Chemical Fractionation Of Copper Research Articles

Changes in chemical fractionation of copper and zinc in soil as a function of incubation moisture content and organic matter amendments

Copper and zinc are essential micronutrients that are potentially toxic when present in excess in soils. Their bioavailability depends on their speciation in soil, but this may vary with environmental conditions. Aeration and hence redox conditions, and organic matter amendments are among the factors likely to cause variation on metal fractionation. We have monitored the chemical fractionation of both native and added copper and zinc in a clay loam top soil during a 5-month laboratory incubation. The effects of aeration (moist soil or flooded) and addition of two organic matter amendments, alfalfa straw or leaf compost, were studied. Metal spike was more labile than legacy metal, and was slowly redistributed over the incubation period. Organic matter caused short-lived flushes of metals, attributed to metal chelation with soluble organic matter. This effect was greater for straw than for more stable compost. There was no evidence that added organic matter increased the capacity of soil organic matter to immobilise metal. Flooding solubilized soil metal (hydr)oxides, releasing legacy Cu and Zn, but with less effect on the capacity to immobilise metal spike. Effects of flooding and organic matter addition were not additive. Both metals appear to be precipitated as sulphides under reducing conditions, and accounted for in the acid soluble phase. Monitoring the dynamics of metal distribution gives a more comprehensive understanding of underlying processes than would a single measurement, and is closer to in campo conditions than slurry microcosms.

Remediation of Cd and Cu Contaminated Agricultural Soils near Oilfields by Biochar Combined with Sodium Humate-Wood Vinegar

Soil contaminations by heavy metals near oilfields have been widely reported and are causing great concern. Thus, it is highly desirable to develop cost-effective materials and methods to avoid heavy metal residues contaminating soil and food. An effective, environmentally friendly, and inexpensive remediation material for heavy metal-polluted soil was designed and prepared using biochar (BC) combined with humic acid (HA) resulting from sodium humate (NaHA) simply reacting with wood vinegar (BHW). After adding BHW, the chemical fractions of copper and cadmium in the soil undergo larger changes. Meanwhile, the availability of heavy metals decreases. The maximum adsorption capacity of copper and cadmium in the soil using the BHW is larger than that only using biochar. The adsorption kinetics ensures that the adsorption process of Cd2+ and Cu2+ ions on BHW is chemical adsorption, which is best fitted using the pseudo-second-order rate equation. The thermodynamics guarantees that the metal ions adsorb on the heterogeneous surface of BHW in multilayer, which is credited to the enhancement of oxygen-containing groups in the biochar combined with the humic acid. The remediation material BHW holds promise for the immobilization of heavy metal in the soils and could be recommended based on its economic feasibility, high efficacy, and environmental safety.

Chemical Fractionation of Copper and Zinc After Addition of Conocarpous Waste Biochar to A Drill Cutting

Background: Drill Cutting (DC) are large amount of waste generated in gas and oil exploration and production activities that contains toxic substances, especially heavy metals. This study aimed to use Conocarpus Waste (CW) biochar to investigate its effects on changes in chemical forms and stabilization and distribution of Cu and Zn in DC samples of Ahvaz oil field at different incubation times. Methods: In order to study the effects of CW biochar at different rates (0, 2, 5, and 10% w/w) and four incubation times (1, 2, 4, and 8 weeks) for adsorption and chemical fractionation of Copper (Cu) and Zinc (Zn) in DC of Ahvaz oil field in southwestern Iran. An experiment was conducted as a factorial in a completely randomized designing in three replication. Sequential extraction procedure of Tessier was applied for the determination of heavy metals fraction. Results: Application of biochar significantly (p <0.05) increased the pH, soil organic carbon (SOC), electrical conductivity (EC), and cation exchange capacity (CEC) especially at the 10% application rate. After the addition of CW biochar, the exchangeable (EX) and carbonate (CAR) fractions of Cu and Zn, respectively decreased (P≤0.05) significantly while organic matter (OM) bound, oxides (OX) bound, and residual (RES) fraction were increased. Conclusion: The CW biochar can be a low-cost and effective amendment in immobilizing the Cu and Zn, and also effectively to reducing their mobility in DC.

