Reviews in Environmental Science and Bio/Technology最新文献

Civic development and industrial expansion have created opportunities but also accelerated environmental degradation. Bioremediation has emerged as a sustainable approach alongside biological and physicochemical methods to mitigate this decline. However, controlling the supply of electron donors and acceptors remains a challenge. Microbial electrochemical cells (MXCs) have emerged as a core component in bioelectronic technologies, utilizing electric current as an electron donor or acceptor. At the core of this technology is an electrogenic biofilm that serves as both the sensing and transducing element. This review examines the synergistic role of MXCs in bioremediation and real-time monitoring, highlighting how these biosensors, powered by microbial communities, uniquely combine pollutant detection with environmental bioremediation. It highlights recent advances, relevant studies, and the potential for advancing sustainable MXC-based approaches to contamination management. Emphasis is placed on the progress in biosensing applications in expanding the horizon for MXCs, particularly microbial fuel cells (MFCs) and microbial electrolysis cells (MECs). Lastly, the review deliberates on the barriers hindering the transition of technology and provides an outlook on future opportunities for MXC biosensors.

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Organic pollutants in soil pose a threat to ecosystems and human health. Abundant iron oxides with high biological activity readily undergo electron exchange with organic pollutants, thereby facilitating pollutant degradation and the remediation of organic contaminants in soil. Here, the research progress on iron oxide-mediated electron transfer processes in soil and their roles in promoting the degradation of organic pollutants is reviewed. First, the unique properties and functions of iron oxides are introduced. Subsequently, direct and indirect electron transfer processes facilitated by iron oxides in soil are described, including oxidative degradation, reductive degradation, and radical-mediated degradation of organic contaminants during iron transformation. Finally, the environmental implications of soil iron oxides are summarized, including enhancement of organic pollutant bioremediation, regulation of methane emissions, promotion of biogenic element cycling, and contributions to microbial electrochemical processes. Overall, understanding the behaviour of iron oxides could contribute to the development of more effective strategies for soil pollution remediation.

Phototrophic granules (or photogranules) are biological aggregates containing phototrophic and heterotrophic microorganisms. These organisms may engage in syntrophic interactions. In contrast to conventional activated sludge, photogranules keep carbon in the biomass through photosynthesis, leading to a higher potential for energy recovery. Photogranules are a candidate biomass for aeration-free wastewater treatment. About 10 years after the first description of photogranules, we review the emerging literature on this promising biomass and propose a unifying nomenclature, attempting to standardize terminology in the field of phototrophic aggregates. These efforts aim at making results in future publications more comparable. We critically discuss methods to assess the main performance indicators for successful photogranulation: settleability assessment, microbial activity and oxygen production. In a second part, characterization and monitoring methods of the physical properties of photogranule such as particle size distributions and microscopy are detailed. The review underscores the need for standardized and adapted methodologies to accurately describe photogranulation. The key factors to produce photogranules are investigated, focusing on the challenges of achieving a critical mass of relevant phototrophic microorganisms and providing the environmental conditions that favour photogranulation. The lack of consensus and data regarding several important parameters influencing photogranulation is highlighted and future research perspectives are indicated. Achieving and maintaining the performance of a photogranule-based process at larger scales will require a deeper understanding of the phenomena leading to photogranulation. Understanding photogranule formation is the first step towards a more sustainable wastewater treatment technology.

Phosphorus is a key topic in sustainable development due to its extreme importance for sectors like agricultural production and the chemical industry. Currently, the main phosphorus source is an ore called phosphate rock, a non-renewable resource whose mining contributes to geopolitical issues and environmental concerns. Phosphorus recovery arises as a technology that can provide a new phosphorus source and avoid environmental problems associated with the phosphorus excess in waterbodies. Among the main methods available, chemical and, particularly, electrochemical methods are promising due to their unique advantages. This paper presents a general review of chemical and electrochemical technologies developed to recover phosphorus from wastewater. An overview of the fundamental aspects of these technologies is provided, as well as updated information on their application to industrial effluents. The effect of the main process variables on the phosphorus recovery effectiveness is discussed, and a critical analysis of the prime benefits and drawbacks of its application is made.

