Sediment Disposal Research Articles

3D simulations of dredged sediment disposal plumes over a realistic bathymetry using a two-phase model

3D simulations of dredged sediment disposal plumes over a realistic bathymetry using a two-phase model

Reuse of harbour and river dredged sediments in adobe bricks

Dredged sediments from ports and rivers are treated as waste material. The disposal of waste sediments has environmental concerns and requires financial resources. Dredged sediments reuse in building material such as adobe bricks can provide an alternate solution to valorize and handle this waste material. Adobe bricks are eco-friendly construction materials manufactured with clayey soil and fibers. Natural fibers addition improves mechanical and thermal characteristics of adobe bricks.In this research, a pilot study was conducted to manufacture adobe bricks from harbor dredged sediments and replicate the procedure to manufacture adobe bricks for river dredged sediments. Harbor sediments were taken from Dunkirk port, France. The physical and chemical characteristics of these sediments were analyzed. Sediments suitability for adobe bricks with grains size and Atterberg limit was discussed with different approaches. Bricks were manufactured by mixing Dunkirk sediments and saturated hemp shiv at different hemp shiv content. Sediments and fibers were mixed with a mortar mixer and molded into specimens of 4*4*16 cm3. Dynamic compaction was opted to compact the bricks. Drying of bricks was done in the oven at 40 °C. Finally, sediments mixing, molding and compaction procedures were derived and problems encountered during were discussed.The procedure derived from Dunkirk sediments was implemented on Usumacinta River sediments to make adobe bricks with the addition of palm oil flower fibers (POFl). Characteristics of Usumacinta River sediments and palm oil flower fibers were found to use in adobe bricks. Palm oil flowers fibers were cut with a knife mill of grid-2 cm and grid-3 cm. Dunkirk sediments bricks manufacturing process was repeated to make bricks from Usumacinta sediments.Laboratory scale manufacturing and testing of bricks from Dunkirk port sediments and Usumacinta River sediments allows to observe the valorization of dredged sediments in adobe bricks with mechanical perspectives. In this study, properties of bricks manufactured by both harbor and river dredged sediments such as tensile strength, toughness and fibers distribution inside the bricks were studied and compared.

Phytomanagement of a Trace Element-Contaminated Site to Produce a Natural Dye: First Screening of an Emerging Biomass Valorization Chain

The study of different possible biomass valorization routes is crucial in order to diversify phytomanagement options, allowing the landowner/stakeholder to choose the best option based on site characteristics and the benefits of local value chains. In the current study, field and laboratory experiments were conducted to assess the suitabilitity of Malva sylvestris L. for the phytoattenuation of a dredged sediment disposal site contaminated with trace elements (trace element (Cd, Cu, Pb, and Zn). The selected crop was Malva sylvestris, a flowering plant from which a colourant can be extracted to be used in dying of textiles as a way to valorize the produced biomass grown on this contaminated land. Under the conditions of the investigated site, the analysis of TE in the sediment and the biomass matrix showed no effect of M. sylvestris on the sediment TE contamination mobility with an excluder phenotype (Bioconcentration factor < 1). Metal concentrations were found to be the highest in the leaves followed by in the stem and flower. The dye extract obtained from the flower part of M. sylvestris permitted the silk alum-pretreated fabric to be dyed yellow, and the TE concentration in the dyed textile fabrics respected the threshold values set by OEKO-Tex standard 100.

Optimization of an Eco-Friendly Hydraulic Road Binders Comprising Clayey Dam Sediments and Ground Granulated Blast-Furnace Slag

This study investigated the potential use of Zerdezas dam Calcined Sediments (CS) and El-Hadjar Blast Furnace Slag (GGBS) from northern Algeria as a partial replacement of cement (C) in normal hardening hydraulic road binders. Two binder mix designs were optimized using a Response Surface Methodology (RSM). The first mix, 50C35GGBS15CS, consisted of 50% cement, 35% blast furnace slag, and 15% calcined sediment. The second mix, 80C10GGBS10CS, consisted of 80% cement, 10% blast furnace slag, and 10% calcined sediments. The tests of workability, setting time, volume expansion, compressive and flexural strengths, porosity, and SEM were conducted to ensure that both mixes meet the standard requirements for road construction binders. The two proposed mixes were qualified as normal hardening hydraulic road binder. The reuse of the sediments will contribute to a better disposal of dam sediments and steel industry waste and to preserve natural resources that are used for manufacturing cement. It will also contribute to the environmental impact reduction of cement clinker production by reducing greenhouse gas emissions.

