Site Remediation Technologies Research Articles

Taking into account the relief variability when creating an industrial eco testing site and reclamation and remediation technologies

Taking into account the relief variability when creating an industrial eco testing site and reclamation and remediation technologies

Ex-situ phytoextraction using Pteris vittata as a sustainable way to protect soil resource

Chemical industrial sites are potential land resources for urban construction, but the high concentration of heavy metals in soil restricts their timely redevelopment. Remediation treatment must be performed before the reutilization of these sites. Aiming to investigate the potential of Pteris vittata to remove arsenic (As) from an As-contaminated chemical industrial site, a 16-month ex-situ field experiment was conducted to monitor the dynamics of growth and As uptake of P. vittata. The shoot (pinnae and petiole) biomass increased linearly with the extension of time, and reached 1342 g m−2 at the time of ∼16 months after transplantation. The shoot As concentration in pinnae showed a “large increase followed by small decrease” tendency and reached its highest value of 2550 mg kg−1 at the time of ∼10 months after transplantation. Compared with the control that removed 5.1 kg As ha −1, the addition of potassium dihydrogen phosphate at the dose of 600 mg (P2O5) kg−1 or ammonium dihydrogen phosphate at the dose of 300 mg (P2O5) kg−1 increased the As removal by P. vittata to ∼13.0 kg ha−1. The total cost of ex-situ phytoremediation was 41.6 US$ t−1, being ∼67% lower than that of common site remediation technologies such as soil washing. Ex-situ phytoremediation is suggested to enable a timely re-development of land resource and a sustainable protection of soil resource.

Choice of Remediation Technology for a Contaminated Soil by 1,2-Dichloroethane (DCA)

In Mexico, there are 635 sites contaminated by hazardous waste, due to the fact that a few years ago there was no legislation to support and guarantee environmental protection. This led to decades of contamination of soils and bodies of water. In the following case study, landfills were identified where 1,2-dichloroethane was stored, generating contaminated soil in this location, even affecting subway water bodies. The aim of this work is to identify the technologies for the remediation of contaminated soils, taking into account the affected site, the characteristics of the residue, costs and time, in order to determine the most effective and ideal technology. The Federal Remediation Technologies Roundtable (FRTR) will be considered as the counterpart for the selection of treatment technologies, published by the Remediation Bureau. The best technology for site remediation is "Soil Vapor Extraction", being the most ideal and efficient in terms of time and cost, and generating a high impact remediation outcome. The counterpart (FRTR) is considered to be a support tool that provides the most appropriate technologies for the remediation of a contaminated site.

Development and Application of an Integrated Site Remediation Technology Mix Method Based on Site Contaminant Distribution Characteristics

Millions of contaminated sites worldwide need to be remediated to protect the environment and human health. Although numerous remediation technologies have been developed, selecting optimal technologies is challenging. Several multiple criteria decision-making methods for screening the optimal remediation technology have been proposed, but they mostly focus on a specific area rather than the whole contaminated site. In recent years, the “contamination source control—process blocking—in situ remediation” technology mix model has gradually gained high appreciation. Nevertheless, the screening of technologies within each chain of this model relies heavily on arbitrary personal experience. To avoid such arbitrariness, a petroleum-contaminated site containing light non-aqueous phase liquids (LNAPLs) was used as an example, and a scientific screening and combination procedure was developed in this study by considering the distribution characteristics of contaminants. Through the procedure, a technology mix, which includes institutional control, risk monitoring, emergency response, multiphase extraction, interception ditch, monitoring of natural attenuation, hydrodynamic control, as well as some alternative technologies, was found, aiming at different locations and strata. The clear spatial relationship concept promises to enhance the effectiveness of contaminated site remediation. The proposed method only gave us a technical framework and should be tested and enriched in future studies.

Immobilizing lead and copper in aqueous solution using microbial- and enzyme-induced carbonate precipitation.

