Reviews in Environmental Science and Bio/Technology最新文献

Based on the most recently published data, we definitively estimated that the annual global production of sewage sludge may rise from ~ 53 million tons dry solids currently to ~ 160 million tons if global wastewater were to be treated to a similar level as in the 27 European Union countries/UK. It is widely accepted that the agricultural application is a beneficial way to recycle the abundant organic matter and plant nutrients in sewage sludge. However, land application may need to be limited due to the presence of metals. This work presents a meticulous and systematic review of the sources, concentrations, partitioning, and speciation of metals in sewage sludge in order to determine the impacts of sludge application on metal behavior in soils. It identifies that industrial wastewater, domestic wastewater and urban runoff are main sources of metals in sludge. It shows conventional treatment processes generally result in the partitioning of over 70% of metals from wastewater into primary and secondary sludge. Typically, the order of metal concentrations in sewage sludge is Zn > Cu > Cr ≈ Pb ≈ Ni > Cd. The proportion of these metals that are easily mobilised is highest for Zn and Ni, followed by Cd and Cu, then Pb and Cr. Sludge application to land will lead to elevated metal concentrations, and potentially to short-term changes to the dominant metal species in soils. However, the speciation of sludge-associated metals will change over time due to interactions with plant roots and soil minerals and as organic matter is mineralised by rhizo-microbiome.

The interaction of bio–geosphere dates to the formation of first unicellular microbes on earth. However, it is only relatively recently that the complex biological interactions are observed, characterised, and simulated for its use in the domain of geotechnical engineering. Also, many bioinspired approaches have been utilised in computational geotechnics for optimisation and data analysis process. The living phase present in the soil system hold a bearing on the majority of geochemical reactions and assist in modifying its fundamental and engineering behaviour. It necessitates revaluation and rescrutinisation of the conventional theories and formulations in geotechnical engineering, where soil has always been considered as an inert engineering material from biological perspective. To that end, this manuscript provides a critical review on biological approaches used in geotechnical engineering by highlighting the ongoing developments, achievements, and challenges to implement the processes. The review further emphasises the role of biological systems on the alteration of fundamental properties of soils and their consequences on effective stress, strength and stiffness, volume change and conduction properties of soils. Overall, the manuscript provides a basic understanding on the biological intervention in the soil system and the importance of consideration of the fourth phase in the soil system, i.e., the living phase, while describing such interventions.

Soil erosion is a complex natural process that occurs by either individual or combined actions of wind, hydraulic currents, waves, and rain. This study comprehensively reviews biocementation-based soil stabilisation techniques for developing erosion-resilient landforms through an ecologically conscious strategy. The different pathways for biocementation occurring in nature are discussed with a focused view on the microbially induced carbonate precipitation (MICP) technique. MICP relies on biogenic calcium carbonate (CaCO₃) precipitation via the urea hydrolysis route to bind the soil grains. The kinetics and factors affecting MICP are succinctly discussed to highlight the practical challenges associated with biocementation. This study emphasises the influence of MICP on erosion resistance (aeolian and hydraulic) and geotechnical properties of soils. The critical assessment of the previous studies revealed that aeolian and hydraulic erosion can be effectively controlled with a small to moderate quantity of biogenic CaCO₃ (2% to 10% of soil weight). MICP marginally influences the hydraulic conductivity of soils with a substantial improvement in compressive strength, making it desirous over traditional soil cementation agents for erosion control due to the limited intervention to natural groundwater flow. However, the scientific design and findings of the previous laboratory-scale and pilot-scale research are still inconsistent for standardising biocementation techniques to transition towards upscaling. This study presents critical insights to the researchers of the environmental, geotechnical and geoenvironmental engineering domains to design their upcoming studies to tackle the challenges required for upscaling biocementation technology.

The aquaculture industry is rapidly developing, generating a high amount of wastewater. Inland aquaculture effluents contain nutrients and other substances that can cause eutrophication and the emergence of resistive organisms if released into the environment. Hence, aquaculture wastewater should be treated appropriately for reuse in different applications or safely released into the environment, promoting a sustainable industry and a circular economy. The current review provides insight into aquaculture wastewater generation, constituents, and treatment through various technologies. This study’s treatment technologies could be classified as physical, chemical, and biological. SWOT analysis was conducted on each technology to provide an in-depth understanding of the advantages and drawbacks. Suggestions were also stated to shed light on the importance of a sustainable aquaculture industry and the means to transition toward a circular economy.

