Routine waterway dredging activities generate huge volumes of dredged sediment. The remediation of dredged contaminated sediment is a worldwide challenge. Novel and sustainable ex-situ remediation technologies for contaminated sediment have been developed and adopted in recent years. In this review paper, the state-of-art ex-situ treatment technologies and resource utilisation methods for contaminated sediment were critically reviewed. By applying different techniques, sediment could been successfully transformed into sustainable construction materials, such as ceramsite, supplementary cementitious materials, fill materials, paving blocks, partition blocks, ready-mixed concrete, and foamed concrete. We highlighted that proper remediation technologies should be cleverly selected and designed according to the physical and chemical characteristics of sediment, without neglecting important aspects, such as cost, safety, environmental impacts, readiness level of the technology and social acceptability. The combination of different assessment methods (e.g., environmental impact assessment, cost-benefit analysis, multi-criteria decision analysis and life cycle assessment) should be employed to comprehensively evaluate the feasibility of different sustainable remediation technologies. We call on the scientific community in a multidisciplinary fashion to evaluate the sustainability of various remediation technologies for contaminated sediment.

Cadmium (Cd) uptake and accumulation in crop plants, especially in wheat (Triticum aestivum) and rice (Oryza sativa) is one of the main concerns for food security worldwide. A field experiment was done to investigate the effects of limestone, lignite, and biochar on growth, physiology and Cd uptake in wheat and rice under rotation irrigated with raw effluents. Initially, each treatment was applied alone at 0.1% and combined at 0.05% each and wheat was grown in the field and then, after wheat harvesting, rice was grown in the same field without additional application of amendments. Results showed that the amendments applied increased the grain and straw yields as well as gas exchange attributes compared to the control. In both crops, highest Cd concentrations in straw and grains and total uptake were observed in control treatments while lowest Cd concentrations was observed in limestone + biochar treatment. No Cd concentrations were detected in wheat grains with the application of amendments except limestone (0.1%). The lowest Cd harvest index was observed in limestone + biochar and lignite + biochar treatments for wheat and rice respectively. Application of amendments decreased the AB-DTPA extractable Cd in the soil while increasing the Cd immobilization index after each crop harvest. The benefit-cost ratio and Cd contents in plants revealed that limestone + biochar treatment might be an effective amendment for increasing plant growth with lower Cd concentrations.

Ammonia (NH₃) emissions, the majority of which arise from livestock production, are linked to high concentration of PM₂.₅ and lower air quality in China. NH₃ mitigation options were well studied at the small-scale (laboratory or pilot), however, they lack of a large-scale test in China. This study fills this crucial gap by evaluating the cost-benefit of pioneering NH₃ mitigation projects carried out for a whole county – Sheyang, Jiangsu province, China. Measures were implemented in 2019 following two distinct strategies, improved manure treatment for industrial livestock farms, and collection and central treatment for traditional livestock farms. Emission reductions of 16% were achieved in a short time. While this is remarkable, it falls short of expectations from small-scale studies. If measures were fully implemented according to purpose and meet expectations from the small scale, higher emission reductions of 42% would be possible. The cost benefit analysis presented in this study demonstrated advantages of central manure treatment over in-farm facilities. With improved implementation of mitigation strategies in industrial livestock farms, traditional livestock farms may play an increasing role in total NH₃ emissions, which means such farms either need to be included in future NH₃ mitigation policies or gradually replaced by industrial livestock farms.The study found an agricultural NH₃ reduction technology route suitable for China's national conditions (such as the “Sheyang Model”).

Beach nourishment practices are a key aspect in coastal management plans for stakeholders and communities. Stemming from a concrete case-study (Tuscany), this research analyzes: (i) principal problems of current law regulating dredging, (ii) gaps in technical guidelines, (iii) advantages of integrated approaches to the decision-making process, (iv) possible applicable nourishment options and their costs and benefits. Our results show that sand compatibility is driven mainly by grain-size stability due to the occurrence of lower pollution levels in off-shore deposits than in threatened beaches, thus current laws and guidelines should be improved to fill the evident gap in the evaluation process and to include a more complete approach to data evaluation and an integrated approach to ecotoxicity evaluation, which is relevant in cases of geochemical anomalies. The cost-benefit analysis performed indicates that only dredging intended to manage more than 1millionm3 of aggregates would represent a real advantage for local communities.