THE INFLUENCE OF A HIGH-VOLTAGE DISCHARGE ON THE OIL BOTTOM SEDIMENTS FORMED AT THE OIL STORAGE FACILITIES OF THE ATASU-ALASHANKOU STATION

From three to ten per cent of the total oil produced can ultimately not be used for further processing. When the oil is transported by oil pipelines and oil tankers and stored in reservoirs, oil bottom sediments are deposited on the bottom comprising particles of mineral (non-oil origin) and the heaviest hydrocarbons, mainly paraffin series, whose specific gravity is higher than the density of oil and water. For reliable operation of the tanks, it must be periodically cleaned from the accumulated sediment. The study novelty is the use of the electrohydraulic effect for the processing of oil bottom sediments and creation of a waste-free technology for the disposal of oil bottom sediments in field conditions. The optimal mode for electrohydraulic impact, ensuring the destruction of bottom deposits of oil in the oil storage tanks of the Atasu-Alashankou station, is determined.

Characterization, Spatial Variation and Management Strategy of Sewer Sediments Collected from Combined Sewer System: A Case Study in Longgang District, Shenzhen.

In the urban drainage system, the formation of sewer sediments is inevitable, and the removal of sewer sediments is necessary for system maintenance. Disposal of arisings from sewer sediment removal is becoming a serious environmental issue. The current knowledge of sewer sediments is limited, which is restrained to sewer sediments management. To better understand this municipal waste, the sewer sediments of a combined sewer system in Longgang District, Shenzhen were collected and characterized, and the spatial distribution characteristics of contaminants were analyzed. Based on the bivariate correlation analysis, it is found that many contaminants in sewer sediments have a strong relationship with spatial variables. Compared to the sewer sediments in industrial areas, those in residential areas contain higher concentrations of Hg and phosphorus. The sediments in the sewage conduit also contain more organic matter (OM), phosphorus, Cu, and Ni, and the sediments in the rainwater conduit contain a higher concentration of Cd. Moreover, the sediments produced in different catchments also show huge differences in the content of contaminants. These spatial distribution characteristics may provide help for the further classification of sewer sediments, thereby making the disposal of sediments more targeted. According to the local standards of sludge disposal, land application and incineration are not suitable for managing sewer sediments due to the low OM content and poor lower heating value (LHV). Although sanitary landfill is feasible for sewer sediments disposal, the complicated composition of sewer sediments still poses the risk of polluting the surrounding environment. The management of sewer sediments via the production of building materials is a promising technical route that can avoid the migration of hazardous contaminants and produce valuable products. This study may improve our understanding of sewer sediments and provide a reliable recommendation for sewer sediment management.

Improvement of wastewater treatment technology with sediment disposal at coke-chemical enterprises

Охарактеризовано стічні води коксохімічних підприємств. На дільниці біохімочищення ПРАТ «ЮЖКОКС», м. Кам’янське, проведено експеримент із очищенням стоків від полютантів глауконітом. Рекомендовано до впровадження запатентовану конструкцію флотатора з перегородками. Ефективність очищення від фенолів запропонованим способом становить 35,7 %, роданідів – 32,1 %, загального амоніаку – 57,2 %, смолистих речовин – 95,0 %. В лабораторних умовах показано можливість пролонгованої дії глауконіту з катіонним флокулянтом (до чотирьох циклів) з ефективністю вилучення фенолів до 50 % та смолистих речовин – до 95,37 %. Запропоновано механізм очищення стоків глауконітом з катіонним флокулянтом. При утилізації осаду з флотатора встановлено можливість використання технології геотекстильних контейнерів. В результаті досліджень зменшено показник зневоднення шламу з 92 % до 50 % вологості осаду. Проведено фізико-механічні дослідження при використанні глауконітового осаду як добавки до асфальтобетонної суміші в лабораторії ПП «Сегмент», м. Кам’янське. В результаті випробувань встановлено, що асфальтобетонна суміш з додаванням добавки глауконітового осаду відповідає вимогам ДСТУ БВ 27-119:2011 «Суміші асфальтобетонні і асфальтобетон дорожній та аеродромний. Технічні умови».

