Reviews in Environmental Science and Bio/Technology最新文献

Biochar is a carbon-rich material produced through the pyrolysis of organic biomass. Its unique properties make it a versatile asset in agricultural and environmental management. This review paper provides scientific insights into how biochar affects soil’s physical, chemical, and biological properties. It then discusses how these changes can impact crop growth and yield, addressing a key concern for farmers while also considering the potential for biochar to mitigate greenhouse gas (GHG) emissions such as carbon dioxide (CO₂), Nitrous oxide (N₂O), and methane (CH₄), which is of public interest. Additionally, it examines the costs and benefits associated with biochar use, aiming to guide its adoption and suggest future research directions in agricultural applications. Biochar incorporation improves soil properties by enhancing structure, water retention, aeration, nutrient availability, and microbial activity. Different processes impact the effects of biochar on soil, plants, and agricultural systems, influenced by factors like biochar type, soil type, and application rate. Understanding the interaction of these elements, especially over the long term, is vital for promoting the widespread use of biochar in agriculture. Moreover, assessing the economic benefits and costs of biochar in each region is key to convincing farmers to adopt this practice.

Graphical abstract

The view of insects and their microbiota as a holobiont is increasingly relevant as globalization and climate change aids the spread of pests to new areas. Examples of such pests include bark, ambrosia, and woodborer beetles (BAWBBs hereafter) that are important natural components of forest ecosystem processes, but may also cause substantial damage in native and invasive ranges. Microbiota has been shown to perform various functions for these beetles, but we are only beginning to reveal the complex chemically mediated interactions among the beetle, the host tree and their microbiota. In this review we a) summarize current knowledge about the influence of beetle ecology in the formation of the holobiont, b) how microbial compounds may function as beetle semiochemicals, and/or contribute to nutrient acquisition, defence, and maintenance of the holobiont, c) the influence of external factors that affect the holobiont, and d) pinpoint open questions and suggest potential methods needing attention in order to utilize this knowledge in of management of invasive or outbreaking BAWBBs.

Antibiotics like tetracyclines, quinolones, sulfonamides, and β-lactams are commonly used in human and animal health. They have been widely detected in aquatic environments, with concentrations reaching several mg/L. Due to their persistence and resistance to natural degradation, this can lead to severe environmental issues (e.g., resistance genes, resistant bacteria). Consequently, there is an urgent need to remove them from water. Biochar, a porous carbon-based material derived from waste biomass, has been proven effective in removing a wide range of water pollutants (e.g., heavy metals, dyes, persistent organic compounds) due to its favorable physical and chemical properties. Therefore, it has emerged as a promising adsorbent for antibiotics. However, the variability in biochar feedstock (e.g., wood-based biomass, animal manure, aquatic biomass, and municipal solid waste) and the lack of mature modification strategies (e.g., acid/base treatment, oxidation, metal or non-metal doping, and physical methods) pose challenges to its large-scale application. To date, the adsorption efficiency of biochar for antibiotics remains unstable, with removal rates ranging from 40 to 90%. Thus, a timely review of current research progress is crucial. This review summarized the recent advances in biochar modification and its adsorption studies for commonly used antibiotics. The influencing factors, adsorption characteristics and specific adsorption mechanism were comprehensively discussed, and the directions for future research were also proposed.

Graphic abstract

Over the past 45 years, anaerobic membrane bioreactor (AnMBR) technology has transitioned from laboratory-scale research to widespread successful implementation in various wastewater treatment applications, as part of sustainable technology initiatives. Compared to aerobic membrane bioreactor (AeMBR) and conventional anaerobic treatment methods, AnMBR offers numerous well-documented advantages, including efficient reduction of chemical oxygen demand (COD), conversion of organic waste into useful biogas, and production of treated effluent with less sludge generation. Nevertheless, employing AnMBR for treating low to moderate strength wastewater, such as domestic and municipal wastewater, continues to pose challenges due to concerns regarding membrane fouling and low bioenergy recovery efficiency. This article features last 11 year’s publication statistics to visualize global research trends covering the historical development of AnMBRs and related areas, emphasizing key innovations and technological milestones that have driven their evolution in reactor configurations. It includes a performance comparison of AnMBRs across different wastewater treatments, presenting a tabulated analysis and critically discussed various performance parameters such as, COD removal efficiency, biogas production, biomass retention, and sludge generation. The discussion also covered the impact of operational and design parameters on AnMBR performance to enhance the depth of analysis. Despite its effectiveness, AnMBR frequently suffers from substantial membrane fouling and low degradation rate. While addressing such issues, this article also explores both conventional and modified approaches, including the use of bioelectrochemical techniques for fouling control and enhanced methane recovery. Finally, this paper highlights a comprehensive overview and identifies potential areas for future research pertaining to the prevailing issues.

Graphical abstract

The increased demand for energy worldwide and the focus on the green shift have raised interest in renewable energy sources such as biogas. During biogas production, sulphide (H₂S, HS⁻ and S²⁻) is generated as a byproduct. Due to its corrosive, toxic, odorous, and inhibitory nature, sulphide is problematic in various industrial processes. Therefore, several techniques have been developed to remove sulphide from liquid and gaseous streams, including chemical absorption, chemical dosing, bioscrubbers, and biological oxidation. This review aims to elucidate electrochemical and bioelectrochemical sulphide removal methods, which are gaining increasing interest as possible supplements to existing technologies. In these systems, the sulphide oxidation rate is affected by the reactor design and operational parameters, including electrode materials, anodic potential, pH, temperature and conductivity. Anodic and bioanodic materials are highlighted here, focusing on recent material developments and surface modification techniques. Moreover, the review focuses on sulphide generation and inhibition in biogas production processes and introduces the prospect of removing sulphide and producing methane in one single bioelectrochemical reactor. This could introduce BESs for combined biogas upgrading and cleaning, thereby increasing the methane content and removing pollutants such as sulphide and ammonia in one unit.

