Are contaminated soil and groundwater remediation with nanoscale zero-valent iron sustainable? An analysis of case studies.

Nanoscale zero valent iron (nZVI) is globally the main nanomaterial used in contaminated site remediation. This study aims to evaluate the sustainability of using nZVI in the nanoremediation of contaminated sites and to determine the factors that affect the sustainability of the use of nZVI in remediation. Five case studies of nZVI use on a pilot scale were selected.

Design of a central tool for sustainability evaluation and weighting to decision-making support of contaminated soils remediation.

Sustainable remediation remains unstandardized and ambiguously regulated, thereby limiting its adoption in the management of contaminated areas. Although a considerable number of tools are available for this purpose, numerous shortcomings continue to be detected, especially with regard to the integration of a complete assessment of impact and sustainability into a single framework. In view of these problems, the objective in this study was to develop and validate an integrated tool for assessing the sustainability of remediation techniques for contaminated soils.

Optimization of biocementation responses by artificial neural network and random forest in comparison to response surface methodology.

In this article, the optimization of the specific urease activity (SUA) and the calcium carbonate (CaCO) using microbially induced calcite precipitation (MICP) was compared to optimization using three algorithms based on machine learning: random forest regressor, artificial neural networks (ANNs), and multivariate linear regression. This study applied the techniques in two existing response surface method (RSM) experiments involving MICP technique. Random forest-based models and artificial neural network-based models were submitted through the optimization of hyperparameters via cross-validation technique and grid search, to select the best-optimized model.

Toxicity of nZVI in the growth of bacteria present in contaminated soil.

The use of nano zero-valent iron (nZVI) for the remediation of degraded areas is a consolidated practice. However, the long-term reactions that occur in the environment remain unknown. This study aimed to evaluate the potential toxic effects on the growth of colony-forming units (CFUs) of Bacillus cereus and Pseudomona aeruginosa present in soil contaminated with hexavalent chromium (Cr) and pentachlorophenol (PCP) nanoremediated with nZVI.

Social life cycle assessment of the nanoscale zero-valent iron synthesis process for application in contaminated site remediation.

Nanoscale zero-valent iron (nZVI) is the main nanomaterial used in environmental remediation processes. However, as with any remediation technique, the production and the use of nanomaterials can also cause environmental, economic, and social impacts. Thus, the present study investigated the social life cycle analysis (S-LCA) of nZVI production methods applied in environmental remediation.

Global sales and operations planning: A multinational manufacturing company perspective.

The purpose of this paper is to analyse the global Sales and Operations Planning (S&OP) process and investigate the steps to support consolidated business planning in worldwide operations and large-scale supply chains. The paper conducts a case study at a multinational manufacturing company applying an abductive approach. It combines the deductive logic from theory and the inductive logic from field observation in an attempt to elaborate further on theory on global S&OP.

Improving the Bioremediation and in situ Production of Biocompounds of a Biodiesel-Contaminated Soil.

We aimed to produce simultaneously biosurfactants and lipases in solid state fermentation (SSF) using Aspergillus niger, followed by the use of the fermented media on the bioremediation of oily contaminated soil, in order to valuate agro industrial residuals and reduce the contamination. The biocompounds were produced using wheat bran and corncob (80:20), 5% of soybean oil and 0.5% of sugar cane molasses in SSF for 4 d, producing 4.

Bacterial biosurfactant increases ex situ biodiesel bioremediation in clayey soil.

The contamination of soils by oily compounds has several environmental impacts, which can be reversed through bioremediation, using biosurfactants as auxiliaries in the biodegradation process. In this study, we aimed to perform ex situ bioremediation of biodiesel-contaminated soil using biosurfactants produced by Bacillus methylotrophicus. A crude biosurfactant was produced in a whey-based culture medium supplemented with nutrients and was later added to biodiesel-contaminated clayey soil.

Nano scale zero valent iron production methods applied to contaminated sites remediation: An overview of production and environmental aspects.