Radiation as social relation

A new nuclear power station is currently being built in the Southwest of the UK at Hinkley Point. The construction of the cooling water system for Hinkley Point C is underway but there is controversy over the tunnelling required to install the huge pipes that will run for over 3 kilometres into the Bristol Channel. EDF, the operating company, want to deposit 600,000 tonnes of sediment on the far side of the Channel, at the licensed site for such disposal, the Cardiff Grounds. The Cardiff Grounds are in Wales and there is a public outcry at the prospect of the arrival of this English mud, and the concern that it might carry toxic sediment from the previous, far less regulated material deposits produced over the past 60 years by the adjoining stations at Hinkley Point A (now decommissioned) and Hinkley Point B (currently operational). Earlier disposal of sediment led to protests and a petition that triggered a debate in the Welsh Parliament. EDF have supplied evidence that levels of radiation in the mud are so low as to be not classed as radioactive under UK law. They offer comparisons with naturally occurring radiation: the levels of radiation in the mud would be 10,000 times less than an airline pilot's annual dose, 750 times less than the average dose received by a resident of Pembrokeshire due to naturally occurring radon, equivalent to eating 20 bananas a year. These comparisons do not convince local people. This paper explores the difficulties inherent in producing public trust in radiation measures. Radiation cannot be seen, smelt or felt. It must be detected through instruments, evaluated through calculations and interpreted by experts. Experts are often exasperated by the distinctions that people draw between natural and human‐made radiation. Still, they also miss the point that most people approach radiation as a social, rather than a physical or chemical, relation. The political and social histories through which nuclear imaginaries are produced and reproduced shape understandings of toxicity in ways that lead people to place more trust in correlation than in causality.

Transport and fate of microplastics from riverine sediment dredge piles: Implications for disposal

Microplastics (MPs) are an environmental problem of growing concern. Aquatic sediments are considered as a final sink for MPs, but dredging can remobilize sedimentary MPs into both aquatic and terrestrial ecosystems. Although dredging is globally used for waterway deepening and ecological restoration, the environmental impacts of dredging on MP pollutants has not been previously assessed. In this study, Nile Red staining combined with micro-FTIR methods showed sediments containing high MP concentrations (6060–37610 n/kg·DW) from urban/suburban segments of a plain river network in Southeast China. The dredged sediments were stored in piles on farmlands, whereby MPs were subsequently dispersed to surrounding soils and surface waters while awaiting a permanent disposal option. MP concentrations in the soils surrounding the pile were higher in the dry season (wind dispersion), while MP concentrations in waters downstream of the piles were higher in the wet season (rainfall/runoff erosion). Whether dredge sediments are finally used to fertilize farmland, as fill material for coastal land reclamation or dumped into the ocean, MPs have the potential for remobilization into the environment causing concerns with aquatic food webs, agricultural production and human health. Therefore, disposal of dredge sediments containing MPs requires careful assessment to minimize potential environmental impacts.

