Engineering Tools for Environmental Risk Management

4. Risk Reduction Technologies and Case Studies

Katalin Gruiz, Tamás Meggyes, Éva Fenyvesi, Katalin Gruiz, Tamás Meggyes, Éva Fenyvesi

• Publisher: CRC Press
• Year: 2019
• Print ISBN: 9781138001572
• eBook ISBN: 9781317697411
• Edition: 1
• Topic: Ciencias biológicas
• Subtopic: Ciencia medioambiental

The four volumes of the book series "Engineering Tools for Environmental Risk Management" deal with environmental management, assessment & monitoring tools, environmental toxicology and risk reduction technologies. This last volume focuses on engineering solutions usually needed for industrial contaminated sites, where nature's self-remediation is inefficient or too slow. The success of remediation depends on the selection of an increasing number of conventional and innovative methods. This volume classifies the remedial technologies and describes the reactor approach to understand and manage in situ technologies similarly to reactor-based technologies. Technology types include physicochemical, biological or ecological solutions, where near-natural, sustainable remediation has priority.

A special chapter is devoted to natural attenuation, where natural changes can help achieve clean-up objectives. Natural attenuation and biological and ecological remediation establish a serial range of technologies from monitoring only to fully controlled interventions, using ' just' the natural ecosystem or sophisticated artificial living systems. Passive artificial ecosystems and biodegradation-based remediation – in addition to natural attenuation – demonstrate the use of these 'green' technologies and how engineering intervention should be kept at a minimum to limit damage to the environment and create a harmonious ecosystem.

Remediation of sites contaminated with organic substances is analyzed in detail including biological and physicochemical methods.

Comprehensive management of pollution by inorganic contaminants from the mining industry, leaching and bioleaching and acid mine drainage is studied in general and specifically in the case of an abandoned mine in Hungary where the innovative technology of combined chemical and phytostabilization has been applied.

The series of technologies is completed by electrochemical remediation and nanotechnologies.

Monitoring, verification and sustainability analysis of remediation provide a comprehensive overview of the management aspect of environmental risk reduction by remediation.

This book series focuses on the state of knowledge about the environment and its conscious and structured application in environmental engineering, management and decision making.

Chapter 1
Contaminated site remediation: Role and classification of technologies

K. Gruiz

Department of Applied Biotechnology and Food Science, Budapest University of Technology and Economics, Budapest, Hungary

Abstract

The first three chapters of this book aim to identify and classify remediation technologies from the point of view of physicochemical or biological technology and the main physical phases where contaminants occur and should be treated. The remediation principle is based on the reactor approach, which suggests that remediation technologies can be characterized by quantifiable parameters such as mass transport; input and output; physicochemical or biological transformation; and mass balance in the same way as in any engineering technology even if the processes are performed in situ or ex situ.

Planning requires the knowledge of tools, operations, modes of application, expected impacts of the chosen technological parameters and overall efficiencies. All positive and negative impacts, risks and benefits of the technology should be predicted beforehand and confirmed after completion. It is essential to verify the technologies, especially in the case of new technologies, new locations, or unknown geochemical and soil conditions. Environmental, social, and economic risks and benefits should be planned and assessed in order to keep their acceptable balance. Evaluation of the efficiencies and verification of the technology require a multi-skilled team that can select and determine the scope of application and the key parameters and prepare the monitoring plan to acquire the necessary (measured) data for a complex evaluation. The evaluation should cover the direct impacts of processes during their application and the overall impact of the activity on the local environment and its users. In addition to local aspects, the assessment should include watershed-scale and global impacts, and sustainability analysis in the widest context. Potential damage before, during and after remediation (clean-up, rehabilitation) of a small site or a large area may have extensive and long-term impacts on the health of the ecosystem, the human population around the watershed or the global atmosphere, but also on the region’s social, economic, and cultural landscape. The first three chapters give a general overview of remediation technologies and some of them will be discussed in detail. The last chapter will discuss technology verification and sustainability assessment of environmental remediation.

1 Introduction

The term “remediation” means healing the environment, re-establishing a state in which water and soil can fulfill their natural role and provide services for the benefit of mankind. Biogeochemical element and water cycling and provision of a habitat for the ecosystem are essential for accomplishing nature’s role. The services that the environment provides for anthropogenic purposes include water resources, agricultural production and forestry, urban and recreational land uses for special economic, social or cultural needs (for more information see Volume 1 of this book series Gruiz et al., 2014).

According to the engineering approach, environmental remediation is similar to other physicochemical, biological, and agrotechnologies used for the treatment of solid or liquid-phase materials. All liquid-, solid-, or slurry-treatment technologies can be implemented either in the environment in the initial location of the (contaminated) material (i.e. in situ) or in a separate treatment plant in open, semi-open, or closed systems (see also Chapter 2). The management of soil remediation is responsible for harmonizing remediation with spatial planning, selecting the best-fitting technology to the contaminant(s), to the environment, and to the land use; planning and establishing the treatment plant; implementing the technology; and monitoring and controlling technological performance and environmental efficiency. Remedial technologies are extremely versatile: the same soil treatment technology can be used in situ, in a heap or in a built reactor. Whichever is applied, the treated material is reused, typically in the environment, while ensuring the required quality of the products, the remediated soil and water.