Chemical fractionation of copper and zinc after addition of carrot pulp biochar and thiourea–modified biochar to a contaminated soil

ABSTRACT In this study, there is presented a thorough investigation of the effect of biochar produced via pyrolysis of carrot pulp with pre and post-modification by thiourea (CH4N2S) at three rates (0, 4%, and 8%) on fractionation of Cu and Zn in acidic soil. The sequential extraction procedure of BCR was utilized for the determination of heavy metals fractionation. According to the FTIR analysis, the thiourea-modified biochar (TMB) had more surface functional groups in comparison with the carrot pulp biochar (CB). The 8% TMB application, was more effective in increasing the CEC, pH, EC, and SOC of the soil than the 8% CB treatment. The BCR test revealed that after the addition of CB and TMB, the acid extractable Cu and Zn decreased considerably. Thiourea-modified biochar was more effective than pristine biochar in decreasing the acid extractable metals fraction. The addition of TMB induced the conversion of the acid extractable fraction of Cu to residual and organic matter bound fractions, and the acid extractable fraction of Zn to residual, organic matter bound and oxides bound fractions. This work suggests that thiourea-modified biochar can be a low-cost and effective amendment for immobilizing Cu and Zn in contaminated acidic soils.

New process for copper migration by bioelectricity generation in soil microbial fuel cells.

The soil microbial fuel cell (MFC) is a promising biotechnology for the bioelectricity recovery as well as the remediation soil. Moreover, there were no studies on the heavy metal pollution in a soil MFC yet. A soil MFC was constructed to remediate the contaminated soil, and the electric field was generated from the oxidation of the acetate at the anode. We demonstrated the copper migration, the power generation, and the pH variation in the soil and the electrodes. The maximal voltage and the power density of 539mV and 65.77mW/m(2) were obtained in the soil MFC. The chemical fractionation of copper (Cu) was analyzed with a modified BCR sequential extraction method. The soluble Cu form and the total Cu contents from the anode to the cathode increased, and the difference between them kept growing over time. The Cu fractions in the soil and the electrodes were converted with the change of the dramatic pH from the anode to the cathode. There was a focusing effect leading to the change of the Cu forms, and the extractable acid form content increased in the three fifths where the acid and the alkali fronts met.

Chemical Fractionation of Copper, Manganese and Zinc in Dumpsite Soil Samples in Kaduna Metropolis, Nigeria

Aims: In this research, sequential chemical extractions were performed to fractionate copper, manganese and zinc in dumpsite soil samples into six geochemical fractions with varying mobility and bioavailability. Study Design: Determination of chemical forms of metals in soils and evaluation of their mobility and bioavailability. Place and Duration of Study: This study was conducted between March, 2011 and June, 2013 in the Department of Chemistry, Ahmadu Bello University, Zaria, Nigeria. Methodology: Collection of soil samples from Kawo (KW), Rafin Guza (RG), Angwan Dosa (AD), Badarawa (BD), Malali (ML), Angwan Shanu (AS), Kurmi Mashi (KM), Tudun Wada (TW), Kakuri (KK) and Trikania (TK) dumpsites; sequentially extraction of samples into six fractions and determination of metal concentrations in extracts. Results: Copper had high mobility factor values in the rainy season at TK (43.76%), TW (13.51%), AS (13.48%) and ML (0.14%); and in the dry season at TK (44.79%), KW (14.65%), AS (14.18%), ML (13.43%) and TW (13.31%). Manganese in the rainy season recorded relatively high mobility values at KK (2.18%), AD (2.07%), and TW (1.67%) and in the dry season at ML (2.57%), BD (2.23%), KK (2.06%) and TW (1.51%) while Zinc had Original Research Article American Chemical Science Journal, 4(2): 138-150, 2014 139 high mobility values in the rainy season at BD (54.14%), AS (26.62%), KM (18.08%), TK (16.11%), ML (5.88%) and KK (3.54%) and in the dry season at RG (145.79%), BD (44.59%), AS (31.08%), KM (21.65%) and TK (18.19%). Copper and zinc were distributed evenly across the non-residual and residual fractions, while manganese was predominantly retained by residual fractions. The mobility and potential bioavailability of the metals in decreasing order is: zinc > Copper > Manganese. Conclusions: The amount of metals bound to each fraction differed significantly according to metal type, dumpsites and seasons. The study indicates the tendency for bioavailability of the metals studied for plant uptake from soil.