Optimized utilization studies of dredging sediment for making water treatment ceramsite based on an extreme vertex design

The minimal recycling and large accumulation of dredging sediment has resulted in a range of social and environmental problems. To solve the residual sediment disposal problems, a series of experiments utilizing the dredging sediment as ceramsite components were performed. Zeolite and bentonite were introduced as additives. In this work, the extreme vertices design method was used to determine the optimal proportion of a three-component mixture for sintering sediment ceramsite. The results showed that the maximum specific surface area of 51.68 m2/g and the largest porosity of 53.93% could be achieved with the optimal contents of 40.30 wt.% sediment, 39.42 wt.% zeolite, and 20.28 wt.% bentonite. The characterizations (mineralogical characteristics, physical characteristics, microstructure characteristics, and toxic metal leaching characteristics) of the sediment ceramsite were measured. The property tests of the sediment ceramsite showed that the dredging sediment played an important role in the sintering process of the ceramsite. The heating process can be divided into three stages, and the main new crystalline phases of the sediment ceramsite were clinoptilolite (Na(AlSi5O12)·4H2O), albite-calcian ordered (NaCaAl(SiAl)2O8) and quartz (SiO2). The sediment ceramsite presented a rough surface and had an abundant porous structure with elongated and interconnected pores (diameters between 0.05 and 10 μm). Additionally, the sediment ceramsite was verified to meet the standard of lightweight ceramsite (bulk density was 0.89 g/cm3) and was macroporous (the mean pore size was 3.3472 μm), nontoxic (concentrations of toxic metal leaching were all below the industry standard) and suitable for the water treatment system.

Technogenic deposits formed from dredged sediments deposition: toxic effects on earthworms

Dredged sediments are often disposed on land areas and can cause adverse effects on soil biota, since these materials generally may contain toxic agents. This work examines the ecotoxicological effects on earthworms exposed to technogenic deposits formed from the deposition of dredged sediments from an urban tropical lagoon. Such evaluation supports the understanding of the ecological effects derived from dredged sediments in the tropics, as well as the influence of soil properties in the toxicity. To simulate dredged sediment disposal under tropical conditions, a dredged sediment sample from the Rodrigo de Freitas Lagoon (Rio de Janeiro, RJ, Brazil) was mixed with a Gleysol (a typical organic tropical soil) to obtain the following doses: 0, 6, 12, 18, and 24%, where 0% = pure Gleysol. Acute and avoidance bioassays with Eisenia andrei were applied to these mixtures following standard protocols (ISO). Physical, chemical, and mineralogical characterization of the materials and metal determination in the test mixtures were performed to support the interpretations of ecotoxicological data. Metal concentrations in the test mixtures were generally in accordance with the limits defined by Brazilian law. Earthworm mortality was significant in doses ≥ 8% (LC50 = 7.1%), while doses ≥ 2% caused avoidance responses (EC50 = 1.7%, p < 0.05). The salinity in 8% treatment is similar to the salinity levels described by the literature that cause adverse effects on earthworms, suggesting that salinity played a key role in the toxicity. Earthworm biomass increased (p < 0.05) when the organisms were exposed to non-lethal doses, and this is probably due to water bioaccumulation related to high contents of salts. When comparing the toxicity found in this work with data obtained with other tropical soils, one could suppose that Gleysol mineralogy seems to control the bioavailability of salts and metals. The possible formation of technogenic soils (constructed soils) due to land deposition of dredged sediments may potentially compromise natural soil fauna. In this particular case, soil mineralogy, salinity, and metals played a relevant role in the toxicity to earthworms. The development of approaches that can integrate ecotoxicological, ecological, and pedological data is urgent for better understanding the damages associated with the disposal of dredged sediments in tropical lowlands areas.

TECHNOLOGY IMPROVEMENT OF HIGH-DISPERSIVE METALLIC IRON POWDERS BASED ON SEDIMENTS OF IRON REMOVAL STATION

Sediments from iron removal stations are a source of environmental pollution. It is necessary to find effective and eco-friendly methods of sediment disposal. The paper investigates the properties of iron-containing sediment in order to develop a technology for its further utilization. It is shown that sediments from the iron removal station of Velizhansky water intake have a stable chemical composition with about 70 % Fe2O3, and a stable particle size distribution, i.e. 20 μm for ≈ 87 % of particles. These parameters allow developing a flow chart for iron reduction in heated carbon monoxide. The involvement of sediments from iron removal stations in the high-dispersive metallic iron powder production eliminates the sediment deposit at landfills or storage tanks and creates a new raw material base for additive technologies.

