Nagarathnam Rajesh

MoO ₃ -modified carbonised PET waste bottles for oxidation coupled adsorptive desulfurization.

Autism spectrum disorder (ASD), a complex neurological condition, is characterized by challenges in communication, behavior, and social interaction. ASD is often accompanied by food selectivity, gastrointestinal problems, and micronutrient imbalances, which have led to growing interest in dietary interventions as adjuncts to management. However, the available approaches remain conceptually fragmented and understudied. This narrative review synthesizes evidence on 21 dietary interventions, organizing them within a reduction-addition-substitution-elimination (RASE) framework together with an evidence-maturity and clinical impact map. Overall, ketogenic diet, balanced essential fatty acids, probiotics/prebiotics, and gluten-free/gluten-free casein-free approaches have accumulated comparatively more studies than other diets, whereas several others remain supported mainly by theoretical or limited evidence. Across interventions, small samples, heterogeneous study designs, limited controlled trials, and practical barriers, such as dietary complexity and caregiver burden, constrain firm conclusions. This Review provides an integrated reference for clinicians, researchers, and caregivers and identifies priorities for future research.

Fermentation enhances the nutritional properties of foods. Fermented water of Kerala red rice (Oryza sativa L. subsp. indica), traditionally consumed in South India remains underexplored scientifically. This study characterizes the nutritional, microbial, and metabolite profiles of Kerala red rice water (broth) after 18 hours of natural fermentation using biochemical assays, shotgun whole-genome metagenomic sequencing (Illumina NovaSeq X Plus), untargeted gas chromatography-mass spectrometry (GC-MS) metabolomics, and a phytase-mediated mineral release assay. Fermentation enhanced nutritional quality with increase in carbohydrates by 22.7%, protein by 163.52%, and free amino acids by 35.47% compared to unfermented controls. Phytase activity rose from negligible levels to 0.12 U mL⁻¹. Metagenomics identified 50 taxa, dominated by Proteobacteria (59.63%) and Firmicutes (40.12%), with ∼34% of the community carrying phytase-encoding genes. Dominant genera included Pantoea, Saccharibacillus, and Bacillus. Fermentation also enhanced mineral release, with calcium, iron, and zinc in the fermented rice water showing increases of approximately 1190%, 566%, and 93%, respectively, relative to unfermented controls over a 360 min in vitro digestion period. These findings provide the first integrated insight bridging traditional dietary practice with modern analytical science.

The discharge of surplus phosphate in water results in eutrophication, thereby reducing dissolved oxygen and threatening aquatic ecosystems. This study focuses on the synthesis of a novel sustainable microbe-biopolymer composite (BS) through a facile method using zirconium impregnated cellulose (CZ) and Saccharomyces cerevisiae for phosphate adsorption. Both the BS and CZ were characterized through FT-IR, BET, XRF, TGA, SEM-EDX, XRD, and X-ray photoelectron spectroscopy analysis. The adsorption was effective over a wide range of pH (2.0–9.0), and the mesoporous adsorbent (BS) involving the synergistic effect of immobilization significantly enhances the adsorption efficiency from 60 to 95%. The maximum adsorption capacity was also enhanced from 22.11 to 34.23 mg·g^–1. The adsorption process is spontaneous and endothermic and follows pseudo-second-order kinetics. Cyclic network modeling provides insight into the interaction of phosphate with zirconium and the functional groups on the microbe surface. The BS material is stable up to four cycles of regeneration, and the phosphate is recovered as its sodium salt.