Inappropriate irrigation could trigger migration of heavy metals into surrounding environments, causing their accumulation and a serious threat to human central nervous system. Traditional site remediation technologies are criticized because they are time-consuming and featured with high risk of secondary pollution. In the past few years, the microbial-induced carbonate precipitation (MICP) is considered as an alternative to traditional technologies due to its easy maneuverability. The enzyme-induced carbonate precipitate (EICP) has attracted attention because bacterial cultivation is not required prior to catalyzing urea hydrolysis. This study compared the performance of lead (Pb) and copper (Cu) remediation using MICP and EICP respectively. The effect of the degree of urea hydrolysis, mass and species of carbonate precipitation, and chemical and thermodynamic properties of carbonates on the remediation efficiency was investigated. Results indicated that ammonium ion (NH4 +) concentration reduced with the increase in lead ion (Pb2+) or copper ion (Cu2+) concentration, and for a given Pb2+ or Cu2+ concentration, it was much higher under MICP than EICP. Further, the remediation efficiency against Cu2+ is approximately zero, which is way below that against Pb2+ (approximately 100%). The Cu2+ toxicity denatured and even inactivated the urease, reducing the degree of urea hydrolysis and the remediation efficiency. Moreover, the reduction in the remediation efficiency against Pb2+ and Cu2+ appeared to be due to the precipitations of cotunnite and atacamite respectively. Their chemical and thermodynamic properties were not as good as calcite, cerussite, phosgenite, and malachite. The findings shed light on the underlying mechanism affecting the remediation efficiency against Pb2+ and Cu2+.

Research progress of bio-slurry remediation technology for organic contaminated soil.

Bio-slurry remediation technology, as a controllable bioremediation method, has the significant advantage of high remediation efficiency and can effectively solve the problems of high energy consumption and secondary pollution of traditional organic pollution site remediation technology. To further promote the application of this technology in the remediation of organically polluted soil, this paper summarizes the importance and advantages of bio-slurry remediation technology compared with traditional soil remediation technologies (physical, chemical, and biological). It introduces the technical infrastructure and its technological processes. Then, various factors that may affect its remediation performance are discussed. By analyzing the applications of this technology to the remediation of typical organic pollutant-(polycyclic aromatic hydrocarbons(PAHs), polychlorinated biphenyls(PCBs), total petroleum hydrocarbons(TPH), and pesticide) contaminated sites, the following key features of this remediation technology are summarised: (1) the technology has a wide range of applications and can be used in a versatile way in the remediation projects of various types of organic-contaminated soil sites such as in clay, sand, and high organic matter content soil; (2) the technology is highly controllable. Adjusting environmental parameters and operational conditions, such as nutrients, organic carbon sources (bio-stimulation), inoculants (bio-augmentation), water-to-soil ratio, etc., can control the remediation process, thus improving the restoration performance. To sum up, this bio-slurry remediation technology is an efficient, controllable and green soil remediation technology that has broad application prospects.

Investigation on stabilization/solidification characteristics of lead-contaminated soil using innovative composite model of cement and soda residue

The cement solidification/stabilization method of heavy metal contaminated soils has been promoted in engineering practice and applied on a large scale for site remediation, but it still reveals some scientific problems in the current complex and variable global extreme climate. To solve these problems, this study used waste soda residue as a composite additive, and established an innovative composite model (cement-soda) to remediate lead-contaminated soil. The innovative composite model for unconfined compressive strength (UCS) and toxic leaching properties under different conditions were investigated As well as curing and leaching mechanisms are discussed, and future industrial practice was evaluated. The results showed that the addition of soda residue improved the early (20 days) UCS of the composite curing agent for lead-contaminated soil by an average of 23.1% MPa. The UCS strength was 0.96 MPa, which was the maximum when the percentage of soda residue composite was 40%. The concentration of Pb2+ in the leachate of the cement-soda residue (CSH) composite curing agent was greatly reduced (average 3.28 times) compared with that of a single cement in the same situation, with an average leached Pb2+ concentration of 1.87 mg·L−1. This finding indicates that the addition of alkali residue improved the curing effect. The curing mechanism was divided into four steps, mainly a complex physicochemical reaction between the CSH composite and soil particles. The leaching mechanism of CSH to aqueous solution is mainly the consumption of acid ions by alkaline substances. Collectively, this study will provide scientific data to support potential lead-containing soil in site remediation technologies and future large-scale engineering applications.

