Central Pollution Control Board

The biological reduction of N2O to N2 relies on N2O-reducing bacteria (N2ORB), which involves enhancement of the N2O-reducing enzyme (N2OR) and selection of N2ORB. This study investigates the short-term effects of microoxic pretreatment on N2OR and long-term operational strategies for wastewater treatment aimed at achieving N2O mitigation. In denitrification batch experiments, microoxic pretreatment (with dissolved oxygen (DO) at 0.2 mg/L for 2 h) enhanced N2OR levels to 1.27 times that of the control group, resulting in a 35% to 65% reduction in N2O emission flux. Through long-term reactor operation (294 days), controlling the microoxic environment during the oxic stage revealed that the second anoxic stages of the anoxic/oxic/anoxic (AOA) or anoxic/oxic/anoxic/oxic (AOAO) processes emitted no N2O. Isotope analysis confirmed a high N2O reduction ratio of 90.46%. The coexpression of nosZ with cytochrome c oxidase and CRP/FNR transcriptional regulators in clade I N2ORB reflects the metabolic versatility of denitrifiers, driven by the integrated environmental selection of long-term microoxic conditions in oxic stages coupled with step-feeding strategies in anoxic stages. These findings highlight the AOA and AOAO processes under such controls as effective strategies for achieving both efficient nitrogen removal and N2O mitigation.

Methane, recognized as a crucial clean energy source and the second-most significant greenhouse gas following carbon dioxide, possesses a high global warming potential. Catalytic combustion serves as a primary method for lean methane mitigation. In recent years, palladium-based zeolite catalysts for methane oxidation have attracted extensive attention due to their high activity and stability. In this paper, the active sites, reaction mechanisms, and precise control strategy of Pd species in Pd/zeolite catalysts for the complete oxidation of methane are reviewed. First, the review outlines the active sites and reaction pathways for the lean methane combustion reaction on Pd/zeolite catalysts. Next, we discuss how these palladium active sites can be modulated through zeolite support engineering. Additionally, the review summarizes the precise construction and stabilization strategies for palladium active sites. We hope that this review will serve as a roadmap for the development of next-generation Pd/zeolite methane oxidation catalysts with high reactivity, antisintering, and antipoisoning capabilities.

Since the discovery of graphene in 2004, two-dimensional (2D) photoactive materials have gained significant attention owing to their exceptional thermal, electrical, and mechanical properties, as well as their high specific surface area and tunable electronic structure. While photocatalysis remains a promising approach for the degradation of persistent contaminants (PCs), recent advances in materials science have shifted the focus toward 2D material-based heterojunction systems. These systems exhibit abundant reactive sites, enhanced charge transport and separation efficiencies, and robust redox capabilities. This review comprehensively highlights major breakthroughs in 2D metal oxides, transition metal dichalcogenides, metal-free photocatalysts, and MXene-derived heterojunction architectures that demonstrate strong potential for PC detoxification. Furthermore, herein emerging green synthesis strategies that introduce a new dimension to 2D material production, emphasizing the growing use of waste-derived precursors to achieve environmentally benign fabrication, are outlined. Notably, these routes offer dual advantages by lowering production costs and reducing reliance on hazardous chemicals. The article concludes with an integrated perspective on present challenges and future opportunities for 2D heterojunction systems within a circular engineering framework. Finally, the recent progress and commercialization pathways for deploying circularity engineered 2D material-based photocatalytic technologies as sustainable advanced oxidation systems for the effective remediation of PCs are elaborated in detail.

Ecological restoration tightly winds urbanization, industrialization, and unsustainable tourism against the urgency of denoting innovative solutions for the same and converging its only imaginary and possible path along sustainable development. This study thus wants to put forward a new framework for synergizing eco-tourism and phytoremediation for waste management, ecological restorative performance, and conservation. The proposed analysis empirically assesses the effectiveness of plant-based phytoremediation in contaminated sites through machine learning techniques in aiding complementing eco-tourism in the establishment of an ecologically functional yet economically viable green landscape. Real-world datasets were analyzed against soil heavy metal concentrations, water quality indices, and tourism activity metrics through supervised and unsupervised machine learning models such as Random Forest and Support Vector Machines and K-means clustering. The findings conclude that ML models are capable of predicting and optimizing the efficiency of phytoremediation, as well as their potential to accomplish integration with eco-tourism and environmental conservation, driven by data strategy. This contributes to a sustainable framework from the policymakers' view, conservationist, and development of tourism.