Surf zone microbiological water quality following emergency beach nourishment using sediments from a catastrophic debris flow

Urban disaster response requires disposal of complex wastes. This study regards a case wherein high intensity rainfall fell over a remote mountainous area previously burned by wildfire, generating debris flows that devastated a downstream town. Sanitary sewers and homes with septic systems were damaged, releasing human waste into the debris flow field. Contaminated sediments, with their high fecal indicator bacteria (FIB) concentrations, were cleared from public rights-of-way and creek channels by local authorities, then disposed onto distant Goleta Beach for beach nourishment, causing immediate surf zone microbiological water quality exceedances. To determine potential public health threats, disposed sediments and surf zone waters were sampled and analyzed—relative to reference samples of mountain soil and raw sewage—for FIB, pathogens, human (HF183) and other host- (Gull2 TaqMan, and DogBact) associated DNA-based fecal markers, and bacterial community 16S rRNA gene sequences. Approximately 20% of disposed sediment samples contained the HF183 marker; sequencing suggested that all samples were contaminated by sewage. In an initial sediment disposal period, surf zone waters harbored intestinal bacterial sequences that were shared with disposed sediments and sewage. Yet surf zone bacterial communities returned to mostly marine clades within weeks. Taken together, multiple conventional and DNA-based analyses informed this forensic assessment of human waste contamination. In the future, similar analyses could be used earlier in disaster response to guide sediment disposal decisions towards continuously protecting beachgoer health.

Spreading and Deposition of Turbidity Currents: Application to Open-Water Sediment Disposal

Abstract A new two-phase box model is developed in this study for the prediction of a spatially varying turbidity current with sediments on a horizontal bottom. The turbidity current is segmented i...

Effect of change of channel width in the downstream of the check dam on controlling sedimentation in Mrica Reservoir

The increasing sedimentation of Mrica reservoir shows that the sedimentation control has not been effective. The sedimentation control has been made include the disposal of sediments that settle in the reservoir by dredging or flushing. However, the results are not optimal. This is caused by the large volume of sediment entering the reservoir each year. The controlling volume of sediment that goes into the reservoir has also been carried out by conducting a watershed conservation program and building a check dam in the upstream Mrica reservoir. However, the existing check dam is still less effective in controlling sediments, especially suspended load sediments, that are transported in the river. Therefore this study was carried out by adopting the sediment trap concept to deposit sediments that escaped from the check dam. This study simulated changes in the width of the downstream channel of the check dam by three variations using HEC-RAS. There was a width of 20%, 40%, and 60% wider than the initial width. The results showed the effect of changing the channel width on volume sediment deposited. Based on the results of the study, the change in width to wider than the initial width could increase the volume of sediment deposits.

Geospeciation, toxicological evaluation, and hazard assessment of trace elements in superficial and deep sediments.

To evaluate the hazard assessment of dredging and disposal of sediments, an in-depth chemical and toxicological characterization of sediments was carried out in Venice Lagoon. The bioaccessible and mobile concentration of trace elements in superficial and deep sediments (in the Holocene-Pleistocene limit) can deeply affect the quality of the aquatic ecosystem. Geospeciation and total concentration of trace elements in sediment cores were assessed and several toxicological tests were carried out. The indices of contamination (e.g., geochemical accumulation index, Igeo, pollution load index, PLI) and of speciation (individual contamination factor, ICF and global contamination factor, GCF) were evaluated. Factor Analysis (FA) was performed to explore possible significant correlations between toxicity data and sediment chemistry. Results underlined that the total concentration of trace elements cannot adequately assess the hazard, while bioavailability, mobility, and toxicity of trace elements allow a thorough evaluation of the environmental threats. The integration of results from chemical characterization ex ante and toxicity assays will provide for a better sustainable handling and management of sediments.

