Environmental assessment on electrokinetic remediation of multimetal-contaminated site: a case study

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  • RESEARCH ARTICLE

    Environmental assessment on electrokinetic remediationof multimetal-contaminated site: a case study

    Do-Hyung Kim & Jong-Chan Yoo & Bo-Ram Hwang &Jung-Seok Yang & Kitae Baek

    Received: 4 December 2013 /Accepted: 23 January 2014 /Published online: 11 February 2014# Springer-Verlag Berlin Heidelberg 2014

    Abstract In this study, an environmental assessment on anelectrokinetic (EK) system for the remediation of a multimetal-contaminated real site was conducted using a green and sus-tainable remediation (GSR) tool. The entire EK process wasclassified into major four phases consisting of remedial inves-tigations (RIs), remedial action construction (RAC), remedialaction operation (RAO), and long-term monitoring (LTM) forenvironmental assessment. The environmental footprints, in-cluding greenhouse gas (GHG) emissions, total energy used,air emissions of criteria pollutants, such as NOx, SOx, andPM10, and water consumption, were calculated, and the rela-tive contribution in each phase was analyzed in the environ-mental assessment. In the RAC phase, the relative contributionof the GHG emissions, total energy used, and PM10 emissionswere 77.3, 67.6, and 70.4 %, respectively, which were higherthan those of the other phases because the material consump-tion and equipment used for system construction were high. Inthe RAO phase, the relative contributions of water consump-tion and NOx and SOx emissions were 94.7, 85.2, and 91.0 %,respectively, which were higher than those of the other phases,

    because the water and electricity consumption required forsystem operation was high. In the RIs and LTM phases, theenvironmental footprints were negligible because the materialand energy consumption was less. In conclusion, the consum-able materials and electrical energy consumptionmight be veryimportant for GSR in the EK remediation process, because theproduction of consumable materials and electrical energy con-sumption highly affects the GHG emissions, total energy used,and air emissions such as NOx and SOx.

    Keywords Environmental assessment . Electrokineticremediation .Multimetal-contaminated site . Green andsustainable remediation

    Introduction

    The rapid industrial development which has taken place overthe past few decades has caused many sites in Korea to becomecontaminated. Because of the serious effect that these sites haveon human health and ecosystems, it is necessary to remediate orclean them up in order to reduce this risk. Therefore, the KoreanMinistry of Environment (MOE) established the Soil Environ-ment Conservation Act (SECA) in 1995 to protect soil qualityand regulate hazardous pollutants (MOE 1995). The KoreanMOE reported that a total of 434 contaminated sites wereremediated during the period of 20002006 (MOE 2007). Inthe first 10 years, most remediation activities were carried outfor the purpose of cleaning up petroleum-contaminated sites.However, the proportion of metal-contaminated sites has in-creased gradually since 2006, and the Korean standard methodfor metal was revised based on the total content extracted byaqua regia in 2009. Tomeet the requirements posed by this newregulation level, that is, to reduce the total content of metals inthe soil, separation techniques such as soil washing and elec-trokinetic remediation have been applied to remove the metalsfrom the soil. Even though soil washing is a common choice formetal-contaminated sites in Korea, several researchers have

    Responsible editor: Philippe Garrigues

    D.

  • focused on the removal of various pollutants using electroki-netic remediation for contaminated sites, as laboratory and pilotscale and field applications (Acar et al. 1995; Amrate et al.2005; Cho et al. 2009; Cho et al. 2010; Gent et al. 2004; Kimet al. 2013a; Kim et al. 2011; Kim et al. 2009; Kim et al. 2012;Kim et al. 2013c; Lee et al. 2011; Ryu et al. 2010; Zhou et al.2006). Even though the electrokinetic (EK) technique canremove heavy metals from the soil, this remedial activity mightnegatively affect the environment. For instance, the processconsumes electrical energy during system operation, and elec-trode materials and enhancing chemicals are generally used forsystem installation and operation. The production of materials/chemicals, generation of electrical energy, and consumption ofnatural resources causes the discharge of toxic gases and envi-ronmental pollutants. Therefore, it is necessary to evaluate theenvironmental net footprint of these remediation techniques.

