Stabilization and recycling of contaminated marine sediments (original) (raw)
Related papers
Contaminated marine sediments: Waste or resource? An overview of treatment technologies
2016
The continuous stream of sediments dredged, from harbors and waterways, is a considerable environmental issue recognized worldwide. Every year about 200 million of m3 of sediments are dredged only in Europe, over half contaminated and expensive to dispose of. In a vision of sustainability and of circular economy, the proper management of such sediments plays an important role. Therefore, the aim of this study was to critically revise the remediation technologies currently adopted for the suitable reuse, recycling and recovery of contaminated marine sediments (CMS). First of all, the description of the common technologies for the complete removal and/or immobilization of pollutants was realized. Subsequently, potentially technical solutions for marine sediments reuse were discussed. Such re-use or recycling is in line with the European Waste Hierarchy and generates positive environmental impacts. Finally, the research proposes a new approach to the “sediment issue", an ecosustai...
Journal of Cleaner Production, 2018
Contaminated marine sediment management strategies involves in situ and ex situ options for preventing pollutants from re-entering the water column, thus becoming available to benthic organisms and subsequently entering aquatic food chains. These pollution abatement strategies can cause significant secondary environmental impacts which in some cases have been considered to be even higher than the primary ones. This study aims at identifying and quantifying through life cycle assessment (LCA) the environmental impacts of the application of Stabilization/Solidification (S/S) options for the remediation of contaminated marine sediments from the Mar Piccolo in Taranto (Southern Italy). The analysis considers all the stages involved in marine sediments processing (dredging, transport, storage, treatment, safe disposal of the treated sediments) but focuses on several S/S options (4 S/S mixes with cement and 4 mixes with lime). These S/S options were tested at lab scale with different results in immobilizing heavy metals and organic pollutants. The LCA suggests that the ex-situ treatment could contribute to improving the current situation and that the marine sediments S/S operation generates a complex environmental profile which is dominated by the treatment phase, which in turn shows that optimization of this stage could lower these impacts.
2011
The aim of this study was to investigate the effect of cement on the geotechnical properties of contaminated harbor sediments with the use of S/S technology Treatment techniques such as Solidification and Stabilization are becoming increasingly important in the contaminated land sector while they increase awareness of the environmental impact arising from its activities and resulting materials. This study was conducted on harbour sediments derived from Le Havre Harbour (France). The main objectives of this study were to determine the basic geotechnical and chemical characteristics of the harbour sediments, to mix harbour sediments with alcalosynthetic zeolites and ordinary Portland cement (OPC) at 5, 7.5 and 10 percent, by dry weight of the sediments, to determine the compressive strength of the stabilized sediments after curing for 7, 14 and 28 days and 90 days and to examine the leaching characteristics (in accordance with the norm EA NEN 7375:2004 protocol) of the stabilized material with emphasis to alcalosynthetic zeolites Heavy metal concentrations.
Disposal of Sediments for Sustainability: A Review
International Journal of Economy, Energy and Environment, 2017
In the coastal areas, dredging operations are undertaken for creation, draft enhancement and maintenance of navigable channels for port and harbor activities. Dredging may also be performed in rivers or reservoirs for similar reasons. The dredged sediments may be disposed at on-land or oceanic sites. In the recent years, inexpensive ocean dumping is being eliminated as a disposal alternative, causing a crisis in the management of sediment. In construction industry, production of concrete creates heavy demand on the supply of raw materials for cement and also aggregates for concrete. In many locations, habitat restoration and tidal flat creation also generates demand of fine aggregates. It has been observed that at several sites, supply from quarry is not always an economic and feasible option. Sustainable solution to both the aforementioned problems is re-using the sediments from river and ocean in construction industry or bio-diesel production. Various applications attempted in construction industry include those for production of cement, as fine aggregate in concrete, in construction of pavements, in production of lightweight concrete, among others. This article presents a review of approaches employed to recycle dredged sediments in construction industry and biodiesel production.
2014
Reservoir silting is an unavoidable issue. It is estimated that in Italy, the potential rate of silting-up in large reservoirs ranges from 0.1% to 1% in the presence of wooded river basins and intensive agricultural land use, respectively. In medium and small-sized reservoirs, these values vary between 0.3% and 2%. Considering both the types of reservoirs, the annual average loss of storage capacity would be of about 1.59%. In this paper, a management strategy aimed at sediment productive reuse is presented. Particularly, the main engineering outcomes of an extensive experimental program on geopolymer binder synthesis is reported. The case study deals with Occhito reservoir, located in Southern Italy. Clay sediments coming from this silted-up artificial lake were characterized, calcined and activated, by means of a wide set of alkaline activating solutions. The results showed the feasibility of this recovery process, optimizing a few chemical parameters. The possible reuse in building material production (binders, precast concrete, bricks, etc.) represents a relevant sustainable alternative to landfill and other more consolidated practices.
