Carbon dioxide sequestration by mineral carbonation iron complexation using bipyridine chelating ligands.

An innovative mineral carbonation method was developed to synthesize iron(II) carbonate (FeCO) by cation complexation using 2,2'-bipyridine as ligand. First, complexes of iron(II) and different ligands were theoretically analyzed and discounted in terms of their temperature and pH-dependent stabilities, iron-ligand interactions, possible by-products and difficulty of analysis, choosing 2,2'-bipyridine as the most suitable ligand. Then, the Job plot was used to verify the complex formula.

Persulfate activated with calcium peroxide to remediate RAFT soil contaminated with diesel in Arctic northern villages: on-site pilot scale study.

A pilot field study was conducted in a Canadian northern village (NV) to assess the remediation efficiency of sodium persulphate (SPS) alkali activated with calcium peroxide (CP) to degrade diesel from Arctic raft soil. A minimum temperature increase in the subsurface due to overall process reactions was required. The projected context of application was imperative to preserve the integrity of the remaining permafrost.

Physical process to sort construction and demolition waste (C&DW) fines components using process water.

Modern societies are generating considerable volume of Construction and Demolition Wastes (C&DW) annually. Most recycling facilities offers viable sorting and recycling options for the coarser particles of the different materials found in those wastes. However, usual dry mechanical sorting and human sorting are not efficient on C&DW fines particles (C&DF, <10 mm) representing the third of the C&DW produced and being composed of similar materials.

Geochemical behavior and stabilization of spent sulfate-reducing biofilter mixtures for treatment of acid mine drainage.

Sulfate-reducing biofilters operated in semi-passive or passive modes constitute an approach of choice for treatment of acidic mining effluents. The aim of the present study involved examining the behavior of biofilters after use based on two modes of management, namely in unsaturated and saturated media. Two acidophilic biofilters were investigated following their mixing with different alkaline industrial residues (i.

Prediction of physical separation of metals from soils contaminated with municipal solid waste ashes and metallurgical residues.

Environmental legislation is forcing industrialized countries to rehabilitate contaminated lands. Expensive solutions are available to treat soils contaminated by metals (e.g.

Comparison of different interpolation methods and sequential Gaussian simulation to estimate volumes of soil contaminated by As, Cr, Cu, PCP and dioxins/furans.

Understanding the spatial distribution of organic and/or inorganic contaminants is crucial to facilitate decision-making of rehabilitation strategies in order to ensure the most appropriate management of contaminated sites in terms of contaminant removals efficiencies and operating costs. For these reasons, various interpolation methods [Thiessen Polygon (TP) method, inverse of distance (IDW) method, ordinary kriging (OK), as well as sequential Gaussian simulations (SGS)] were used to better understand the spatial distribution of As, Cr, Cu, pentachlorophenol (PCP) and dioxins and furans (PCDD/F) found onto a specific industrial site. These methods do not only vary in complexity and efficiency but also lead to different results when using values coming from the same characterization campaign.

Semi-passive in-situ pilot scale bioreactor successfully removed sulfate and metals from mine impacted water under subarctic climatic conditions.

Mine drainage contaminated with metals is a major environmental threat since it is a source of water pollution with devastating effects on aquatic ecosystems. Conventional active treatment technologies are prohibitively expensive and so there is increasing demand to develop reliable, cost-effective and sustainable passive or semi-passive treatment. These are promising alternatives since they leverage the metabolism of microorganisms native to the disturbed site at in situ or close to in situ conditions.

Study of factors involved in the gravimetric separation process to treat soil contaminated by municipal solid waste.

The current research investigated the effectiveness of a gravimetric process (shaking table) to treat soil contaminated by municipal solid waste. A detailed characterization of the inorganic pollutants was performed, followed by concentrating the metals within smaller volumes using the shaking table technology. The densimetric examination of the 1-2 mm and 0.

Effect of pCO on direct flue gas mineral carbonation at pilot scale.

