Search results for " Remediation"
showing 10 items of 154 documents
Contaminant Mobilization from Polluted Soils: Behavior and Reuse of Leaching Solutions
2020
Soil and water contamination by toxic elements or molecules cause risks of chemical pollutions. These pollutions can heavily affect resources and activities of humans and ecosystems. By nature, the remediation of environmental pollutions is a constraint, because its application is hampered by high costs. Soil and groundwater remediation implements a variety of strategies, technologies, and practices to face the diversity and the complexity of every cases. Contaminant recovery is among the three main strategies implemented for the remediation of contaminated soils, and contaminant separation or mobilization by water is widely used for this purpose. As water solubility is the driving force of…
Assessment of toxicity hazards of dredged lake sediment contaminated by creosote.
2000
In order to predict the potential toxicity hazards of sediment remediation by dredging, an experimental laboratory simulation was made by investigating seven ratios of creosote-contaminated sediment (Lake Jamsanvesi, central Finland) and artificial lake water mixtures. Sediment was suspended in water at the ratios of 1:1, 1:2, 1:4, 1:8, 1:16, 1:32, 1:64, 1:128 v/v. The elutriates were analysed for the acute toxicity by photoluminescence bacterial and waterflea (Daphnia magna Straus) tests. The concentrations of polycyclic aromatic hydrocarbons (PAHs) are determined by gas chromatography (GC/FID). The elutriate of ratio 1:2 was most toxic to bacteria (EC50 = 4.5%), whereas the ratio 1:4 was …
The combined effect of phytostabilization and different amendments on remediation of soils from post-military areas
2019
Army bases and battle fields are areas of high pollution due to the chemicals released there. Soils in these areas suffer from these uses of the land, and ecosystem services are affected. Although, in the 20th century, the production of bombs and the locations of battle fields and army bases were widespread, there is little research on the impact of war on nature. Moreover, there is a need to rehabilitate the disturbed soils. The contents and ecological risks of Cu, Ni, Cd, Pb, Zn, and Cr in the topsoil from a post-military area (north-eastern Poland) were investigated. In addition, a vegetation experiment was performed with the technique of aided phytostabilization on soils from the study …
Microplastics in the global aquatic environment: Analysis, effects, remediation and policy solutions
2019
This opinion paper reports on Microplastics (MPs) pollution in the aquatic environment. MPs are a global problem being detected everywhere: marine environment, wastewaters, surface waters, soils, sediments, food and air. MPs can also absorb organic contaminants, and can be ingested by organisms and introduced into the food web. MPs can be a vector as well of pathogens whereas airborne fibrous MPs may enter our respiratory system with risk to the environment and humans. Main issues and gaps related to MPs on-going and future research are highlighted: chemical analysis, fate in wastewater and drinking water treatment plants, environmental and human health effects as well as remediation strate…
The contamination legacy of a decommissioned iron smelter in the Italian Alps
2018
The economically important activity of metal processing can tend to contribute to the degradation of the environment. Smelting is an important source of contaminants, dispersing large quantities of potentially toxic elements (PTE) and coproducts into the environment. Soils in the vicinity of smelters frequently contain high concentrations of PTE. In terms of the quantities processed, the major PTE are iron (Fe), aluminium (Al), copper (Cu), lead (Pb), manganese (Mn), and zinc (Zn); of these Cu, Pb and Zn are, potentially, highly hazardous elements. The general problem addressed by this study is to determine if the PTE concentration in the soils of an area downwind from a decommissioned iron…
Modelling biological and chemically induced precipitation of calcium phosphate in enhanced biological phosphorus removal systems
2011
The biologically induced precipitation processes can be important in wastewater treatment, in particular treating raw wastewater with high calcium concentration combined with Enhanced Biological Phosphorus Removal. Currently, there is little information and experience in modelling jointly biological and chemical processes. This paper presents a calcium phosphate precipitation model and its inclusion in the Activated Sludge Model No 2d (ASM2d). The proposed precipitation model considers that aqueous phase reactions quickly achieve the chemical equilibrium and that aqueous-solid change is kinetically governed. The model was calibrated using data from four experiments in a Sequencing Batch Rea…
The cognitive therapy of evaluation: Therapeutic techniques-[2]
1991
Abstract The main aim of this paper is to introduce the techniques used in cognitive therapy of evaluation. The Cognitive therapy of evaluation is being developed from the theoretical background of general semantics theory and it is a therapy based on language as an instrument of cognitive processes, and on the role it plays, through word-facts identification, in the development and treatment of emotional problems. The main techniques developed (abstraction orders and the extensional devices) and other therapeutic issues are introduced and explained.
Electroreduction of aliphatic chlorides at silver cathodes in water
2010
The effect of water on the reduction of aliphatic chlorides at silver cathodes was investigated by cyclovoltammetric experiments in acetonitrile, water and their mixture and focused electrolyses in water solutions. The addition of water to acetonitrile gives rise to the formation of new peaks and/or the displacement of pre-existent peaks at dramatically less negative potentials. In a water medium, silver shows a very large electrocatalytic effect towards the reduction of chlorinated aliphatic compounds belonging to the classes of chloromethanes, chloroethanes and chloroethenes, dramatically higher than that observed in aprotic solvents such as dimethylformamide (DMF) or acetonitrile (ACN). …
Renewable energies driven electrochemical wastewater/soil decontamination technologies: A critical review of fundamental concepts and applications
2020
Abstract Electrochemical wastewater and soil treatments are exciting set of technologies that has been well-studied over the recent years as one of the most-effective remediation techniques for the removal of hazardous pollutants from liquids effluents and soil. The main requirement of these technologies is electricity and their sustainability can be largely improved if they are powered by renewable energy sources. Likewise, this green energy powering can help to apply these technologies in remote areas, such as rural communities in developing countries, where no electricity grid is available. This review presents a comprehensive discussion on fundamental concepts and applications of renewa…
Development of a process for the treatment of synthetic wastewater without energy inputs using the salinity gradient of wastewaters and a reverse ele…
2019
Abstract Electrochemical processes are considered very effective methods for the treatment of wastewater contaminated by organics resistant to conventional biological processes and various inorganic pollutants. Large sites that treat wastewaters usually deal with a large number of waters often characterized by different salinity contents, that could be potentially used to provide the energy necessary for the electrochemical remediation. Hence, in this work a reverse electrodialysis (RED) process for the treatment of synthetic wastewaters contaminated by organics, without energy inputs, using the salinity gradient of different wastewaters, was studied, for the first time. It was found that t…