Due to the frequent occurrence of extreme weather and severe environmental pollution, food security and human survival are at risk. Silicon, a key element in plant nutrition and environmental remediation, has a variety of applications in combatting various forms of abiotic and biotic stress and fostering healthy plants and soils. To establish a silicon-based defense barrier for plants, we firstly summarized and grouped the mechanisms of silicon functioning in plants: 1) molecular regulation and overall strengthening, 2) physical barrier and apoplastic obstruction, and 3) energy conservation. Additionally, the types and applications of silicon-based materials as soil remediation materials and fertilizers were discussed. Then, the challenges to build up such a barrier were analyzed in terms of silicon absorption and transportation, deposition and aggregation, and perception and regulation. An "external + internal" strategy was proposed to accelerate the establishment of a silicon-based barrier to enhance plants’ resistance to extreme weather and environmental pollution, including high temperatures, drought, ultraviolet radiation, salt, heavy metals, nutrient deficiencies, new pollutants, and biotic stress. Finally, this paper emphasized the contribution of silicon barrier to healthy Soil-Plant-Atmosphere system that eventually benefit human health. This paper highlights the current understanding and future perspectives of silicon-related research in Soil-Plant-Atmosphere system, providing a reference for the application of silicon-based materials in environmental and agricultural fields.

Given the widespread use as flame retardants, plasticizers, and organophosphate esters (OPEs) received increasing scientific interests on their occurrence and ecotoxicological research progress. This review comprehensively conducted bibliometric analysis and surveyed the OPEs occurrence in aquatic ecosystem (water, sediment, and aquatic organisms) and human-related (drinking water and sewage) over the past decade to unraveling knowledge gaps. The OPEs concentrations in water, sediment were at the range of not detected (n.d.) or several to hundreds ng/g or ng/L and exhibited landuses-specific characteristics. The electronic waste (e-waste) processing activities and sewage discharge were identified as point sources of OPEs in aquatic environment. Emission source intensity, water chemistry, and content of organic carbon were important for the partition and transfer processes of OPEs in the water, as well as hydrophobicity of OPEs dominating the absorption on the organic matter. Degradation, especially photodegradation and reductive degradation, has application potential in improving removal efficiencies of chlorinated-OPEs (Cl-OPEs) being reluctant to degrade. Generally, most surveyed OPEs have negligible ecological and health risks, whereas those OPEs with moderate threats or chronic effects on aquatic ecosystem should gain more attention. This review elucidates the status of OPEs pollution in water and highlights the need for more transport and degradation studies on traditional and emerging OPEs and metabolites to further identify potential threats on aquatic ecosystem.

The addition of fresh substrates can alter the decomposition of the native soil organic matter, referred to as the priming effect (PE). It is a crucial process within the cycling of soil organic carbon (C) and believed to be regulated by nitrogen (N) input. However, the direction and magnitude of this N effect on the PE are complex due to the involvement of various factors following N addition into the soil. This review synthesizes the key factors driving the responses of the PE to N addition from the perspective of C-substrate quantity and quality, N addition rates and forms, soil properties including organic C stability, N availability, electrical conductivity, pH and pH buffer capacity. The temporal change in the N effect on the PE is also discussed. In studies observing a suppressive effect of N addition on the PE, the role of N addition in directly suppressing microbial community metabolism (e.g., osmotic stress and low pH) has been largely ignored. We propose the application of multi-omics techniques to examine the relationship between microbial functional traits and soil C cycling through the PE and its response to N addition, as well as the application of spatial omics and imaging techniques in exploring the connection between in-situ soil C distribution and the PE and its response to N addition. Such studies can potentially elucidate how elevated atmospheric CO2 may affect the PE and thus soil C stock via increasing plant C input and regulating nutrients sources for plant uptake under N inputs.