Concerns about global warming phenomena induced the development of research about the control of anthropogenic greenhouse gases emissions. The current work studies on the scaling up of aqueous mineral carbonation route to reduce the CO emissions at the chimney of industrial emitters. The reactivity of serpentinite in a stirred tank reactor was studied for several partial pressures of CO (pCO) (0.

Treatment technologies used for the removal of As, Cr, Cu, PCP and/or PCDD/F from contaminated soil: A review.

The contamination of soils by metals such as arsenic, chromium, copper and organic compounds such as pentachlorophenol (PCP) and dioxins and furans (PCDD/F) is a major problem in industrialized countries. Excavation followed by disposal in an appropriate landfilling is usually used site to manage these contaminated soils. Many researches have been conducted to develop physical, biological, thermal and chemical methods to allow the rehabilitation of contaminated sites.

Study of the factors influencing the metals solubilisation from a mixture of waste batteries by response surface methodology.

This paper presents an innovative process for the recovery of valuable metals from a mixture of spent batteries. Different types of batteries, including alkaline, zinc-carbon (Zn-C), nickel cadmium (Ni-Cd), nickel metal hydride (Ni-MH), lithium ion (Li-ion) and lithium metallic (Li-M) batteries, were mixed according to the proportion of the Canadian sales of batteries. A Box-Behnken design was applied to find the optimum leaching conditions allowing a maximum of valuable metal removals from a mixture of spent batteries in the presence of an inorganic acid and a reducing agent.

Optimizing removal of arsenic, chromium, copper, pentachlorophenol and polychlorodibenzo-dioxins/furans from the 1-4 mm fraction of polluted soil using an attrition process.

The objective of this study was to evaluate, at a pilot scale, the performance of an attrition process for removing As, Cr, Cu, pentachlorophenol (PCP) and polychlorodibenzodioxins and furans (PCDDF) from a 1-4 mm soil fraction. A Box-Behnken experimental design was utilized to evaluate the influence of several parameters (temperature, surfactant concentration and pulp density) and to optimize the main operating parameters of this attrition process. According to the results, the concentration of surfactant (cocamidopropylbetaine-BW) was the main parameter influencing both PCP and PCDDF removal from the 1-4 mm soil fraction by attrition.

Recovery of metals from a mixture of various spent batteries by a hydrometallurgical process.

Spent batteries contain hazardous materials, including numerous metals (cadmium, lead, nickel, zinc, etc.) that are present at high concentrations. Therefore, proper treatment of these wastes is necessary to prevent their harmful effects on human health and the environment.

CO2 sequestration by mineral carbonation of steel slags under ambient temperature: parameters influence, and optimization.

This work focuses on the influence of different parameters on the efficiency of steel slag carbonation in slurry phase under ambient temperature. In the first part, a response surface methodology was used to identify the effect and the interactions of the gas pressure, liquid/solid (L/S) ratio, gas/liquid ratio (G/L), and reaction time on the CO2 removed/sample and to optimize the parameters. In the second part, the parameters' effect on the dissolution of CO2 and its conversion into carbonates were studied more in detail.

Degradation of polycyclic aromatic hydrocarbons in different synthetic solutions by Fenton's oxidation.

The Fenton oxidation using phenanthrene (Phe), fluoranthene (Fle) and benzo[a]pyrene (BaP) as representative polycyclic aromatic hydrocarbon (PAH) contaminants was examined. The effect of the HO concentration, the temperature and the competition between the PAHs in different solutions (methanol, surfactant and quartz) was investigated. The Fenton oxidation process was performed at pH = 2.

Remediation of inorganic contaminants and polycyclic aromatic hydrocarbons from soils polluted by municipal solid waste incineration residues.

Three soils polluted by municipal solid waste (MSW) incineration residues and containing various concentrations of Cu, Pb, Sb, Sn and Zn were treated using magnetism, gravity separation (jig and shaking table) and flotation/leaching. The process removed between 18% and 39% of the contaminants present in soil 1, between 31% and 53% of the contaminants present in soil 2 and between 42% and 56% of the contaminants present in soil 3. Polycyclic aromatic hydrocarbons were present only in soil 3, and the process removed 64% of its PAHs total content.