Assessment of copper and zinc in soils and fruit with the age of an apple orchard

Chemical fractions of copper and zinc in soils were evaluated and, the transfer coefficient of copper and zinc from soil to apples depending on age of apple orchard were determined. The fractions of copper and zinc in surface soil were in decreasing order: residual > organic-bound > Fe−Mn oxides > carbonates and exchangeable > water-soluble fractions. With increasing age of apple orchard, the residual fraction showed the highest residual fractions of copper and zinc, whereas those of water soluble and exchangeable fractions were relatively low. Tc values of copper and zinc did not show significant difference with the age of apple orchard (p >0.05). As our results show that the concentrations of Zn and Cu in soil increase with age of apple orchard, continuous monitoring and pollution control of hazardous material are needed to prevent the excessive build-up of heavy metals in the food chain.

Copper distribution and hydrolase activities in a contaminated soil amended with dolomitic limestone and compost

Chemical fractionation of copper in bulk soil and its distribution in the particle-size fractions were analyzed in a Cu-contaminated soil (674±122 μg Cu g −1, up to 1900 μg Cu g −1 in the clay fraction) sampled from a wood preservation site left untreated and subsequently treated with dolomitic limestone (DL, 0.2% w/w) and compost (CM, 5% w/w), singly and in combination (DL+CM). Soil enzymatic activities of leucine aminopeptidase, cellulase, N-acetyl-β-glucosaminidase, arylsulfatase, β-glucosidase, acetate esterase, butyric esterase, and acid phosphatase were determined. Chemical speciation showed that Cu was mostly present in the acid-soluble and reducible fractions in both untreated and treated soils, whereas treatments with DL and CM reduced the soluble and exchangeable Cu fractions, due to Cu precipitation and complexation, and increased Cu bound to soil organic matter. Analysis of the particle-size fractions showed that more than 80% of Cu was in the silt and clay fractions and that treatment with CM increased the concentration of Cu in the sand size fractions. Soil treatment with DL and CM, singly or in combination, increased hydrolase activities, mainly in the clay fraction, with the largest positive effects on N-acetyl-β-glucosaminidase, leucine aminopeptidase, and β-glucosidase activities. Overall, results confirm that (1) Cu in contaminated soils is mainly bound to the silt–clay fraction, (2) CM additions change its allocation in the particle-size fractions, and (3) treatments with DL and CM singly and in combination reduce Cu solubility and its inhibitory effects on soil enzyme activities.

Chemical transformation of copper in some sludge-amended soils

In a laboratory incubation study, the periodic changes in different chemical fractions of copper (Cu) in three sludge-amended soil types (acidic sandy clay loam, neutral clay loam and alkaline clay loam) of varying soil reaction were monitored under field capacity and flooding moisture regime over 16 months. The water soluble and exchangeable fraction of Cu was very low (≤1% of total Cu) in all three soil types. At the end of incubation (16 months), the sodium acetate extractable (carbonate sorbed)- and residual-Cu fractions transformed into Fe-Mn oxide fraction, irrespective of moisture regime in all three soil types. However, the extent of transformation varied among soils.