Di-iso-nonyl phthalate (DINP) and di-iso-decyl phthalate (DIDP) have been employed increasingly as plasticizers to replace di-(2-ethylhexyl) phthalate (DEHP), a hormonal disruptor. Through this systematic review, we reviewed their (1) contamination levels in the environmental media, foods, and consumer products, (2) human exposure levels in national biomonitoring studies, and (3) associations with human sex and thyroid hormone disruption. PubMed, Scopus, and Web of Science were searched and eligible studies were identified. DINP and DIDP were found at higher concentrations in indoor environments, especially with high human activity and PVC use. In foods, contamination levels vary by production methods and tend to be higher in fatty foods. In children’s products, both plasticizers were more highly detected in samples measured before 2010. National biomonitoring data from several countries demonstrated that urinary levels of DINP and DIDP metabolites were relatively lower than those of DEHP. However, exposure to DINP has been associated with anti-androgenic potential in male offspring and adults and decreased thyroid hormones in mother–child pairs. In conclusion, existing literatures demonstrated widespread occurrence of DINP and DIDP in the indoor environment, diet, and children’s products, and in the human populations worldwide. At the current levels of exposure, DINP exhibited endocrine disruption potentials similar to those of DEHP, especially among males and pregnant women. Knowledge gaps in DIDP exposure among the human population were identified and should be considered for future studies.

Diatoms have unique silica cellular and metabolic characteristics and can grow in various environments, including wastewater, facilitating pollutant removal. Diatoms provide a sustainable solution to municipal wastewater treatment, particularly in the tertiary and quaternary stages, contributing to carbon neutrality. Diatom-based materials (such as diatom biomass) have wide applications and can be processed into value-added bioproducts such as lipids, polysaccharides, and pigments. Despite their potentials, the applications of diatoms in wastewater treatment are limited. Existing reviews fail to address how diatom growth kinetics affects wastewater treatment. Here, we for the first time summarize diatom growth kinetics and propose promising species for municipal wastewater treatment. Given the scarcity of reviews on diatom performance in wastewater treatment, we also discuss the efficacy of diatoms in removing contaminants from municipal wastewater. Moreover, we elucidate the removal mechanisms of nutrients, heavy metals, and emerging contaminants by diatoms that are missing in existing reviews. Considering the complexity of wastewater, we emphasize selecting diatom species with high growth rates, tolerance to contaminants, efficient nutrient removal/uptake, and COD removal, and bioproduct yields. This will ensure both effective treatment and economic viability. In addition, we discuss the value of diatom frustules and bioproducts generated from wastewater. Lastly, we highlight future directions including promoting diatom growth, exploring diatom-dominated consortia in wastewater treatment, and evaluating the values of diatom biomass cultivated in wastewater. This review examines the potential and applications of diatoms in municipal wastewater treatment, especially effluent polishing.

Plastic debris (including macro-plastics, microplastics (MPs), and nanoplastics), defined as an emerging contaminant, has been proven to significantly affect soil ecosystem functioning. Accordingly, there is an urgent need to robustly quantify the pollution situation and potential sources of plastics in soils. China as the leading producer and user of agricultural plastics is analyzed as a typical case study to highlight the current situation of farmland macro-plastics and MPs. Our study summarized information on the occurrence and abundance of macro-plastics and MPs in Chinese farmland soils for the first time based on 163 publications with 728 sample sites. The results showed that the average concentration of macro-plastics, and the abundance of MPs in Chinese farmlands were 103 kg ha−1 and 4537 items kg−1 (dry soil), respectively. In addition, this study synthesized the latest scientific evidence on sources of macro-plastics and MPs in farmland soils. Agricultural plastic films and organic wastes are the most reported sources, indicating that they contribute significantly to plastic debris in agricultural soils. Furthermore, the modeling methods for quantifying macro-plastics and MPs in soils and estimating the stock and flow of plastic materials within agricultural systems were also summarized.

Machine learning (ML) models are widely used methods for analyzing data from sensors and satellites to monitor climate change, predict natural disasters, and protect wildlife. However, the application of these technologies for monitoring and managing algal blooms in freshwater environments is relatively new and novel. The commonly used models in algal blooms (ABS) so far are artificial neural networks (ANN), random forests (RF), support vector machine (SVM), data-driven modeling, and long short-term memory (LSTM). In the past, researchers have mostly worked on predicting the effluent parameters, nutrients, microculture, area and weather conditions, meteorological factors, ground waters, energy optimization, and metallic substances in algal blooms using ML models. Most of the studies have employed performance metrics like root mean squared error, mean squared error, peak signal, precision, and determination coefficient as their primary model performance measures for accuracy analysis, and the usage of transfer, and activation function. While there have been some studies on this topic, several research gaps are still to be addressed. The most significant gaps are related to the limited application of ML in different algae bloom scenarios, the interpretability of ML models, and the lack of integration with existing monitoring systems. Keeping these in mind, this review article has been methodically arranged to present an overview of the past studies, their limitations, and the way forward toward the application of ML in the prediction of ABS, thus benefitting future researchers in this area. This review aims to summarize the data that are available, including some benchmarking values. Highlights Real-time monitoring of dynamics using ML is essential for mitigating algal blooms. Various complexities hinder applications of current ML algorithms in ABS. Activation and transfer functions can be used for selection of ML to predict ABS. Integrated ML algorithms can drive feature engineering to predict and control ABS.