One must distinguish between impacts of the technology during and after implementation. During remediation, increased emissions to the atmosphere, groundwater, and surface waters can be expected and emission control technologies should be applied to manage this risk. Post-remediation environmental risks and benefits manifest themselves during the reuse of the treated material or site. Positive and negative impacts of remediation may cover local to water-shed or global scales, immediate and short- to long-term impacts. Planning should pay special attention to technological conditions of in situ and subsurface technologies such as methods applied, processes, risks, and the desired efficiency. Key parameters are to be monitored during implementation. Short-term, long-term, site-specific, and regional or global impacts of an in situ remediation technology may differ depending on the actual environment (sensitivity of land use, urgency of the clean-up) and the interactions between the technology and the environment and contaminants. Well-known, demonstrated and generally verified technologies still do not fully guarantee success because each case is different. The evaluation of the feasibility and sustainability of a technology requires a case-by-case approach and the validation of the predicted values, expected trends and achieved results, i.e. the complete verification of the remediation case.

2 Sustainable Environmental Remediation

Contaminated site management and environmental risk reduction favor site remediation for contaminated land. Prevention does not work “retroactively” and only restrictions such as the prohibition of certain land uses or users may reduce the risk but they cannot improve the environment itself. However, the large number of sites (nearly one million contaminated sites awaiting reclamation in Europe alone) justifies the use of other environmental risk reduction (RR) options, which may include temporary interventions such as restrictions in uses and other preventive measures to control emissions, further risk increases, or land downgrading. Economic aspects such as the necessary expenditure (financial and labor), the importance and benefits of future land uses, or aesthetic issues may also play a role in choosing the most appropriate risk reduction option. On the other hand, remediation may have much wider applications than repairing contaminated land. Contamination is only one possible type of soil or land impairment. Organic matter loss, desertification, salinization, sodification, erosion, landslides, compaction, sealing, and other land takes by human “civilization” cause serious degradations globally. The consequences are fertility decline, loss of ecosystem diversity and low-quality agricultural products, i.e. low-quality food and vulnerable or impaired human health. Soil health is essential for life, food production, human and ecosystem health, and for buffering climate changes and other adverse impacts such as droughts and floods. Therefore, it is important that soil remediation maintains soil quality, and continuously compensates for soil degradation, humus loss, and nutrient decline – including not only the lack of macronutrients but also mezo- and microelements and other biologically active molecules.

The 2012 report of the Joint Research Centre “State of the Soil in Europe” (JRC, 2012) mentions nearly 3.5 million potentially contaminated sites in Europe alone, while EEA (EEA, 2015 a) cited 1 million identified and 2.5 million estimated contaminated sites in total in 2015. The origins of contamination are waste disposal and treatment (40% of the sites) and industry and commerce (35% of the sites). These sites need detailed investigation and in some cases remediation as well. The number of remedied sites is about 100,000 across the EU, i.e. 4% of the estimated number to be managed. The specific number of potentially contaminated sites per 1000 people is two to four in the EU (EEA, 2015 b; ESDAC, 2013a,b,c).

US Superfund (2018) applies a practical approach and maintains a National Priorities List (NPL, 2017) with a manageable number of priority sites (identified as the most urgent among the total). It currently lists 1337 sites: remediation has been carried out at 1189 of them since 1983 and 392 have been deleted from the list (NPL Action, 2017).

Remediation includes the reduction of physical (erosion, landslide), chemical (ignition, explosion, and corrosion), ecological (aquatic and terrestrial ecosystem), and human health risks in all environmental compartments, i.e. air, surface water and sediments, and soil and subsurface water. When dealing with these risks, the aim of remediation is to re-establish a good quality of the environment with healthy biological diversity and activity and safe use for humans. The ethics behind remediation involves restoring natural diversity and the quality of water and soil over the long term, as well as protecting natural resources and ecological services from adverse anthropological impacts. A feasible solution should achieve optimal efficiency and harmony between future land uses and the selected remediation technology. The management team needs exhaustive information on the nature of deterioration, the site, short- and long-term spatial plans, and on the best available technologies.

Compared to the preparatory work and the necessary knowledge, remediation technologies (equipment and processes) are rather simple in most cases and can be adopted from other industries such as mining, agriculture, and from nature itself.

Reducing the risk posed by contaminants in soil includes the treatment of all physical phases: soil air (soil gas and vapor), soil water (moisture, pore water, groundwater, seepage water, leachate), and solid...

Table of contents

• Cover
• Half Title
• Title
• Copyright
• Table of contents
• Preface
• List of abbreviations
• About the editors
• 1 Contaminated site remediation: role and classification of technologies
• 2 In situ soil remediation: the reactor approach
• 3 Natural attenuation in contaminated soil remediation
• 4 Ecoengineering tools: passive artificial ecosystems
• 5 Biodegradation-based remediation - overview and case studies
• 6 Traditional and innovative methods for physical and chemical remediation of soil contaminated with organic contaminants
• 7 Leaching, bioleaching and acid mine drainage case study
• 8 Remediation technologies for metal-contaminated soil and sediment – an overview and a case study of combined chemical and phytostabilization
• 9 Electrochemical remediation for contaminated soils, sediments and groundwater
• 10 Elemental iron and other nanotechnologies for soil remediation
• 11 Planning, monitoring, verification and sustainability of soil remediation
• Subject index
• Series Page