Environmental geotechnics: challenges and opportunities in the post-Covid-19 world

The outbreak of the coronavirus disease 2019 (Covid-19) pandemic not only has created a health crisis across the world but is also expected to impact negatively the global economy and societies at a scale that is maybe larger than that of the 2008 financial crisis. Simultaneously, it has inevitably exerted many negative consequences on the geoenvironment on which human beings depend. The current paper articulates the role of environmental geotechnics in elucidating and mitigating the effects of the current pandemic. It is the belief of all authors that the Covid-19 pandemic presents not only significant challenges but also opportunities for the development of the environmental geotechnics field. This discipline should make full use of geoenvironmental researchers’ and engineers’ professional skills and expertise to look for development opportunities from this crisis, to highlight the irreplaceable position of the discipline in the global fight against pandemics and to contribute to the health and prosperity of communities, to serve humankind better. In order to reach this goal while taking into account the specificity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the uncertainty of its environmental effects, it is believed that more emphasis should be placed on the following research directions: pathogen–soil interactions; isolation and remediation technologies for pathogen-contaminated sites; new materials for pathogen-contaminated soil; recycling and safe disposal of medical wastes; quantification of uncertainty in geoenvironmental and epidemiological problems; emerging technologies and adaptation strategies in civil, geotechnical and geoenvironmental infrastructures; pandemic-induced environmental risk management; and modelling of pathogen transport and fate in geoenvironment, among others. Moreover, Covid-19 has made it clear to the environmental geotechnics community the importance of urgent international co-operation and of multidisciplinary research actions that must extend to a broad range of scientific fields, including medical and public health disciplines, in order to meet the complexities posed by the Covid-19 pandemic.

The Status and Prospect of Decommissioning Technology Development at KAERI

The current status and prospect of decommissioning technology development at KAERI are reviewed here. Specifically, this review focuses on four key technologies: decontamination, remote dismantling, decommissioning waste treatments, and site remediation. The decontamination technologies described are component decontamination and system decontamination. A cutting method and a remote handling method together with a decommissioning simulation are described as remote dismantling technologies. Although there are various types of radioactive waste generated by decommissioning activities, this review focuses on the major types of waste, such as metal waste, concrete waste, and soil waste together with certain special types, such as high-level and high-salt liquid waste, organic mixed waste, and uranium complex waste, which are known to be difficult to treat. Finally, in a site remediation technology review, a measurement and safety evaluation related to site reuse and a site remediation technique are described.

Interactions and Reductive Reactivity in Ternary Mixtures of Fe(II), Goethite, and Phthalic Acid Based on a Combined Experimental and Modeling Approach.

The interactions between organic ligands, Fe(II), and iron oxides are important in biogeochemical redox processes. The effect of phthalic acid (PHA) on the reductive reactivity of Fe(II) associated with goethite was examined using batch adsorption and kinetic studies, attenuated total reflectance?Fourier transform infrared spectroscopy (ATR?FTIR), and surface complexation modeling (SCM). PHA significantly inhibited the reductive reactivity of Fe(II)/goethite, as quantified by the pseudo-first-order reduction rate constants ( k) of p-cyanonitrobenzene. The k value decreased from 1.68 ? 0.03 to 0.338 ? 0.14 h?1 at pH 6.0 as the PHA concentration increased from 0 to 1000 ?M. The effects of the co-adsorption of Fe(II) and PHA onto goethite were then investigated to study the inhibition mechanism. The adsorption experiments showed that Fe(II) slightly enhanced PHA adsorption, whereas PHA did not affect Fe(II) adsorption, suggesting that the inhibition was not due to different amounts of Fe(II) adsorbed. The ATR?FTIR spectra of the adsorbed PHA in the ternary mixtures demonstrated that the major surface species was outer-sphere species, with minor inner-sphere complexes formed. SCM results showed that the presence of PHA (L) led to the formation of a type A ternary species ((?FeOFe+)2???L2?) on the goethite surface, decreasing the abundance of the reactive species (?FeOFeOH). Moreover, the adsorption of PHA on the surface of goethite might block the reactive sites and inhibit the electron transfer between Fe(II) and goethite, thus decreasing the reactivity. Overall, these findings provided new insights into the reaction mechanisms of surface-adsorbed Fe(II), which will facilitate the development of new technologies for site remediation and more accurate risk assessment.