Microplastics (MPs) are emerging contaminants that adversely affect environmental health. In this review, we discuss the uptake of MPs by plants via endocytosis and crack-entry pathways in the roots and stomata of leaves; the translocation of MPs via xylem and phloem; and the toxicity of MPs to diverse plant species through oxidative stress, inhibition of photosynthesis, cytotoxicity, and genotoxicity. It’s difficult to assess the health risks of MPs because they directly cause toxicity and also change soil properties and the bioavailability of coexisting pollutants, such as plastic additives, in the plant rhizosphere, and bioaccumulate along the food chain. Moreover, compared to the uptake behavior and phytotoxicity effects of MPs in laboratory and hydroponic studies, MPs of various shapes, sizes, and types are likely to cause different effects on plants in complex natural environments. This review proposes potential phytoremediation strategies, including phytoextraction, immobilization, and rhizoremediation, for MP pollutants and provides guidelines for the bioremediation of MP-contaminated environments to enhance environmental sustainability. In the phytoremediation of MP pollution, the selection and disposal of plants used for phytoremediation and the optimization of functional microbes in the rhizosphere remain challenging. Future studies should address knowledge gaps in (i) methods for determining environmentally-relevant concentrations of MPs, (ii) the assessment of the ecological and human health risks of MPs in the natural environment, and (iii) the development of effective strategies for the phytoremediation of MP pollution.

The outbreak of the novel coronavirus lasted from 2019 into 2023 and the number of patients infected with the virus is still on the rise, greatly impacting people’s daily lives and the environment. Research on metal nanoparticles has developed rapidly during virus outbreaks. There have been review articles summarizing the important role of nanomaterials in the prevention, diagnosis, and treatment of viruses, because they have antimicrobial properties or can be used as drug carriers. However, the widespread application of metal nanoparticles is not yet mature, and there are many cases of abuse, which inevitably produce health and environmental risks. The aim of this review is to highlight the potential health and environmental risks of metal nanoparticles under the COVID-19 pandemic, to propose corresponding strategies to address them, and to point out promising research directions in future. Some metal nanoparticles exposed to organisms and the environment may incur bioaccumulation effects and direct toxicity. Toxicity can be reduced by changing the surface properties of metal nanoparticles, and the accumulation of metal nanoparticles in plants can be used for recycling and regeneration. More importantly, those papers related to life cycle assessment of metal nanoparticles tend to ignore their synthesis and regeneration processes. This paper believes that the production process of metal nanoparticles has a large environmental risk while the end-of-life process is often neglected. We conclude that the synthetic method can be optimized from the green synthesis of metal nanoparticles. Furthermore, additional attention can be paid to the recovery and regeneration of metal nanoparticles to promote the green use of metal nanoparticles and finally reduce pressure on the environment.

Foliage uptake of atmospheric elemental mercury (Hg0) and subsequent translocation by the phloem is the main pathway for Hg accumulation in tree rings. Tree rings have been used as the emerging natural archive to directly reconstruct centennial trends of atmospheric Hg0 level. The tree-ring Hg records in remote regions have successfully reconstructed the peak of anthropogenic Hg emissions in Europe and North America in 1960s − 1970s and the distinct increase of Hg emissions in Asia since 1980s. Combining the Hg concentrations and isotopic signatures would provide historical atmospheric Hg trends and Hg emission source shifts. The mechanisms for Hg translocation, specifically the radial translocation and impacts of environmental and tree physiological factors, are yet to be clarified to explain the nonlinear relation between atmospheric Hg0 concentration and Hg signals in tree rings. Thus, we recommend to trace Hg accumulation and translocation processes and their Hg isotopic fractionation in tree rings, and examine the relationship between tree-ring Hg profile and atmospheric pollution level in specific tree species. Finally, we suggest to develop more statistical models to quantify environmental and tree physiological impacts on Hg accumulation and translocation in tree rings.