CO2 sequestration using waste concrete and anorthosite tailings by direct mineral carbonation in gas-solid-liquid and gas-solid routes.

Mineral carbonation (MC) represents a promising alternative for sequestering CO2. In this work, the CO2 sequestration capacity of the available calcium-bearing materials waste concrete and anorthosite tailings is assessed in gas-solid-liquid and gas-solid routes using 18.2% flue CO2 gas.

Direct gas-solid carbonation of serpentinite residues in the absence and presence of water vapor: a feasibility study for carbon dioxide sequestration.

Mineral carbonation of serpentinite mining residue offers an environmentally secure and permanent storage of carbon dioxide. The strategy of using readily available mining residue for the direct treatment of flue gas could improve the energy demand and economics of CO2 sequestration by avoiding the mineral extraction and separate CO2 capture steps. The present is a laboratory scale study to assess the possibility of CO2 fixation in serpentinite mining residues via direct gas-solid reaction.

Reaction mechanism for the aqueous-phase mineral carbonation of heat-activated serpentine at low temperatures and pressures in flue gas conditions.

Mineral carbonation is known as one of the safest ways to sequester CO2. Nevertheless, the slow kinetics and low carbonation rates constitute a major barrier for any possible industrial application. To date, no studies have focused on reacting serpentinite with a relatively low partial pressure of CO2 (pCO2) close to flue gas conditions.

Decontamination of metals, pentachlorophenol, and polychlorined dibenzo-p-dioxins and dibenzofurans polluted soil in alkaline conditions using an amphoteric biosurfactant.

In this paper, flotation in acidic conditions and alkaline leaching soil washing processes were compared to decontaminate four soils with variable contamination with metals, pentachlorophenol (PCP), and polychlorodibenzo dioxins and furans (PCDD/F). The measured concentrations of the four soils prior treatment were between 50 and 250 mg/kg for As, 35 and 220mg/kg for Cr, 80 and 350mg/kg for Cu, and 2.5 and 30mg/kg for PCP.

Decontamination of metals and polycyclic aromatic hydrocarbons from slag-polluted soil.

Metallurgy is an industrial activity that is one of the largest contributors to soil contamination by metals. This contamination is often associated with organic compound contamination; however, little research has been aimed at the development of simultaneous processes for decontamination as opposed to treatments to heavy metals or organic compounds alone. This paper presents an efficient process to decontaminate the soils polluted with smelting by-products rich in Cu, Zn and polycyclic aromatic hydrocarbons (PAHs).

Counter-current acid leaching process for the removal of Cu, Pb, Sb and Zn from shooting range soil.

This research explores the performance of a counter-current leaching process (CCLP) for Cu, Pb, Sb and Zn extraction in a polluted shooting range soil. The initial metal concentrations in the soil were 1790 mg Cu/kg, 48,300 mg Pb/kg, 840 mg Sb/kg and 368 mg Zn/kg. The leaching process consisted of five one-hour acid leaching steps, which used 1 M H2SO4 + 4 M NaCl (20 degrees C, soil suspension = 100 g/L) followed by two water rinsing steps.

Demonstration of the efficiency and robustness of an acid leaching process to remove metals from various CCA-treated wood samples.

In recent years, an efficient and economically attractive leaching process has been developed to remove metals from copper-based treated wood wastes. This study explored the applicability of this leaching process using chromated copper arsenate (CCA) treated wood samples with different initial metal loading and elapsed time between wood preservation treatment and remediation. The sulfuric acid leaching process resulted in the solubilization of more than 87% of the As, 70% of the Cr, and 76% of the Cu from CCA-chips and in the solubilization of more than 96% of the As, 78% of the Cr and 91% of the Cu from CCA-sawdust.

Pilot-scale investigation of the robustness and efficiency of a copper-based treated wood wastes recycling process.

The disposal of metal-bearing treated wood wastes is becoming an environmental challenge. An efficient recycling process based on sulfuric acid leaching has been developed to remove metals from copper-based treated wood chips (0 View Article and Find Full Text PDF