    The technical, environmental, and economic parametersshould be comprehensively considered for the selection ofthe remediation actions of the contaminated sites (Lemming2010). However, so far in Korea, remediation projects havebeen carried out to meet the regulation levels within limitedcosts without consideration of the environmental impactsduring these activities. Nowadays, climate change and theenergy crisis have spurred a great deal of interest in greenand sustainable remediation (GSR), which achieves cleanupwhile minimizing the emissions (USEPA 2008a, b). Environ-mental assessment is a technique to evaluate the environmen-tal footprints and benefits during remediation activity basedon life-cycle assessment (LCA), which is well known for thequantitative analysis of the environmental impacts of a prod-uct or process through its whole life cycle (Lemming et al.2010a; Morais and Delerue-Matos 2010; Sur et al. 2004).Several researchers made an environmental assessment ofremediation technologies using LCA, focusing on organicpollutants (Bayer and Finkel 2006; Cadotte et al. 2007;Harbottle et al. 2007; Higgins and Olson 2009; Hu et al.2011; Lemming et al. 2010b; Sanscartier et al. 2010; Suerand Andersson-Skld 2011; Toffoletto et al. 2005; Volkweinet al. 1999) and heavy metals (Page et al. 1999). Volkweinet al. (1999) reported an environmental assessment of the on-site remediation for a PAHs contaminated site using LCA.Cadotte et al. (2007) conducted an environmental assessmenton several remedial options such as bioslurping, bioventing,and biosparging for the cleanup of a petroleum-contaminatedsite including light nonaqueous phase liquid, soil, and ground-water using LCA. Page et al. (1999) reported a case study onremediation options comparedwith excavation and landfill fora Pb-contaminated site using LCA. However, most studies onenvironmental assessment focused on the technology for or-ganic pollutants, while there have been fewer studies on thetechnology for heavy metals. Furthermore, environmentalassessment on electrokinetic remediation (EKR) has not beenaccomplished. In this study, a pilot EK system was applied to

    remediate a multimetal-contaminated site, and we assessed theenvironmental impacts on the whole process of an EK systembased on the operational data using a GSR tool. The purposeof this research is to analyze the environmental footprint,calculate the relative contribution of each phase on the EKsystem at a multimetal-contaminated site, and to providestrategies for GSR based on the evaluation results.

    Materials and methods

    Description of a pilot scale electrokinetic remediation

    The environmental assessment was conducted using an in situpilot scale EK treatment. Figure 1 shows a schematic of EKprocess used in this study. A system was installed situated at369 Jangam-ri within 1 km of the Janghang refinery plantapproximately 150 km from Seoul, South Korea. An in situEKR system to treat a multimetal-contaminated site wasinstalled as a pilot-scale system. The area of the site wasapproximately 60 m2 (6 m [W]10 m [L]), and its volumewas 90 m3 (1.5 m [H]). The entire EK system consists ofmajor four parts for the electrode, electrolyte, circulation, andpower supply compartments. The detail description of pilotEK system in this study was summarized in Table 1. The totalduration for the EK system including site investigation andpreparation, system installation, operation, maintenance, mon-itoring, dismantlement, and site closure was approximately12 months, and the duration of the EK system used for theactual operation was approximately 11 months.

    Cathode

    Tank

    Anode

    Tank

    Anode

    Tank

    Cathode

    Tank

    Inlet Pump

    Outlet

    9.6m

    6.25m

    Power supply &

    Monitoring system

    Circulation

    AnodeCathode

    Fig. 1 Schematic of electrokinetic remediation system

    6752 Environ Sci Pollut Res (2014) 21:67516758

  • The site was highly contaminated with arsenic (As), copper(Cu), and lead (Pb), and especially, the concentration of Aswas approximately 150 mg/kg, which is six times higher thanthe regulatory level (25 mg/kg) in South Korea.

    Environmental assessment

    The environmental assessment was conducted on an EK pro-cess using a GSR tool including goal and scope definition,data collection and analysis, and output assessment afterconducting EK field application to a real site. Then, wesuggested strategies for GSR based on the evaluation results.In this study, we analyzed the environmental impacts of theremedial activities using activity-based SiteWise ver. 2 pro-gram. SiteWise is designed to evaluate remediation technol-ogy and to compare alternative technologies based on theirenvironmental footprints (Battle Memorial Institute 2011).For the analysis, the whole activity was separated into fourphases: remedial investigations (RIs); remedial action con-struction (RAC); remedial action operation (RAO), andlong-term monitoring (LTM). The total footprints were ana-lyzed by calculating the footprints of each phase separately.

    Goal and scope definition

    The goal of this studywas to assess the environmental impacts onan in situ EK process in the remediation of an As-, Cu-, and Pb-contaminated site and calculate the relative contribution for theenvironmental footprint of each phase in the

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