Antimicrobial resistance (AMR) represents a critical public health challenge, with surface waters serving as reservoirs for antibiotic-resistant bacteria (ARB). Among these, gram-negative enteric bacteria (GNEB) are recognized as major carriers of resistance genes and frequent causes of human infections. As a major tourism destination in Thailand, Phuket Province is likely to face increasing AMR-related issues. This study investigates water quality and the prevalence of ARB in the Bang Yai Canal, a key urban waterway in Phuket, and its transition into Phuket Bay. Water samples were collected from nine stations during the dry and rainy seasons of 2024. Total heterotrophic bacterial counts and GNEB resistant to amoxicillin, tetracycline, norfloxacin, and meropenem were examined in relation to water quality parameters. Results revealed significant spatial variation, with urban areas contributing substantially to ARB prevalence. Amoxicillin-resistant bacteria were the most prevalent, particularly among GNEB, while meropenem-resistant bacteria were consistently detected at most stations despite their low abundance. Seasonal variations indicated higher bacterial abundance upstream during the dry season and downstream during the rainy season, potentially driven by tourism and runoff dynamics. The coastal station exhibited a notably high proportion of antibiotic-resistant marine heterotrophic bacteria. Redundancy analysis identified turbidity and dissolved oxygen as significant factors influencing bacterial counts. Cluster analysis grouped stations based on water quality, with upstream and coastal sites exhibiting distinct profiles. This study underscores the critical role of urban activities in ARB dissemination and highlights the environmental and public health implications of ARB in coastal ecosystems, necessitating targeted mitigation and monitoring strategies.

ABSTRACTTransparent wood composite (TWC) is an emerging material with a wide range of promising applications in energy‐efficient systems. In recent years, research interest in TWC has grown significantly, with numerous studies focusing on its application‐oriented variants. These efforts often involve incorporating specific components to enhance desirable properties. Apart from optical properties, due considerations have been given to the specialized features of TWC, including flexibility, anisotropy, fire/flame retardancy, thickness, mechanical strength, photoluminescence, thermochromism, photochromism, IR and UV shielding, and energy storage and conservation capabilities. The process of modifying wood to prepare a mechanically stable cellulose framework is still under the process of refinement. A diverse range of polymers has been studied for infiltration to achieve targeted characteristics for the resultant TWC for specific applications. Functionalization of TWC has significantly widened its scope of utilization in the development of multifunctional bio‐based materials. As a biocompatible and sustainable material, TWC offers enormous potential for further development. This review provides a comprehensive assessment of recent advances and prospects in TWC research, with an emphasis on identifying key research gaps and opportunities for development in this rapidly evolving field.

Water quality analysis of samples from regions of northeastern parts of India affected by the problem of acidic mine discharge (AMD) revealed high concentrations of aluminum, sulfate, and iron. AMD water in the region is a suitable candidate for insitu ettringite precipitation, serving as a motivation behind the current research. The study explores the effectiveness of integrated nanofiltration (NF), and insitu ettringite (hydrous calcium aluminum sulfate) precipitation for remediation of acid mine drainage (AMD), targeting key contaminants: sulfate, iron, and aluminum. Stagewise chemical precipitation, optimized by precise pH control and reagent dosing, combined with cross-flow nanofiltration in the downstream, demonstrated over 90% contaminant removal efficiency. The presence of aluminum ions was found to have a synergistic effect on sulfate removal, leading to enhanced contaminant removal. NF membranes, integrated into the treatment process were able to remove sulfate concentrations to less than 10 mg/L. Ettringite precipitation were carried out by pH modification. XRD peaks demonstrated crystalline ettringite formation at a precise pH range of 11.5-12.5. Insitu ettringite precipitation showed promise as a sustainable remediation strategy, encapsulating contaminants within a stable crystalline structure and achieving 90% aluminum reduction. This integrated remediation technique not only simplifies the treatment methodology but also offers a comprehensive solution for AMD treatment compared to standalone techniques.