The increasing demand for protein supplementation in both animal and human nutrition, coupled with the limitations of conventional protein sources, necessitates research into sustainable alternatives. Single-cell proteins (SCPs) are the dried biomass of microorganisms such as algae, yeast, and bacteria that are cultured under controlled conditions. Production of SCP has emerged as a promising solution, offering advantages such as rapid production, minimal land requirement, and adaptability to diverse climatic conditions; however, their large-scale production requires meticulous optimization of entire process of production. Efficient optimization enhances productivity, product quality, and cost-efficiency, making SCP production economically viable, safer and sustainable. Optimization involves standardization of various regulating factors such as temperature, pH, nutrient availability and type, oxygen level, agitation, etc., which requires a large number of experimental trials and a high consumption of resources. To overcome these challenges, optimization of SCP production is increasingly using multivariate statistical techniques, including response surface methodology (RSM), and factorial design. Computer modelling and simulation techniques offer insights into the complex dynamics of production systems. This review discusses popularly followed strategies for optimization of SCP production, beginning with an overview of the fundamentals and significance of SCP. Methods of optimization, including classical methods and RSM, along with integration of mathematical modelling into the Design of Experiment (DoE), are then examined. Case studies have also been discussed to illustrate successful optimization approaches while addressing applications of SCP and, challenges and future directions in SCP optimization/ production.

Graphical abstract

Green tides, characterised by massive blooms of the seaweed Ulva, pose a significant threat to coastal economies and marine ecosystems. This review explores the potential repurposing of harmful Ulva blooms for carbon sequestration, addressing the critical global issue of CO₂ emission. We conducted a comprehensive literature review and examined the conversion of shoreline Ulva biomass into biochar through pyrolysis, a process that can be implemented directly at biorefineries. This approach not only facilitates carbon sequestration but also mitigates greenhouse gas emissions and enhances soil quality through soil amendments. Our review covers data from 2008 to 2022, focusing on the carbon sequestration potential of Ulva during green tide episodes in China and Korea. Our assessment indicates that Ulva biomass has the potential to sequester approximately 3.85 million tons of CO₂ equivalent (CO₂e), with about 1.93 million tons of CO₂e potentially stabilised through biochar conversion. Furthermore, we conducted a hypothetical techno-economic analysis assessing the sustainability and economic viability of Ulva cultivation and biochar production for CO₂ sequestration. These findings suggest that the combined biomass and biochar production could be financially viable and profitable. Despite the challenges posed by green tides, our review highlights their potential role in mitigating global climate change.

Hydroponic cultivation is an efficient, resource-saving technology that produces high yields of high-quality products per unit area without soil. While this technology can save water and fertilisers, water recirculation increases the accumulation of root exudates known to be toxic to the plant, causing growth inhibition. The usage of bioelectrochemical systems (BESs) is well-documented for wastewater treatment, desalination, contamination remediation, bioelectricity generation, etc. In this review we explore the issues associated with the usage of traditional approaches in detecting and removing the phytotoxic substances exudated from plant roots. Furthermore, we investigate the prospects of deploying BESs in hydroponic systems and highlight potential benefits and challenges. The application, feasibility and scalability of BES-hydroponic systems, as well as the possibility of integration with other technologies are all critically discussed. It is concluded that the use of BESs for hydroponic wastewater treatment and for real-time plant growth monitoring represents a novel and valuable strategy. This approach has the potential to overcome limitations of the existing treatment methods and contribute to the advancement of sustainable agriculture.

Graphical abstract

Endocrine-disrupting compounds (EDCs) are ubiquitous in soil, posing serious risks to soil biota, especially earthworms, which have been found to be affected by these compounds, despite not being their typical target organisms. Earthworms are essential for sustaining soil health and quality, by promoting soil aeration, organic matter decomposition and nutrient cycling, among other functions. This review synthesizes available literature evidencing the negative impact of EDC exposure, through traditional endocrine pathways and other toxicological mechanisms, on histopathological, biochemical, molecular and reproductive endpoints of earthworms. The compounds described, in the consulted literature, to induce histopathological, biochemical, genotoxicity and molecular and reproductive alterations include antibiotics, antimicrobial additives, flame retardants, fragrances, fungicides, herbicides, hormones, inorganic ions, insecticides, organic UV filters, parabens, perfluoroalkyl substances, pesticides, petroleum derivatives, plasticizers and polychlorinated biphenyls. These compounds reach soil through direct application or via contaminated organic amendments and water derived from potentially polluted sources. The findings gather in the present review highlight the vulnerability of earthworms to a broad spectrum of chemicals with endocrine disrupting capacity. Additionally, these studies emphasize the physiological disruptions caused by EDC exposure, underscoring the critical need to protect biodiversity, including earthworms, to ensure soil quality and ecosystem sustainability. Ongoing research has provided insights into molecular mechanisms responsive to EDCs in earthworms, including the identification of putative hormone receptors that exhibit functional similarity to those present in vertebrates. In conclusion, this review emphasizes the impact of EDCs in earthworms, especially through non-hormonal mediated pathways, and addresses the need for strong regulatory frameworks to mitigate the detrimental effects of EDCs on soil invertebrates in order to safeguard soil ecosystems.

Graphical abstract