Chemical Fractionation of Copper, Zinc, and Cadmium in Two Chinese Soils as Influenced by Rhizobia

Red soil and Cinnamon soil were collected from Chenzhou of Hunan and Gongyi of Henan, respectively. Soils were treated with Cu(NO3)2, Zn(NO3)2 or Cd(NO3)2, respectively, for two weeks. Rhizobium fredii strain HN01 was inoculated into the two soils polluted with three heavy metals. Sequential extraction method was employed to investigate the forms of copper (Cu), zinc (Zn), and cadmium (Cd) in the examined soils with the absence and presence of rhizobia. Results showed that the total amount of solid-bound Zn decreased 10% after the inoculation. The decrease for the amount of Zn associated with carbonate, manganese (Mn) oxides, and organic matter fraction was from 9 to 26%. No significant change was observed for the total amount of Zn combined with solid phase of Red soil in the presence of rhizobia. However, the amount of specifically adsorbed and Mn oxides bound Zn decreased, while the amount of exchangeable Zn increased. Inoculation of rhizobia depressed the release of Cu to the soil solution and increased the total amount of Cu associated with solid phase in Cinnamon soil. The increase for the amount of exchangeable Cu and the Cu in fractions of carbonate, Mn oxides, and organic matter ranged from 20 to 54%. There was no significant change for the level of Cd in the solution in both soils after rhizobia inoculation. The amount of Cd in the fractions of exchangeable and organic increased 22 and 11%, while that in the fractions of specific and Mn oxides decreased 14 and 29%, respectively. The different influence of rhizobia on the distribution of three heavy metals in two soils was mainly ascribed to the growth status and pH changes exerted by the metabolites of rhizobia. These data are helpful for the understanding of the chemical behavior and biogeochemical cycle of heavy metals affected by microorganisms in soil environment, which is fundamental for heavy metal bioremediation.

Chemical fractions of copper and zinc in organic‐rich particles from aqueous extracts of a metal‐contaminated granite soil

Abstract Chemical fractions of copper (Cu) and zinc (Zn) in the organic‐rich particles collected from filtered aqueous extracts (<20 μm) of an acid soil were determined. A sequential extraction procedure was used to partition the particulate Cu and Zn into four operationally defined chemical fractions: adsorbed (ADS), iron (Fe) and manganese (Mn) oxides bound (FeMnOX), organic matter bound (OM) and residual (RESD). Total extractable concentrations of Cu and Zn in the fine particles were higher than their total concentrations in the original bulk soil. The concentration of particulate Cu was usually much higher than that of particulate Zn. Addition of lime stabilized sewage sludge cake and/or inorganic metal salts markedly increased the concentrations of particulate Cu and Zn in aqueous extracts, especially from limed soil. The proportional distributions of particulate Cu and Zn were quite similar. The two particulate metals were present predominantly in the ADS and FeMnOX fractions, with less (about 20%) ...

Prevision de la biodisponibilité du cuivre en sols de craie. Partie II: Relation avec le fractionnement du cuivre

Abstract The bioavailability of copper is usually measured by chemical reagents such as EDTA. However, evidence of cupric deficiency for plants may be observed without the chemical test for it. Thus, the aim of this study was to apply classical sequential extraction procedures, used in environmental studies, in order to obtain a chemical fractionation of copper and to examine the possible relations between these fractions and the bioavailability of copper. The study was performed on calcareous soil samples collected in Eastern France and corresponding to an agronomical assay to study copper deficiency. The results of the copper fractionation were described in a first paper. In this paper, the possible relations between copper fractionation and grain yields obtained in the plots of the agronomical assay will be discussed. From a statistical point of view, there was no significant correlation between the copper fractions and yields, but significant relations between sampling year or sampling location and yi...

Chemical fractionation of copper, lead and zinc in ombrotrophic peat

Measurement of operationally defined chemical fractions in ombrotrophic peat samples provides information not obtained by total metal extractions. Examination of such sequential data permits interpretation of process dynamics. Results for copper, lead and zinc chemical fractionation of peat profiles from Ringinglow Bog, near Sheffield, Great Britain, are reported and discussed. Lead and zinc share similar patterns of partitioning. A considerable proportion of these records is in a form predisposed to transformation and mobilisation. In contrast, much of the copper is comparatively immobile, it being associated with the more chemically intractable fractions. The results suggest that peat copper deposition records may be used for reconstruction of pollution history. The use of lead and zinc records for these purposes is problematic.