Application and Selection of Remediation Technology for OCPs-Contaminated Sites by Decision-Making Methods.

The production and use of organochlorine pesticides (OCPs) for agricultural and industrial applications result in high levels of their residues, posing a significant risk to environmental and human health. At present, there are many techniques for OCP-contaminated soil remediation. However, the remediation of contaminated sites may suffer from a series of problems, such as a long recovery cycle, high costs, and secondary pollution, all of which could affect land redevelopment and reuse. Therefore, the selection of an appropriate technology is crucial for contaminated sites. In order to improve and support decision-making for the selection of remediation techniques, we provide a decision-making strategy for the screening of remediation techniques of OCP-contaminated sites. The screening procedure is proposed based on combining the analytic hierarchy process (AHP) and the technique for order preference by similarity to ideal solution (TOPSIS). The screening indexes include economic indicator, environmental indicator, and technical indicator. The assessment results show that co-processing in cement kiln obtained the highest overall score and was thus considered to be the most sustainable option. This suggested remediation technology was similar to the practical remediation project, indicating that the screening method could be applied for the selection of remediation technologies for sites contaminated with persistent organic pollutants.

Phytoremediation of Lead and Chromium Contaminated Soil Improves with the Endogenous Phenolics and Proline Production in Parthenium, Cannabis, Euphorbia, and Rumex Species

Phytoremediation is the most promising and emerging technology for remediation of metal-contaminated sites. The aim of the current research was to investigate the metals accumulation potential of four weed species i.e., Parthenium, Cannabis, Euphorbia, and Rumex species. The endogenous free proline, total phenolic, carotenoids, and chlorophyll contents were assessed under metals stress and correlated with metals accumulation in plants. Plants of each species were allowed to grow in reference (uncontaminated) soil and other group on industrial effluent-contaminated soil under natural environment. Phytoextraction potentials of these plants were evaluated for removal of lead (Pb) and chromium (Cr). The heavy metal concentration in plant parts was analyzed by atomic absorption spectrophotometer. Varied accumulation of metals was found among different weed species. Moreover, metal accumulation was different within plant tissues i.e., roots, leaves, and stem. Cannabis and Parthenium showed bio-concentration BCF > 1 for Pb, reflecting their high metal accumulation potential and both plants were found superior than Rumex and Euphorbia for Cr accumulation. The endogenous free proline and phenolic contents showed significantly positive correlation with Pb accumulation in four plants i.e., Parthenium (R2 = 0.977, R2 = 0.9996), Cannabis (R2 = 0.9924, R2 = 0.9999), Euporbia (R2 = 0.9992, R2 = 0.9832), Rumex (R2 = 0.6033, R2 = 0.8272) respectively. Similarly, Cr accumulation in plants showed significantly positive correlation with proline and phenolic but the BCF ˂ 1.The chlorophyll and carotenoids contents in all plants negatively correlated with Pb and Cr concentration.

镉污染场地修复技术综述

镉污染场地修复技术综述

Contaminated Site Management and Remediation Technologies

Contaminated Site Management and Remediation Technologies

Восстановление деревянной балки импрегнированием полимерной композицией на основе эпоксидной смолы

This paper proposes a method of restoration of wooden structures by impregnating polymer composition based on epoxy resin, locally weakened destruction. Objective - research and development of technology for site remediation of wooden structures with areas of locally de-graded wood. We analyzed the causes of the destruction of wooden building structures. The pa-per sets out the methodology and the engineering based on the example of a wooden beam, the destruction of locally weakened in the core zone. Engineering calculations were confirmed by numerical experiments carried out in the program complex "Lira 9.6".

