Adsorption and redox reactions of heavy metals on synthesized Mn oxide minerals

2007 ◽  
Vol 147 (2) ◽  
pp. 366-373 ◽  
Author(s):  
Xiong Han Feng ◽  
Li Mei Zhai ◽  
Wen Feng Tan ◽  
Fan Liu ◽  
Ji Zheng He
Keyword(s):  
Heavy Metals ◽  
Redox Reactions ◽  
Mn Oxide ◽  
Oxide Minerals

The influence of pH on the synthesis of mixed Fe-Mn oxide minerals

Clay Minerals ◽  
1990 ◽  
Vol 25 (4) ◽  
pp. 507-518 ◽  
Author(s):  
M. H. Ebinger ◽  
D. G. Schulze
Keyword(s):  
Iron Oxides ◽  
Mole Fraction ◽  
Unit Cell ◽  
Mn Oxide ◽  
Cell Dimensions ◽  
The Mean ◽  
Mn Substitution ◽  
Oxide Minerals ◽  
Unit Cell Dimensions ◽  
Influence Of Ph

AbstractMn-substituted iron oxides were synthesized at pH 4, 6, 8, and 10 from Fe-Mn systems with Mn mole fractions (Mn/(Mn + Fe)) of 0, 0·2, 0·4, 0·6, 0·8, and 1·0, and kept at 50°C for 40 days. The Mn mole fraction in goethite was <0·07 at pH 4 but increased to ∼0.47 at pH 6. Goethite and/or hematite formed in Fe and Fe + Mn syntheses at pH 4 and pH 6 at Mn mole fractions ≤0·8, and at Mn mole fractions ≤0·2 at pH 8 and pH 10. Hausmannite and jacobsite formed at pH 8 and pH 10 at Mn mole fractions ≥0·4. In the pure Mn syntheses, manganite (γ-MnOOH) formed at pH 4 and pH 6, whereas hausmannite (Mn3O4) formed at pH 8 and pH 10. As the Mn substitution increased, the unit-cell dimensions of goethite shifted toward those of groutite, and the mean crystallite dimensions of goethite decreased.

scholarly journals Immobilization Potential of Cow Manure for Heavy Metal Remediation from Refuse Dump Soil

2021 ◽  
pp. 44-55
Author(s):  
Ezeudu Emeka Christian ◽  
Oli Christian Chukwuemeka ◽  
. Enenche ◽  
Elaigwu Daniel ◽  
Anekwe Ozioma Juliana ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Ricinus Communis ◽  
Cow Manure ◽  
Industrial Chemistry ◽  
Refuse Dump ◽  
Anambra State ◽  
Mn Oxide ◽  
Greenhouse Study ◽  
Mobility Factor ◽  
Heavy Metal Remediation

Aims: The present study investigated the effect of cow manure amendment on fractionation and availability of some heavy metals (Cd, Cu, Cr, Mn, Pb and Zn) in refuse dump soil. Study Design: A greenhouse study experiment was conducted to determine the uptake of the metals by Ricinus communis in dump soil treated with 0%, 5%, 10% and 20% cow manure. Place and Duration of Study: The study was carried out at the Department of Pure and Industrial Chemistry, Nnamdi Azikiwe University Awka, Anambra State, Nigeria, between May and October 2018. Methodology: Experimental pots were filled with 2.0kg refuse dump soil in a green house and treated with 5%, 10% and 20% of Cow manure in three replicates per treatment. The seeds of Ricinus communis were planted in each pot and analysed after 12 weeks of planting for heavy metals using AAS. Sequential extraction was carried out on the treated soil after the harvest with each extract further analysed for heavy metals using AAS. Results: Application of cow manure significantly (p ˂ 0.05) affected the redistribution and the mobility of the heavy metals in the dump soil; as the concentration of the amendment increased, heavy metals in the mobile fractions reduced. 20% amendment had the best immobilization effect as the mobility factor decreased with increasing manure amendment. The mobility factors at 20% amendment were 18.34%, 15.82%, 5.23%, 15.86%, 25.56% and 12.81% for Cd, Cr, Cu, Mn, Pb and Zn respectively with the general trend of metal forms given as: residual > bound to organic > bound to Fe-Mn oxide > bound to carbonate > exchangeable. Conclusion: Cow manure amendment of the dump soil decreased the availability of heavy metals for plant uptake; and the metal uptake generally decreased as percentage amendment increased. Cow manure is therefore a good immobilizing agent for remediation of Cd, Cr, Cu, Mn, Pb and Zn in polluted soils.

Speciation Analysis of Heavy Metals of Core Amuta Sediments in Lianhua Lake

2010 ◽  
Vol 113-116 ◽  
pp. 716-719
Author(s):  
Fu Hua Xuan ◽  
Shu Ying Zang
Keyword(s):  
Heavy Metals ◽  
Speciation Analysis ◽  
Chemical Forms ◽  
Organic Sulfide ◽  
The Core ◽  
Mn Oxide ◽  
Binding Forms ◽  
Residue Fraction

The BCR-SEP method was used to determine the binding forms of heavy metals in Amuta Lake(AMT) in this paper. The chemical forms of heavy metals, namely extractable fractions or valid fractions, including exchangeable-carbonate fraction, Fe-Mn oxide fraction and Organic-sulfide fraction .The results of the partitioning study indicated that in the core AMT sediments, Cr, Fe and Ni are mainly associated with the residue fraction, Cu is mainly concentrated in the Fe–Mn oxide fractions and residue fraction, Mn is concentrated in the exchangeable-carbonate fraction and residue fraction. Zn is concentrated in organic-sulfide fraction and residue fraction.