ВЫБОР ЭФФЕКТИВНОЙ ТЕХНОЛОГИИ УТИЛИЗАЦИИ ОСАДКОВ СТОЧНЫХ ВОД

The article deals with the problem of efficient use of water resources. Factors affecting wastewater treatment and the problem of waste disposal have been identified. It has been established that economic methods should be coordinated with the environmental state in order to rationally manage water resources. The purpose: to reduce the negative environmental burden on water resources by choosing a rational method for the disposal of wastewater sediment. Studies include an analysis of existing methods of wastewater treatment and disposal of sludge. It has been established that the use of the technology for the most complete processing of sewage sludge,utilization of sludge to obtain raw materials for recycling can significantly reduce operating costs. It is accepted as the optimal method to consider the technology of utilization by glazing the sediment, allowing obtaining a granular fraction of raw materials used in the construction industry. An example of the practical implementation of the technology of glazing dehydrated sit cake is presented by a pilot installation at the Shchelkovsite of the sewer treatment plant, as a result of which the amount of wastewater sediment was reduced by almost 25 times.

Environmental availability and oral bioaccessibility of Cd and Pb in anthroposols from dredged river sediments.

Dredging and disposal of sediments onto land sites is a common practice in urban and industrial areas that can present environmental and health risks when the sediments contain metallic elements. The aim of this study was to characterise and study the environmental and toxicological availability of Cd and Pb in anthroposols from dredged river sediments. To do this, 67 surface samples spread over 12 sediment disposal sites in northern France were studied. The results showed substantial heterogeneity for this matrix in terms of physicochemical parameters and contamination degree; however, ascending hierarchical clustering made it possible to classify the samples into eight groups. For each group, the mobile fraction of Cd and Pb was studied using single EDTA extraction, solid-phase distribution was analysed with sequential extractions and toxicological availability was assessed with the oral bioaccessibility test. The results showed that (i) Cd had a higher environmental and toxicological availability than Pb; (ii) this availability depends on the physicochemical characteristics of the matrix; and (iii) it is necessary to take into account the environmental and toxicological availability of contaminants when requalifying these sites in order to propose appropriate management measures. In the first years after sediment disposal, it would appear that the environmental and toxicological availability of Cd and Pb increased (from 52.5 to 71.8% and from 28.9 to 48.9%, respectively, by using EDTA and from 50.2 to 68.5% for Cd with the bioaccessibility test). Further studies would therefore be required to confirm this trend and understand the mechanisms involved.

Best management practices for agricultural nonpoint source pollution: Policy interventions and way forward

AbstractBest management practices (BMPs) are the tools which are adopted to run any activity while inflicting least negative impacts on the surrounding environment. Since, water pollution is one of the most important issues in today's world; it is indispensable to discuss the activities which are deteriorating its quality. Although, a number of treatment technologies and methods are in place for treating the point sources of pollution, there is a need to address nonpoint sources of pollution. There are many successful practices which are capable of curtailing the impacts of nonpoint source pollution, if adopted. In this paper an attempt has been made to evaluate the performance and trade‐offs of various management practices to address the issues of agricultural nonpoint source pollution. Nevertheless, there is a dearth of guiding principles which can pave a way for adoption of these practices. Therefore, an attempt has also been made to explore the aspects of policy formulations along with emphasizing the factors which can lead to adoption/ non‐adoption of such practices.

Macrozoobenthos monitoring in relation to dredged sediment disposal: The case of the Marano and Grado Lagoon (northern Adriatic Sea, Italy)

Coastal lagoons often require direct human intervention, such as dredging and the disposal of dredged material, to maintain the safety and accessibility of navigation channels. Dredging may have short and long-term effects on macrozoobenthic communities. Because they respond relatively quickly to anthropic and natural stress, benthic invertebrates are considered a biological quality element sensu Water Framework Directive 2000/60/CE (WFD) used to assess the ecological status in transitional water such as coastal lagoons.The monitoring of dredged areas and the subsequent comparison to the ecological quality status (EcoQS) sensu WFD in the Marano and Grado Lagoon has revealed that macrozoobenthic communities are slightly unbalanced and tolerant species prevailed. In this naturally stressed environment, the recovery time after the disturbance caused by dredging was three to six months, and richness and diversity were mostly related to the salinity range and distance from sea inlets.