Use of Life Cycle Assessments To Evaluate the Environmental Footprint of Contaminated Sediment Remediation

Abstract

Ecological and human risks often drive the selection of remedial alternatives for contaminated sediments. Traditional human and ecological risk assessment (HERA) includes assessing risk for benthic organisms and aquatic fauna associated with exposure to contaminated sediments before and after remediation as well as risk for human exposure but does not consider the environmental footprint associated with implementing remedial alternatives. Assessment of environmental effects over the whole life cycle (i.e., Life Cycle Assessment, LCA) could complement HERA and help in selecting the most appropriate sediment management alternative. Even though LCA has been developed and applied in multiple environmental management cases, applications to contaminated sediments and marine ecosystems are in general less frequent. This paper implements LCA methodology for the case of the polychlorinated dibenzo-p-dioxins and -furans (PCDD/F)-contaminated Grenland fjord in Norway. LCA was applied to investigate the environmental footprint of different active and passive thin-layer capping alternatives as compared to natural recovery. The results showed that capping was preferable to natural recovery when analysis is limited to effects related to the site contamination. Incorporation of impacts related to the use of resources and energy during the implementation of a thin layer cap increase the environmental footprint by over 1 order of magnitude, making capping inferior to the natural recovery alternative. Use of biomass-derived activated carbon, where carbon dioxide is sequestered during the production process, reduces the overall environmental impact to that of natural recovery. The results from this study show that LCA may be a valuable tool for assessing the environmental footprint of sediment remediation projects and for sustainable sediment management.

Sorption of hydrophobic organic compounds to a diverse suite of carbonaceous materials with emphasis on biochar

“…However, our results showed that strong sorption may also be achieved without activation but with the use of a high pyrolysis temperature (>700 C). In cases where nonactivated CM sorb almost as strongly as activated ones they may be preferential since they avoid energy input involved in the activation process, and are more favorable in the context of a complete life cycle (Sparrevik et al, 2011). However, it should be noted that the observed high sorption strength for some CM cannot be solely related to CM pyrolysis temperature since pyrolysis results in a series of complex reactions leading to less hydrophilic and more highly aromatic structure, and increased surface area and an increase in pore volume as pyrolysis proceeds.…”

Kinetic Modelling and Half Life Study of Adsorptive Bioremediation of Soil Artificially Contaminated With Bonny Light Crude Oil

“…Activated or nonactivated charcoals have been shown to reduce phytotoxicity of many herbicide residues and other chemicals in agricultural soils [Strek et al, 1981;Mukhin et al, 1995], reduce hydrophobic organic pollutant leaching , pollutant loss to the atmosphere [Bushnaf et al, 2011], and uptake from soil by plants [Vasilyeva et al, 2010;Jakob et al, 2012], and earthworms [Langlois et al, 2011]. However, replacing coalderived activated carbon with biochar is motivated by the successful use of coal-derived activated charcoals for the in-situ sequestration of hydrophobic organic compounds (HOCs) [Ghosh et al, 2011] and thus would reduce economic costs and improve the sustainability of remediation efforts [Sparrevik et al, 2011].…”

Sustainable decision making under uncertainty: a case study in dredged material management

“…This is in conformity with [7], stating that a certain degree of data quantity and accuracy are to be fulfilled for SMAA application. Dorini et al [3] and Sparrevik et al [32] suggest use of preliminary life cycle assessments (LCA) and economic analysis. A similar method of incorporating LCA results in MCDA has been applied by Prado-Lopez et al [33].…”