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Cementations bind sand/soil particles via physical and chemical interactions to form composite solids with macroscopic mechanical properties. While conventional cementation processes (e.g., silicate cement production, phosphate adhesive synthesis, and lime calcination) remain energy-intensive, bio-cementation based on ureolytic microbially induced carbonate precipitation (UMICP) has emerged as an environmentally sustainable alternative. This microbial-mediated approach demonstrates comparable engineering performance to traditional methods while significantly reducing carbon footprint, positioning it as a promising green technology for construction applications. Nevertheless, three critical challenges hinder its practical implementation: (1) suboptimal cementation efficiency, (2) uneven particle consolidation, and (3) ammonia byproduct emissions during ureolysis. To address these limitations, strategic intervention in the UMICP process through polymer integration has shown particular promise. This review systematically examines polymer-assisted UMICP (P-UMICP) technology, focusing on three key enhancement mechanisms: First, functional polymers boost microbial mineralization efficacy through multifunctional roles, namely microbial encapsulation for improved survivability, calcium carbonate nucleation site provision, and intercrystalline bonding via nanoscale mortar effects. Second, polymeric matrices enable homogeneous microbial distribution within cementitious media, facilitating uniform bio-consolidation throughout treated specimens. Third, selected polymer architectures demonstrate ammonium adsorption capabilities through ion-exchange mechanisms, effectively mitigating ammonia volatilization during urea hydrolysis. Current applications of P-UMICP span diverse engineering domains, including but not limited to crack repair, bio-brick fabrication, recycled brick aggregates utilization, soil stabilization, and coastal erosion protection. The synergistic combination of microbial cementation with polymeric materials overcomes the inherent limitations of pure UMICP systems and opens new possibilities for developing next-generation sustainable construction materials.

This review focuses on the degradation processes of elastomers, primarily concerning natural and synthetic rubber. The thermal, mechanical, and physical degradation processes are explained in general terms. The chemical (depolymerization by metathesis) and biological (biodegradation) processes are discussed in more detail, and degradation mechanisms are proposed. The future of biotechnology offers promising opportunities to revalorize both natural rubber and synthetic elastomers through the recovery of biodegradation products. Metathesis depolymerization is attractive not only from the perspective of green chemistry but also from the viewpoint of circularity, as it leads to more efficient, user-friendly, and environmentally friendly reactions. This review addresses rubber waste management, the life cycle of elastomers, and recycling. The circular economy and sustainability in elastomers are discussed, and we propose a scoring of the environmental impacts of elastomer degradation processes. Biological treatments yield the best results regarding the impacts generated, with the second-best and third-best options being chemical depolymerization by metathesis and mechanical processes. Pyrolysis is the least recommended option as it requires high process temperatures, long reaction times, and high energy consumption, with increased greenhouse gas emission generation, and involves high economic and environmental costs. These processes can be used individually or in combination to reuse, recycle, or recover elastomer waste for energy and support the 4R framework's goals of reducing, reusing, recycling, and recovery, presenting significant opportunities for sustainable waste management.

