An overview of operations and processes for circular management of dredged sediments

Crocetti, Paolo; González-Camejo, J.; Li, K.; Foglia, Alessia; Eusebi, Anna Laura; Fatone, Francesco

doi:10.1016/j.wasman.2022.04.040

Cited by 55 publications

(18 citation statements)

References 95 publications

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“…The methods commonly used to treat dredged water include physical methods based on sedimentation and physicochemical methods based on coagulation (Crocetti et al, 2022). Coagulation can effectively remove most suspended colloidal particles and partially dissolved pollutants from water (Tafvizi & Husain, 2021; Zhang, Liu, et al, 2023), with many chemical coagulants widely used in water and wastewater treatment, such as inorganic low molecular compounds, organic high molecular compounds, and biopolymers (Liu, Liu, et al, 2023).…”

Section: Introductionmentioning

confidence: 99%

“…Chemical oxygen demand (COD), total phosphorus (TP), and ammonia nitrogen (NH 4 + -N) concentrations in dredged water exhibit a highly significant positive correlation with suspended solids (SS) (Nie et al, 2015). Generally, dredging water treatments focus on the removal of SS, which is closely related to the properties of dissolved organic matter (DOM), with the presence of DOM in dredged water hindering SS removal (Crocetti et al, 2022). The existence of a large number of DOMs is mainly due to organic matter release in sediment contaminated by agricultural non-point sources and industrial sewage pollution (Rutlidge et al, 2021).…”

Section: Introductionmentioning

confidence: 99%

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Purification of dredged water by magnetic coagulation: Response surface optimization and dissolved organic matter removal characteristics

Xiao,

Feng,

Zhang

et al. 2024

Water Environment Research

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In the present study, magnetic coagulation was used to treat dredged water and the response surface method was used to optimize process parameters. The dissolved organic matter (DOM) removal characteristics were characterized by three‐dimensional fluorescence spectrometry and ultra‐high resolution mass spectrometry. During the magnetic coagulation process, the suspended solids (SS) removal rate increased initially and then decreased under conditions of increasing magnetic powder dosage and stirring rate. After magnetic coagulation and precipitation for 20 min, the contents of SS, ammonia nitrogen, chemical oxygen demand, and total phosphorus in the treated dredged water met the requirements of the discharge standard (GB8978–1996, China). Three‐dimensional fluorescence results showed that magnetic coagulation selectively removed fulvic acids and humic acid substances. After magnetic coagulation with precipitation for 10 min and 20 min, the total relative content of lignins, tannins, proteins, lipids, aminosugars, unsaturated hydrocarbons, condensed aromatic structures, and carbohydrates decreased by 26.3% and 39.4%, respectively. After magnetic coagulation, the distribution range of small molecule DOM shifted to the low H/C and high O/C regions. This study provides a novel perspective for studies on the removal of DOM in dredged water by magnetic coagulation.Practitioner Points SS and DOM removal were significantly enhanced by the use of magnetic coagulation. SS removal efficiency was affected by stirring rate and magnetic powder dosage. Magnetic coagulation selectively removed fulvic acids and humic acid substances. DOM molecule shifted to low H/C and high O/C regions after magnetic coagulation.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Purification of dredged water by magnetic coagulation: Response surface optimization and dissolved organic matter removal characteristics

Xiao,

Feng,

Zhang

et al. 2024

Water Environment Research

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“…Conventional disposal methods, such as land disposal, not only consume valuable land resources but also contribute to environmental pollution. Similarly, marine disposal alternatives, involving offshore abandonment, incur considerable costs, while near-shore abandonment poses risks of marine environment pollution and depletion of marine resources [5]. On the other hand, construction projects like highways and railways demand substantial quantities of highquality fill materials.…”

Section: Introductionmentioning

confidence: 99%

Physical and Mechanical Properties of All-Solid-Waste-Based Binder-Modified Abandoned Marine Soft Soil

