic degradation rates were (0.0059, 0.0056 and 0.0043 mg/ml/h) for Ipomoea batatas and (0.0099, 0.0098 and 0.0091 mg/ml/h) for Manihot esculenta‐derived biodegradable plastic, respectively , using Pseudomonas aeruginosa . The results of this study show that starches from Ipomoea batata and Manihot esculenta tubers could be a good source for bioplastic production because they are inexpensive, renewable, and readily biodegradable when disposed of in the environment.