The nano scale zero valent iron (nZVI) is the most used material in the remediation process. The inclusion of sustainability in the remediation process has also been gaining prominence. Sustainable remediation seeks to consider the environmental, economic and social impacts of remediation.

Life cycle sustainability assessment of the nanoscale zero-valent iron synthesis process for application in contaminated site remediation.

Nanoscale zero-valent iron (nZVI) is the main nanomaterial used in environmental remediation processes. The present study aims to evaluate the life cycle sustainability of nZVI production methods applied in environmental remediation. Three production methods of nZVI were selected for analysis: milling, liquid reduction with sodium borohydride, and chemical reduction with hydrogen gas (in two approaches: considering the goethite and hematite synthesis and after using in nZVI production and, using goethite and hematite particles already synthesized for nZVI production).

What factors predict length of stay in the intensive care unit? Systematic review and meta-analysis.

Purpose: Studies have shown that a small percentage of ICU patients have prolonged length of stay (LoS) and account for a large proportion of resource use. Therefore, the identification of prolonged stay patients can improve unit efficiency. In this study, we performed a systematic review and meta-analysis to understand the risk factors of ICU LoS.

Effects of homemade biosurfactant from Bacillus methylotrophicus on bioremediation efficiency of a clay soil contaminated with diesel oil.

Despite constant progress in the understanding of the mechanisms related to the effects of biosurfactants in the bioremediation processes of oily residues, the possibility of antagonist effects on microbial growth and the production in situ of these compounds must be elucidated. The aims of this work were a) to evaluate the effects of the addition of a homemade biosurfactant of Bacillus methylotrophicus on the microbial count in soil in order to determine the possibility of inhibitory effects, and b) to accomplish biostimulation using media prepared with whey and bioaugmentation with B. methylotrophicus, analyzing the effects on the bioremediation of diesel oil and evidencing the in situ production of biosurfactants through effects on surface tension.

Use of Nanoscale Zero-Valent Iron for Remediation of Clayey Soil Contaminated with Hexavalent Chromium: Batch and Column Tests.

This study investigated the reduction of hexavalent chromium (Cr(VI)) in a clayey residual soil using nanoscale zero-valent iron (nZVI). Five different ratios between nZVI and Cr(VI) were tested in batch tests (1000/11; 1000/23; 1000/35; 1000/70, and 1000/140 mg/mg) with the soil. With the selected proportion resulting best efficiency, the column tests were conducted, with molded specimens of 5 cm in diameter and 5 cm in height, with different nZVI injection pressures (10, 30, and 100 kPa).

Influence of nanoscale zero-valent iron on hydraulic conductivity of a residual clayey soil and modeling of the filtration parameter.

Contaminated clay soils pose problems to public health and the environment in several parts of the world. Very little is known about the transport of decontaminating agents used in remediation process under natural, undisturbed conditions. Nanomaterials, especially those made of nanoscale zero-valent iron (nZVI), have been most frequently used for remediation of contaminated soils because of their higher reactivity, lower toxicity, and lower cost than other metallic nanoparticles.

Proposal for an optimized method for sustainable remediation evaluation and application: implementation of a multi-criteria process.

As sustainable remediation methods do not yet have a consolidated approach, a detailed assessment of the level of satisfaction for sustainability prospects is necessary. So, this study aims to evaluate the sustainability level of sustainable remediation methods according to the visions of decision makers in this field, in order to propose an optimized method that best represents its approach. We considered eight methods applied to sustainable remediation and nine decision criteria for evaluation.

Sustainable remediation through the risk management perspective and stakeholder involvement: A systematic and bibliometric view of the literature.

Sustainable remediation is a new way of thinking and acting in the management of contaminated sites. This research aims to identify and structure the state-of-the-art of sustainable remediation from the risk management and stakeholder involvement perspective. A systematic and bibliometric study of scientific production was performed on scientific papers indexed in the Scopus and Web of Science databases with the objectives: 1) to select a bibliographic portfolio that is aligned with the perception of the researchers in regard to theme, 2) to perform a bibliometric analysis of the selected bibliographic portfolio, and 3) to conduct a thematic synthesis and identify the integration of sustainable remediation from the risk management and stakeholder involvement perspective.