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Energy and environmental issues related to conventional fossil-derived products and fuels have led researchers to focus on alternative, more environmentally-friendly processes, such as the production of microbial oils from renewable feedstocks or even pollutants as sustainable sources of biofuels, allowing to progressively move away from the use of fossil fuels. Among the oleaginous yeasts, Yarrowia lipolytica is a highly promising cell factory and microbial oil producer because of its high capacity to accumulate lipids for subsequent biofuel production. Y. lipolytica also stands out for its ability to assimilate various carbon sources, even at low cost, reaching lipid concentrations of at least 30% by weight with non-genetically modified strains, and even much higher values with engineered organisms. Among others, fatty acids have attracted recent interest as substrates for their lower cost and possible production from pollutants compared to sugars. This review pays special attention to some of those emerging carbon sources, i.e., carboxylic acids and even greenhouse gases. Besides, another focus is to provide detailed up to date information on the main characteristics and factors that most influence the fermentation process of this yeast, with the ultimate aim of optimising the bioconversion process and the synthesis of useful metabolites. Besides, the reader will find comprehensive information on the industrial applicability of the synthesised lipids, in addition to the production of biofuels. Apart from lipids, other metabolites of interest that can be synthesised by Y. lipolytica are also discussed.

Spent coffee ground (SCG) is a primary by-product obtained during soluble coffee processing and could be used for high-value products due to its protein content. The SCG is a rich source of cellulose, hemicellulose, lignin, lipids and proteins. The bioactive peptide obtained after protein hydrolysis has great potential as an antioxidant, antimicrobial, and anti-mutagenic agent and a better understanding is a prerequisite for proper utilization of the natural and renewable source of protein to attain a sustainable approach. Moreover, by utilizing SCG-derived peptides we can reduce the contamination of these residues at an agronomical scale. In this review, we discussed the spent coffee ground protein-based peptides and also high-lightened the properties of these valuable bioactive peptides in addition to other industrially important metabolites. Conclusively, the SCG peptides can be an interesting substitute to plant protein with functional properties in food industries, and at the same time utilization of SCG would reduce the bio-waste burden.

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To reduce the crop losses associated with biotic and abiotic stresses, novel sensor technologies that can monitor plant health and predict and track plant diseases in real time are required. Plant sensors based on wearable technologies are placed directly on the plant leaf or stem. The health status of the plant is reflected by various biomarkers and microenvironmental parameters, which are converted into electric readouts by the sensors for convenient analysis. Herein, the latest research progress in the field of wearable plant sensors is evaluated, and the sensors are classified according to their individual functions. Moreover, the design principles and working mechanisms of previously reported wearable sensors are analyzed, and the design features adopted to overcome the difficulties associated with precision agriculture are explored. Finally, the challenges and future development prospects in this field are outlined. This review contributes to the growing body of literature on wearable plant sensors, underscoring their critical role in mitigating crop losses through real-time plant health monitoring and disease prediction. Advancements in wearable plant sensors could ultimately revolutionize crop production and sustainability by enabling more precise, efficient, and proactive farming practices.

The technology known as carbon capture and storage (CCS) can significantly reduce greenhouse gas emissions on a massive scale. The whole process and large-scale CCS projects are still in the exploratory stage from project demonstration stage to commercialization stage because to the significant expenditure, prolonged operating term, and numerous technological connections involved. The investment cost of CCS, the advancement of CCS technology, and the safety of CCS operation are its primary points of emphasis. There are several ways to successfully absorb carbon dioxide (CO₂), but they all have the drawback of having large investment costs. For the smooth development of capturing technology, the issues of cost and efficiency must be resolved. Transporting CO₂ is usually necessary since its source and storage location are dispersed and far apart. This is seen to be the most challenging issue. The secret to ensuring the success of CCS projects is understanding how to perform efficient economic evaluation when making investment decisions in light of the high cost of CCS. The influence of measures like increased carbon taxes and government subsidies will hasten the commercialization of CCS projects. We advise a thorough assessment of CCS projects to support their strategic positioning with nations and investors and deepen decision-makers' understanding of the technical feasibility and economics of CCS projects to obtain a more thorough support. This recommendation is based on the progress and challenges in the development of each module.