Review of Nanotechnology for Soil and Groundwater Remediation: Brazilian Perspectives

The soil remediation field is still in de- velopment in Brazil. Currently, it is not known how many contaminated sites exist across the country; however, due to the country's large size and its extensive urbanization and industrialization, it can be postulated that the number of contami- nated sites must be very high. To remediate these sites, new sustainable technologies should be iden- tified and evaluated. A technology that was born in the 1990s in the USA, and has been fairly investigated, is the use of nanoparticles (NPs) to degrade contaminants in soils and groundwater. This study aims to present a bibliographic review of nanotechnology application to remediation of soils and groundwater, as well as assess the po- tential of conducting research in this field in Brazil. This paper first presents an overview of the number of contaminated areas identified in the USA and Europe. The basic concepts of nanomaterials followed by classification, synthesis, and characterization of nanomaterials are ex- plained. The main types of contaminants for which the technique was already applied as well as the chemical reactions between them and NPs are pre- sented. The issues related to delivery and migra- tion of NPs in the porous media is discussed. Concerns regarding the toxicity of nanomaterials are discussed. The in situ applications of nanomaterials for contaminated site remediation are presented. It is concluded that the issues in- volving remediation of soils and groundwater are site specific and it is not possible to directly transfer knowledge gained from sedimentary soils of temperate climates for residual soils found in tropical and subtropical climate regions. The research on nano- technology for site remediation in Brazil has just begun, and more efforts are required from the technical and academic professionals to develop nanotechnology as practical technology for the remediation of contaminat- ed sites.

Improving Objectives for Cleanup Sites

In 1976, the discovery of the Love Canal Superfund Site in New York thrust environmental cleanups into the forefront of the national conscience and essentially launched the remediation industry. Since then, vast efforts have been devoted to improving site remediation. Despite the attention given to key subject areas, such as site characterization, risk assessment, and remediation technologies, relatively little attention has been given to the objectives set forth for conducting cleanups, and they have generally not been rigorously evaluated in the literature. Several of the more common objectives for remediation projects are discussed. © 2014 Wiley Periodicals, Inc.

Co-contamination of water with chlorinated hydrocarbons and heavy metals: challenges and current bioremediation strategies

Chlorinated hydrocarbons can cause serious environmental and human health problems as a result of their bioaccumulation, persistence and toxicity. Improper disposal practices or accidental spills of these compounds have made them common contaminants of soil and groundwater. Bioremediation is a promising technology for remediation of sites contaminated with chlorinated hydrocarbons. However, sites co-contaminated with heavy metal pollutants can be a problem since heavy metals can adversely affect potentially important biodegradation processes of the microorganisms. These effects include extended acclimation periods, reduced biodegradation rates, and failure of target compound biodegradation. Remediation of sites co-contaminated with chlorinated organic compounds and toxic metals is challenging, as the two components often must be treated differently. Recent approaches to increasing biodegradation of organic compounds in the presence of heavy metals include the use of dual bioaugmentation; involving the utilization of heavy metal-resistant bacteria in conjunction with an organic-degrading bacterium. The use of zero-valent irons as a novel reductant, cyclodextrin as a complexing agent, renewable agricultural biosorbents as adsorbents, biosurfactants that act as chelators of the co-contaminants and phytoremediation approaches that utilize plants for the remediation of organic and inorganic compounds have also been reported. This review provides an overview of the problems associated with co-contamination of sites with chlorinated organics and heavy metals, the current strategies being employed to remediate such sites and the challenges involved.

Studies on degradation behavior and simulate remediation to contaminated soil of endosulfan

Endosulfan is a highly toxic organochlorine pesticide. A large number of endosulfan has been produced over the past years in China. Thus the remediation technologies for endosulfan-contaminated sites are urgently needed. The degradation behavior of endosulfan in the soil was investigated under controlled laboratory conditions. The conditions of bio-pile and chemical remediation for endosulfan-contaminated soil were studied by using simulated bio-piles. The results indicate that a-endosulfan is partially transformed into b-endosulfan in the soil medium. The microbial degradation of endosulfan is aerobical. The degradation of endosulfan is enhanced by adding straw, green manure, and using proper ventilation, but inhibited by adding EM fungi, glucose, ammonium nitrate, or fertilizer. Alkaline condition is favorable the rapid degradation of endosulfan. Therefore, adding lime to the contaminated soil is a highly effective method of chemical remediation.

Horizontal Directional Drilling: A Green and Sustainable Technology for Site Remediation

Sustainability has become an important factor in the selection of remedies to clean up contaminated sites. Horizontal directional drilling (HDD) is a relatively new drilling technology that has been successfully adapted to site remediation. In addition to the benefits that HDD provides for the logistics of site cleanup, it also delivers sustainability advantages, compared to alternative construction methods.