Bibliometric study of the toxicology of nanoescale zero valent iron used in soil remediation.

The application of nanoscale zero-valent iron is one of the most widely used remediation technologies; however, the potential environmental risks of this technology are largely unknown. In order to broaden the knowledge on this subject, the present work consists of a bibliometric study of all of publications related to the toxicity of zero-valent iron nanoparticles used in soil remediation available from the Scopus (Elsevier) and Web of Science (Thompson Reuters) databases. This study presents a temporal distribution of the publications, the most cited articles, the authors who have made the greatest contribution to the theme, and the institutions, countries, and scientific journals that have published the most on this subject.

Quantitative Assessment of Life Cycle Sustainability (QUALICS): Framework and its application to assess electrokinetic remediation.

In recent years, the broader environmental impacts of remediation that arise from different remediation activities has drawn attention of practitioners, remediation design professionals and academicians to evaluate the net environmental benefit of environmental remediation projects. The main objective of this paper is to describe the Quantitative Assessment of Life Cycle Sustainability (QUALICS) framework, a new tool developed to strengthen decision-making in the selection of sustainable remedial technologies for the clean-up of contaminated sites. The proposed framework is a combination of two multi-criteria evaluation methods namely, the Integrated Value Model for Sustainable Assessment (MIVES) and Analytic Hierarchy Process (AHP).

Application of life cycle assessment as a tool for evaluating the sustainability of contaminated sites remediation: A systematic and bibliographic analysis.

As the discussion surrounding sustainable remediation has advanced, numerous tools have been developed to evaluate the sustainability of remediation technologies, including life cycle assessment (LCA). In the present study, a systematic and bibliometric analysis of scientific articles indexed in the databases of Scopus and the Web of Science in the field of LCA was performed, particularly studies relating to the remediation of contaminated sites from a sustainability perspective. We selected a bibliographic portfolio (BP) of papers related to sustainable remediation using LCA.

Biosurfactants during in situ bioremediation: factors that influence the production and challenges in evalution.

Research on the influence of biosurfactants on the efficiency of in situ bioremediation of contaminated soil is continuously growing. Despite the constant progress in understanding the mechanisms involved in the effects of biosurfactants, there are still many factors that are not sufficiently elucidated. There is a lack of research on autochthonous or exogenous microbial metabolism when biostimulation or bioaugmentation is carried out to produce biosurfactants at contaminated sites.

Biostimulation and rainfall infiltration: influence on retention of biodiesel in residual clayey soil.

Unlabelled: This study investigates the retention of biodiesel in residual clayey soil during biostimulation by nutrients (nitrogen, phosphorus, and potassium) under conditions of rainfall infiltration. Several column tests were conducted in a laboratory under different void ratios (1.14, 1.

Sustainable infrastructure: A review and a research agenda.

This paper proposes a taxonomy of themes and a research agenda on sustainable infrastructure, with a focus on sustainable buildings (SB) and green infrastructure (GI). The citation databases of Web of Science formed the basis for a novel strategic thematic analysis of co-citation and co-occurrence of keywords with a longitudinal identification of themes during the last two decades (from 1995 to 2015) of an emerging and ever growing research area. SI is a multidisciplinary endeavour, including a diversified array of disciplines as general engineering, environmental ecology, construction, architecture, urban planning, and geography.

Potential of Live Spirulina platensis on Biosorption of Hexavalent Chromium and Its Conversion to Trivalent Chromium.

Microalga biomass has been described worldwide according their capacity to realize biosorption of toxic metals. Chromium is one of the most toxic metals that could contaminate superficial and underground water. Considering the importance of Spirulina biomass in production of supplements for humans and for animal feed we assessed the biosorption of hexavalent chromium by living Spirulina platensis and its capacity to convert hexavalent chromium to trivalent chromium, less toxic, through its metabolism during growth.