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Microbial conversion of cheap and problematic carbon sources, like CO₂ and CO, into fine chemicals offers a promising green alternative to numerous traditionally fossil fuel-based industries such as steel, cement, and pharmaceuticals production. Purple phototrophic bacteria (PPB) are emerging as versatile key players in carbon–neutral systems due to their anoxygenic photosynthesis and diverse metabolic capabilities, enabling the transformation of carbon and nutrients into a wide range of valuable products. Traditionally positioned to treat organic carbon and produce medium-value products like bioplastics and biomass, PPB also exhibit autotrophic capabilities, enabling the valorization of waste gases, such as CO₂ and CO. A key strength of PPB is their metabolic and ecological diversity, including species inhabiting saline environments. Halophilic bacteria are known producers of valuable chemicals for pharmaceutical and medical applications, such as osmolytes (ectoine, hydroxyectoine), pigments, amino acids (proline) and natural coenzymes (ubiquinone), yet halophilic PPB remain underexplored in green upcycling processes. This study identified halophilic PPB capable of transforming waste gases into health and wellness products. Through a comprehensive literature review, we compiled a list of halophilic PPB and mined their genomes for genes linked to CO₂/CO utilization as carbon sources. Further genomic search revealed genes encoding enzymes for ectoine/hydroxyectoine, proline, ubiquinone, and carotenoids (lycopene, β-carotene, spirilloxanthin, and spheroidene). We identified 276 genomes of PPB with the genomic potential to valorise CO₂/CO into health-promoting ingredients, highlighting 22 species capable of producing three or more chemicals simultaneously. These findings highlight the untapped potential of halophilic PPB as bio-platforms for sustainable pharmaceutical production.

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Membrane filtration technologies play a crucial role in water and wastewater treatment due to their high efficiency in removing diverse pollutants, including metal traces, organic compounds, pharmaceuticals and microorganisms. However, conventional membranes suffer from significant limitations, such as fouling, limited chemical resistance, and low mechanical strength, which hinder their long-term performance and economic viability. Addressing these challenges is critical for advancing water/wastewater treatment technologies. This study explores the transformative potential of integrating advanced nanomaterials (NMs) into membrane structures to enhance their efficiency, durability and pollutant removal capabilities. NMs such as ZnO, TiO₂, Fe₂O₃, CuO, SiO₂, GO, and MOFs are selected for their exceptional properties, including high surface area, strong adsorption capacity, catalytic activity, mechanical robustness, and antibacterial effects. This review provides a comprehensive analysis of the latest advancements in NMs-enhanced membranes, focusing on different types of NMs, incorporation strategies, and associated challenges. Additionally, it examines the impact of NMs on microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), and Reverse osmosis (RO) membranes, assessing improvements in surface morphology, physicochemical properties, and overall filtration performance. By critically evaluating the benefits and limitations of these hybrid systems, this study highlights their potential to revolutionize water treatment through sustainable and cost-effective solutions. Finally, future perspectives and research directions are discussed to further advance this innovative approach in addressing global water quality challenges.

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Per- and polyfluoroalkyl substances (PFAS) are highly persistent organic pollutants due to their strong C–F bonds, which contribute to their environmental persistence and associated health risks. Naturally-occurring microbes have the ability to degrade PFAS, with Pseudomonas genus showing the highest efficiency, including Pseudomonas plecoglossicida (75%) and Pseudomonas aeruginosa (67%), which has received much attention. This review explores the underlying mechanisms during microbial PFAS degradation, emphasizing bond cleavage processes, including C–F and C–Cl bonds, and the critical roles of microbial enzymes. Microorganisms utilize specialized metabolic strategies to actively cleave chemical bonds within PFAS molecules, initiating their breakdown. Additionally, microorganisms secrete specific enzymes, which play pivotal roles in catalyzing PFAS degradation. Microorganisms and their enzymes can transform and/or defluorinate PFAS through different metabolic processes, improving the efficiency of PFAS degradation. This review further explores the current challenges in PFAS biodegradation and outlines future research directions, aiming to help future studies overcome these obstacles and drive progress in this field.

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Microcystin, a potent cyanobacterial toxin, poses a potential health risk to humans through exposure to recycled water used for food crop irrigation. This comprehensive review synthesizes current knowledge on microcystin uptake and accumulation in various food crops, assessing associated health risks based on reported toxin levels and tolerable daily intake values. The impact of wastewater irrigation on microcystin uptake is also evaluated. Our analysis reveals critical knowledge gaps, highlighting key research priorities for ensuring food safety and mitigating human exposure to microcystin. Future studies should address these gaps to inform evidence-based guidelines for safe recycled water use in agriculture.