Materials, 2014
Reservoir silting is an unavoidable issue. It is estimated that in Italy, the potential rate of silting-up in large reservoirs ranges from 0.1% to 1% in the presence of wooded river basins and intensive agricultural land use, respectively. In medium and small-sized reservoirs, these values vary between 0.3% and 2%. Considering both the types of reservoirs, the annual average loss of storage capacity would be of about 1.59%. In this paper, a management strategy aimed at sediment productive reuse is presented. Particularly, the main engineering outcomes of an extensive experimental program on geopolymer binder synthesis is reported. The case study deals with Occhito reservoir, located in Southern Italy. Clay sediments coming from this silted-up artificial lake were characterized, calcined and activated, by means of a wide set of alkaline activating solutions. The results showed the feasibility of this recovery process, optimizing a few chemical parameters. The possible reuse in building material production (binders, precast concrete, bricks, etc.) represents a relevant sustainable alternative to landfill and other more consolidated practices.
Clean up of contaminated sediments of the Taranto harbour by stabilization/solidification treatment
Environmental Problems in Coastal Regions VI, 2006
The most widely used procedure for reducing the contamination effects of marine sediments is the dredging and disposal of material in controlled landfills. This method is becoming impracticable because it is increasingly difficult to find adequate space. This study was carried out to design an effective treatment method for heavy metal contaminated sediments using stabilization/solidification (S/S) technology. In particular, experimental investigation on a laboratory scale has been carried out to highlight the effect of inorganic pollutants (copper, nickel and lead) on physico-chemical properties and the leaching behaviour of cement-based solidified materials. To better understanding the S/S process, both artificially spiked and field samples of Taranto harbour sediments contaminated by heavy metals were treated with different kinds of cement and water/cement/sediment ratios. The results of laboratory tests indicated that sediment to be treated requires an increase of the water/cement ratio, due to its remarkable content of fine fraction. A good immobilization of copper, lead and nickel after only seven days of curing, due to high Ph values (8-9) and the percentage of silica (approx. 60 % in weight) in harbour sediment limiting metal leaching from the solidified matrix was observed. In conclusion the cement based S/S technology seems to be effective in treating marine sediments contaminated by heavy metals and is promising for large scale application.
Lime treatment procedures for the reuse of dredged marine sediments
2015
An experimental research has recently been performed for developing an original sediment management and reuse procedure, consisting in the following operations: dredging of the sediments from the seabed, pumping of the dredged soil to the shoreline, reduction of water content by desiccation, addition of lime for stabilisation, placement in the embankment. In the paper some results of the experimental laboratory work carried out to highlight the effectiveness of the procedure have been reported. The suitability of lime treatment has been investigated with particular reference to the high initial water content of the soil. The efficiency of the improvement has been investigated by mechanical testing after short term since lime addition.
Journal of Soils and Sediments, 2009
Background, aim, and scope An innovative stabilization/ solidification (S/S) process using high-performance additivated concrete technology was developed for remediating soil contaminated by metals from abandoned industrial sites. In order to verify the effectiveness of this new ex situ S/S procedure, an area highly contaminated by metallic pollutants (As, Cd, Hg, and Pb), due to the uncontrolled discharge of waste generated from artistic glass production on the island of Murano (Venice, Italy), was selected as a case study. The technique transforms the contaminated soil into an aggregate material suitable for reuse as on-site backfill. This paper reports the main results of the demonstration project performed in collaboration with the local environmental protection agency (ARPAV). Materials and methods An ex situ treatment for brownfield remediation, based on the transformation of contaminated soil into very dense, low porous, and mechanically resistant granular material, was set up and tested. Specific additives (water reducers and superplasticizers) to improve the stabilized material properties were developed and patented. A demonstration plant assembled on the study area to treat 6 m 3 h-1 was then tested. After excavation, the contaminated soil was screened to remove coarse material. The fraction Ø >4 mm (coarse fraction), mainly composed of glass, brick, concrete, and stone debris, was directly reused on site after passing through a washing treatment section. The highly polluted fraction Ø≤4 mm (fine fraction) was treated in the S/S treatment division of the plant (European patent WO/ 2006/097272). The fine fraction was mixed with Portland cement and additives defined on the basis of the high performance concrete technique. The mixture was then granulated in a rolling-plate system. After 28 days curing in an onsite storage area to allow for cement hydration, the stabilized material was monitored before its in situ relocation. The chemical, mechanical, and ecotoxicological reliability and performance of the treatment was checked. Metal leachability was verified according to four leaching test methods: Italian Environmental Ministry Decree (1998), EN 12457 (2002) tout court, amended only with MgSO 4 and, lastly, with artificial sea water. The mechanical properties were measured according to BS (1990) and AASHTO (1999) to obtain the Aggregate Crushing Value
JOURNAL OF ENVIRONMENTAL ENGINEERING AND LANDSCAPE MANAGEMENT, 2015
This study aimed to maximize the utilization of contaminated marine mud and sediment for beneficial reuse by solidification/stabilization (S/S) treatment with cement and pulverized fuel ash (PFA). For the purposes of waste maximization and enhancing the mechanical property of the S/S mixtures, mixing 75% by mass of either contaminated marine mud or sediment with 20% and 5% of cement and PFA, respectively, was found to be the optimal mix design. Their unconfined compressive strengths reached up to 8.32 MPa and 4.47 MPa, respectively. Apart from the mechanical property, according to the U.S.EPA, the TCLP results show that all regulated heavy metals were immobilized to a safe level and are available for engineering application such as fill material. The results of XRD reveal that the formation of CSH gel in the S/S treated mud and sediment is responsible for the strength development and heavy metal immobilization.