The toxicity of heavy metals, particularly lead, in water is a significant environmental and health concern. Carbonaceous adsorbent materials derived from waste sources exhibit promising potential for sequestering toxic metals from water. Herein, we developed a sustainable approach using valorised waste polyethene terephthalate (PET) obtained from plastic bottles as a carbonaceous adsorbent material via microwave assistance and functionalized it with L-cysteine to incorporate surface functionalities for effective coordination with lead ions. The adsorbent was further encapsulated using a sodium alginate matrix to form a hydrogel, which increased the adsorption capacity and enabled scaling up. Analytical surface characterisations, including FE-SEM, EDS, BET, TGA, XPS, XRF, FT-IR spectroscopy, and PXRD, were performed to study the adsorbent. The maximum adsorption capacity under optimised conditions was found to be 370.84 mg g⁻¹. Kinetic studies revealed that the system follows a pseudo-second-order model, and thermodynamic analysis showed that adsorption is spontaneous and exothermic in nature. The interaction of lead ions with the surface of the adsorbent was further corroborated using molecular dynamics (MD) simulations. The prepared adsorbent was tested in tap water and drinking water, and the adsorbent material exhibited 86.04% and 90.00% removal of lead, respectively. Lead was successfully desorbed using 0.1 M NaOH. In addition to supporting sustainable waste management, this work presents a relatively low-cost, eco-friendly adsorbent system that can serve practical utility in real-world applications for the remediation of lead-contaminated water.

Lithium, often referred to as ‘white gold,’ is a vital element in modern technology, and its applications are found in various fields, including Li-ion batteries (LIBs). Being explored for countless technological applications, lithium recovery from spent batteries is a significant concern. In this study, we report a titanium nanorod-based adsorbent modified with PEI for the adsorptive removal of lithium from various sources. The hydrothermally synthesized adsorbent was mesoporous, with a specific surface area of 45.8 m² g⁻¹. The characteristics of the adsorbent material were corroborated using multiple analytical techniques such as BET-N₂ isotherm analysis, XPS, PXRD, TGA, FESEM-EDS, FTIR, and DLS. The maximum adsorption capacity of the material under optimized conditions was 2.76 mg g⁻¹. The adsorption process was endothermic and feasible, fitting well with the Langmuir isotherm following pseudo-first-order kinetics. The spent adsorbent was recovered and exhibited a regeneration capacity of up to 4 cycles. Furthermore, desorbed lithium was successfully converted into Li₂O, contributing to a circular economy.

Sequestration of uranium from water requires the development of effective materials coupled with an innovative and sustainable approach. In this regard, we propose an inventive design of an adsorbent material involving microplastic-microbe synergy. The non-pathogenic microbe Saccharomyces cerevisiae was immobilized on polymethylmethacrylate (PMMA), a widely used thermoplastic. PMMA in its pure form and acrylic microplastic waste were used separately to synthesize biosorbents for the removal of uranium. The active functional groups on the yeast cell wall embedded in the acrylic plastic ensured effective binding of the metal on the biosorbent. The detailed results from SEM-EDAX, TGA, XPS, FTIR, and BET analysis of the biosorbent elucidated our understanding of the mechanistic interactions involved in the adsorption process. The Langmuir maximum adsorption capacities obtained for the biosorbents from pure PMMA and acrylic microplastic were 200 and 197 mg g⁻¹, respectively, at pH 5.0. The selectivity, regeneration, and application studies suggest that these biosorbents are versatile waste-to-value materials useful for environmental remediation in alignment with UN Sustainable Development Goals 2030.

Impact of climate change that stems from gaseous emissions require sustainable materials to eliminate sulfur. This study involves the modification of humic acid with magnetite nanoparticles (Fe₃O₄ NPs) by a microwave‐assisted synthesis of an absorbent with reasonable pore volume and diameter for elimination of thiophenic compounds from fuel. The magnetic nano adsorbent designated Fe ₃ O ₄ @HA was characterized using advanced spectroscopic techniques, while their structure and morphology were analyzed through DLS, XPS, XRD, FT‐IR, TGA, FESEM‐EDX, VSM, and BET‐N ₂ techniques. These findings indicated that the synthesized magnetic nano adsorbent (Fe ₃ O ₄ @HA) has appropriate oxygen functionalities with a specific surface area of 335 m ² g ⁻¹ and a mesoporous structure with a pore diameter of 9 nm. The adsorption capacity for sulfur was determined to be 62.73 mg g ⁻¹ . The kinetic and isotherm models, coupled with thermodynamic characteristics, confirmed that the adsorption of sulfur onto the adsorbent was spontaneous, exothermic, and followed pseudo‐first‐order kinetics. The adsorbent material demonstrated reusability for sulfur adsorption for up to six cycles. The economic and environmental advantages of the preparation process provide humic acid modified with magnetite nanoparticles (Fe₃O₄ NPs) as an interesting candidate for real‐world applications.