The continued rise in atmospheric carbon dioxide (CO2) levels is driving climate change and temperature shifts at a global scale. CO2 Capture and Storage (CCS) technologies have been suggested as a feasible option for reducing CO2 emissions and mitigating their effects. However, before CCS can be employed at an industrial scale, any environmental risks associated with this activity should be identified and quantified. Significant leakage of CO2 from CCS reservoirs and pipelines is considered to be unlikely, however direct and/or indirect effects of CO2 leakage on marine life and ecosystem functioning must be assessed, with particular consideration given to spatial (e.g. distance from the source) and temporal (e.g. duration) scales at which leakage impacts could occur. In the current mesocosm experiment we tested the potential effects of CO2 leakage on macrobenthic assemblages by exposing infaunal sediment communities to different levels of CO2 concentration (400, 1000, 2000, 10,000 and 20,000 ppm CO2), simulating a gradient of distance from a hypothetic leakage, over short-term (a few weeks) and medium-term (several months). A significant impact on community structure, abundance and species richness of macrofauna was observed in the short-term exposure. Individual taxa showed idiosyncratic responses to acidification. We conclude that the main impact of CO2 leakage on macrofaunal assemblages occurs almost exclusively at the higher CO2 concentration and over short time periods, tending to fade and disappear at increasing distance and exposure time. Although under the cautious perspective required by the possible context-dependency of the present findings, this study contributes to the cost-benefit analysis (environmental risk versus the achievement of the intended objectives) of CCS strategies.

Assessment of environmental consequences of agri-food products during their life cycle is currently identified as the most important and efficient way to investigate agricultural systems. In addition to the environmental impacts, energy and economic issues are considered major issues in the life cycle of products. The present study aimed to investigate and assess the energy flow, environmental, and economic dimensions during shallot production in farms of Iran. Given the limited number of shallot farmers, the required data were collected from 22 shallot farms through the census method in the Shahrekord region. Based on the results obtained from the energy analysis, energy input and output and energy ratio (ER) were obtained as 107,145 and 36,243 MJ ha⁻¹ and 0.4, respectively. Also, electricity was identified as major contributor to energy consumption with the contribution of 74%. Results related to the economic analysis of shallot production revealed that the values of total production, economic productivity, and benefit-cost ratio (BCR) are 15,672 US$ ha⁻¹, 10.89 kg US$⁻¹, and 8.45, respectively. Based on the life cycle assessment results, the contribution of input consumption in the farms and input production to total environmental impacts were determined as 55 and 45%, respectively. Also, normalization of results showed that the marine ecotoxicity (ME) and global warming potential (GWP) impact categories were the main environmental impacts during shallot production. ME and GWP impacts can be attributed to the indirect emissions of electricity and direct emissions of inputs in the farm, respectively.

Countries face a serious problem due to the generation and management of higher volumes of waste. Large-scale production of waste has promoted the establishment of various operations (collection, transport, treatment and disposal) for its management. When a MSW management system is implemented, it can generate different impacts or consequences (internal or external impacts). Generally, external impacts (social and environmental impacts) are not reflected in MSW economic analysis or taken into consideration in decision-making processes in regard to MSW management options. For this reason, the objective of this paper is present a methodology with which is viable to conduct the technical-economic analysis of municipal solid waste management projects based on social cost-benefit analysis (sCBA) as it considers internal and external impacts. Its main objectives are to determine the total benefits (the difference between revenues and costs) generated by a project and to reduce uncertainty and risk of investing in particular MSW management system. Finally, a case study was carried out to verify the validity of the methodology through analysis and valuation of different impacts of a light packaging waste and bulky waste facility. Through the application of the methodology, it has been possible to visualize that this facility is viable operationally (BP = 42.94 €/ton) as economically (BT = 87.73 €/ton).