Search results for "remediation."

Change of arsenite adsorption mechanism during aging of 2-line ferrihydrite in the absence of oxygen

2018

Abstract Arsenite was effectively immobilized by 2-line ferrihydrite at different pH values (4.0, 5.5 and 7.4) and adsorbent dosages (0.4, 1, and 2 g/L) in the absence of oxygen, showing an initial surface diffusion-controlled period (Stage I, 2 h). Dissolved δ 56 Fe increased during Stage I and decreased during Stage II, resulting from aging of ferrihydrite and equilibrium isotopic exchange, respectively. The ferrihydrite aging was hampered by both high As concentrations and high pH values close to the pH zpc , due to inhibition of mineral dissolution as a prerequisite for mineral transformation. During Stage I, As was adsorbed by both bidentate binuclear corner-sharing ( 2 C ) and monoden…

Development of a new peat-based oil sorbent using peat pyrolysis

2013

The growing use and transport of crude oil and oil products has led to increasing numbers of oil spillages of various scales. Oil sorbents have been extensively used for remediation of the consequences of such accidents. The aim of this study is to investigate the possible use of peat and its thermal treatment products for oil sorption. Peat as an oil sorbent has poor buoyancy characteristics, relatively low oil sorption capacity and low hydrophobicity. However, thermal treatment (low-temperature pyrolysis and synthesis of peat-based activated coal) helps to significantly improve its sorptive characteristics. Peat is a potential material for oil sorption because it has such advantages as lo…

Synthesis, Characterization, and Study, of New Nanostructured Materials

Simultaneous Removal and Recovery of Metal Ions and Dyes from Wastewater through Montmorillonite Clay Mineral

2019

The main objective of this work was to evaluate the potential of Montmorillonite nanoclay (Mt), readily and inexpensively available, for the simultaneous adsorption (and removal) of two classes of pollutants: metal ions and dyes. The attention was focused on two &ldquo

Analysis of the Effectiveness of Cognitive Remediation and Emotional Skills Training in a Group format. Preliminary results in patients with eating d…

2019

Eating disorders (ED) are associated with cognitive and emotional impairments. Cognitive and Emotional Remediation Skill Training (CREST) was developed as an intervention program targeting patients' thinking styles and their skills in recognizing and managing emotions. AIM: to analyze the effects of the CREST intervention in a group format in females with ED. METHOD: eight females underwent a CREST program (eight 90-minute sessions) targeting cognitive (central coherence, set shifting, problem solving) and emotional (recognizing emotions, managing emotions) difficulties. It was assessed cognitive flexibility (Wisconsin Card Sorting Test), decision-making (Iowa Gambling Task), central cohere…

Decomposer animals and bioremediation of soils

1998

Abstract Although microorganisms are degrading the contaminants in bioremediation processes, soil animals can also have important — while usually an indirect — role in these processes. Soil animals are useful indicators of soil contamination, both before and after the bioremediation. Many toxicity and bioavailability assessment methods utilizing soil animals have been developed for hazard and risk-assessment procedures. Not only the survival of the animals, but also more sensitive parameters like growth, reproduction and community structure have often been taken into account in the assessment. The use of bioassays together with chemical analyses gives the most reliable results for risk anal…

Uptake prediction of nine heavy metals by Eichhornia crassipes grown in irrigation canals: A biomonitoring approach

2021

The principal objective of this study is to generate mathematical regression equations that facilitate the estimation of the extent to which Eichhornia crassipes (C. Mart.) Solms, water hyacinth, absorbs heavy metals (HMs) into four plant organs (laminae, petioles, roots, and stolons). This study considers the absorption of nine HMs (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn), and the E. crassipes evaluated in this study were located in three irrigation canals in the North Nile Delta in Egypt, with sampling being conducted in both monospecific and homogenous E. crassipes. Samples of both E. crassipes and water were collected on a monthly basis during one growing season. Analysis of the water s…

Photocatalytic ozonation under visible light for the remediation of water effluents and its integration with an electro-membrane bioreactor

2018

Abstract Photocatalysis and photocatalytic ozonation under visible light have been applied for the purification of a complex aqueous matrix such as the grey water of Masdar City (UAE), by using N-doped brookite-rutile catalysts. Preliminary runs on 4-nitrophenol (4-NP) solutions allowed to test the reaction system in the presence of a model pollutant and to afford the relevant kinetic parameters of the process. Subsequently, the remediation of grey water effluent has been evaluated in terms of the reduction of total organic carbon (TOC) and bacterial counts. The concentration of the most abundant inorganic ionic species in the effluent has been also monitored during reaction. Photocatalytic…

Electrochemical remediation of kaolin-soil contaminated by phenol: effect of several operative parameters

Electrochemical remediation technology is considered an appealing strategy for the remediation of fine- grained soils, characterized by a low hydraulic conductivity and large specific surface area, contaminated with inorganic, organic, and mixed pollutants. In both Electrokinetic (EK) and Electrochemical Geo-Oxidation (ECGO) technologies, an electric field is imposed on the contaminated soil to remove the pollutants by the combined mechanisms of electroosmosis, electromigration, and/or electrophoresis. Moreover, ECGO uses low voltage and both direct and alternating amperage (DC/AC) applied in a proprietary series to induce reduction-oxidation reactions on soil surfaces at the micro-scale. A…

Heavy metal remediation technologies in Latvia: possible applications and preliminary case study results / Technologie remediacji obszarów zanieczysz…

2012

Abstract Environmental contamination with heavy metals as a result of anthropogenic activities is not a recent phenomenon. Contaminated sites with heavy metals can be found in functioning as well as abandoned industrial (brownfield) territories, landfills, residential areas with historical contamination, road sides and rarely in polluted sites by natural activities. Pollution data on its amount and concentrations is known from historical studies and monitoring nowadays, but it should be periodically updated for the use of territorial planning or in case of a change of the land use. A special attention should be paid to heavy metal contamination, because in many cases this contamination is m…