Liu,

Yang,

et al. 2024

JMSE

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Large quantities of abandoned marine soft soil are generated from coastal engineering which cannot be directly utilized for construction without modification. The utilization of traditional binders to modify abandoned marine soft soil yields materials with favorable mechanical properties and cost efficiency. However, the production of traditional binders like cement leads to environmental pollution. This study uses a CGF all-solid-waste binder (abbreviated as CGF) composed of industrial solid waste materials such as calcium carbide residue (CCR), ground granulated blast furnace slag (GGBS), and fly ash (FA), developed by our research team, for the modification of abandoned marine soft soil (referred to as modified soil). It is noteworthy that the marine soft soil utilized in this study was obtained from the coastal area of Jiaozhou Bay, Qingdao, China. Physical property tests, compaction tests, and unconfined compressive strength (UCS) tests were conducted on the modified soil. The investigation analyzed the effects of binder content, compaction delay time, and curing time on the physical, compaction, and mechanical properties of CGF-modified soil and cement-modified soil. Additionally, microscopic experimental results were integrated to elucidate the mechanical improvement mechanisms of CGF on abandoned marine soft soil. The results show that after modification with binders, the water content of abandoned marine soft soil significantly decreases due to both physical mixing and chemical reactions. With an increase in compaction delay time, the impact of chemical reactions on reducing water content gradually surpasses that of physical mixing, and the plasticity of the modified soil notably modifies. The addition of binders results in an increase in the optimum moisture content and a decrease in the maximum dry density of CGF-modified soil, while the optimum moisture content decreases and the maximum dry density increases for cement-modified soil. Moreover, with an increase in binder content, the compaction curve of CGF-modified soil gradually shifts downward and to the right, while for cement-modified soil, it shifts upward and to the left. Additionally, the maximum dry density of both CGF-modified and cement-modified soils shows a declining trend with the increase in compaction delay time, while the optimum moisture content of CGF-modified soil increases and that of cement-modified soil exhibits a slight decrease. The strength of compacted modified soil is determined by the initial moisture ratio, binder content, compaction delay time, and curing time. The process of CGF modification of marine soft soil in Jiaozhou Bay can be delineated into stages of modified soil formation, formation of compacted modified soil, and curing of compacted modified soil. The modification mechanisms primarily involve the alkali excitation reaction of CGF itself, pozzolanic reaction, ion-exchange reaction, and carbonization reaction. Through quantitative calculations, the carbon footprint and unit strength cost of CGF are both significantly lower than those of cement.

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“…Given the increasing legal requirements regarding sediment management, conventional methods or the "no-action" option are no longer viable for economic, environmental and social plans [31][32][33]. Dredged sediment management is therefore a challenge and an opportunity for port authorities [28,34,35] to apply circular economy principles by considering sediment as a sustainable resource rather than hazardous waste [36][37][38].…”

Section: Introductionmentioning

confidence: 99%

“…Research has proven the potential of recycling dredged sediment in many applications related to the construction industry [36,56,94]. However, market demand appears to be lagging behind encouraging study results; the real beneficial reuse of dredged sediment is still very limited [95,96].…”

Section: Introductionmentioning

confidence: 99%

Characterizing Harbor Dredged Sediment for Sustainable Reuse as Construction Material

et al. 2023

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An unprecedented rate of construction has profoundly increased the risk of scarcity of natural resources and threatened ecosystem sustainability. To establish an effective sustainable development policy, it is imperative to promote the use of responsible production channels, including waste recycling. Reuse of harbor dredged sediment is commonly investigated as a valuable alternative to non-renewable natural resources needed for construction. Sediment characterization is decisive in the valorization process, aiming to identify potential recycling paths. Existing research efforts, however, have rarely investigated case studies in developing countries. Moreover, they have tended to focus on the technical aspects, ignoring economic feasibility, which carries important implications. This paper fills this gap first by meticulously selecting laboratory tests for characterization within the means available in developing countries and second by conducting a cost-benefit analysis. The port of Safi, Morocco, was chosen for the implementation of the adopted approach. Results showed that dredged sediment is a sand readily reusable as a construction aggregate. Several applications are possible, the most interesting one being concrete works, as a substitute for conventional sand. While treatment by washing and dehydrating proved necessary, cost-benefit analysis confirmed the profitability of recycling. Hence, beneficial reuse of dredged sediment as construction material is technically and economically feasible.

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An overview of operations and processes for circular management of dredged sediments

Cited by 55 publications

References 95 publications

Purification of dredged water by magnetic coagulation: Response surface optimization and dissolved organic matter removal characteristics

Purification of dredged water by magnetic coagulation: Response surface optimization and dissolved organic matter removal characteristics

Physical and Mechanical Properties of All-Solid-Waste-Based Binder-Modified Abandoned Marine Soft Soil

Characterizing Harbor Dredged Sediment for Sustainable Reuse as Construction Material

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