Oxidation of anthracene using waste Mn oxide minerals: The importance of wetting and drying sequences

2012 ◽  
Vol 205-206 ◽  
pp. 126-130 ◽  
Author(s):  
Catherine Clarke ◽  
Janette Tourney ◽  
Karen Johnson
Keyword(s):  
Wetting And Drying ◽  
Mn Oxide ◽  
Oxide Minerals

A mechanism for the formation of the mineralized Mn deposits at Merehead Quarry, Cranmore, Somerset, England

2006 ◽  
Vol 70 (6) ◽  
pp. 629-653 ◽  
Author(s):  
R. Turner
Keyword(s):  
Heavy Metals ◽  
Closed System ◽  
Oxide Coating ◽  
Local Environment ◽  
Mississippi Valley ◽  
Secondary Minerals ◽  
Mn Oxide ◽  
Uplift And Erosion ◽  
First Time ◽  
Hydrothermal Event

AbstractMississippi Valley type galena deposits emplaced into Carboniferous limestones throughout the Mendip Hills during the late Permian or Triassic period were locally exposed to the action of seawater during the Jurassic period following regional uplift and erosion of the intervening strata. Oxidation of galena initiated the deposition of manganate minerals from the seawater, and these adsorbed heavy metals from both the seawater and local environment. A subsequent hydrothermal event heated the lead-manganate deposits causing decomposition of the galena and creating the conditions which led to the formation of the suite of unusual secondary minerals – including a number of rare oxychlorides – now found at Merehead. Heating of the manganate phases converted them to Mn oxides and released the entrained heavy metals which were then incorporated into unusual mineral phases. The impervious Mn oxide coating which enclosed the cooling Pb-rich areas isolated them chemically, leading to closed-system behaviour. The high-T phases at Merehead are similar to those found in the Pb-bearing silicic skarns at Långban, whilst the suite of secondary minerals which evolved in the closed-system environments bears striking similarities to the ‘anomalous sequence’ of minerals found at the Mammoth-St. Antony Mine. The complexity of these formation processes probably explains the rarity of Mendip-type Pb-Mn deposits. The collective importance of the disconformity, the hydrothermal event, and subsequent sealing of the deposits are recognized for the first time, and the temperature of the hydrothermal event is shown to have been much greater than has heretofore been realized. Silurian volcanic strata underlying the Carboniferous limestones which have previously been assumed to be the source of heavy metals are shown to have been uninvolved in the process.

scholarly journals Mineralogical Characterization of Manganese Oxide Minerals of the Devonian Xialei Manganese Deposit

Minerals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1243
Author(s):  
Sida Niu ◽  
Liqun Zhao ◽  
Xiaoju Lin ◽  
Tong Chen ◽  
Yingchao Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Manganese Oxide ◽  
Spherical Particles ◽  
Manganese Ore ◽  
Manganese Deposit ◽  
Mineralogical Characterization ◽  
Mn Oxide ◽  
Oxide Minerals ◽  
Scanning Electron

The Guangxi Zhuang Autonomous Region is an important manganese ore district in Southwest China, with manganese ore resource reserves accounting for 23% of the total manganese ore resource reserves in China. The Xialei manganese deposit (Daxin County, Guangxi) is the first super-large manganese deposit discovered in China. The Mn oxide in the supergene oxidation zone of the Xialei deposit was characterized using scanning electron microscopy (SEM), energy spectrometer (EDS), transmission electron microscopy (TEM, HRTEM), and X-ray diffraction analysis (XRD). The Mn oxides have a gray-black/steel-gray color, a semi-metallic-earthy luster, and appear as oolitic, pisolitic, banded, massive, and cellular textures. Scanning electron microscopy images show that the manganese oxide minerals are present as fine-spherical particles with an earthy surface. TEM and HRTEM indicate the presence of oriented bundled and staggered nanorods, and nanopores between the crystals. The Mn oxide ore can be classified into two textural types: (1) oolitic and pisolitic (often with annuli) Mn oxide, and (2) massive Mn oxide. Pyrolusite, cryptomelane, and hollandite are the main Mn oxide minerals. The potassium contents of cryptomelane and pyrolusite are discussed. The unit cell parameters of pyrolusite are refined.

Assessment of sediment toxicity by metal speciation in different particle-size fractions of river sediment

2003 ◽  
Vol 47 (7-8) ◽  
pp. 233-241 ◽  
Author(s):  
J.G. Lin ◽  
S.Y. Chen ◽  
C.R. Su
Keyword(s):  
Heavy Metals ◽  
Particle Size ◽  
Aquatic Ecosystem ◽  
Metal Speciation ◽  
Sediment Toxicity ◽  
Clay Fraction ◽  
Potential Toxicity ◽  
Size Fractions ◽  
Particle Size Fractions ◽  
Mn Oxide

Mobility and toxicity of metals associated with sediments are generally affected by metal speciation and granular compositions. Due to the various speciation patterns of heavy metals in sediments, it is not reliable to assess the potential toxicity of heavy metals on the aquatic environment with the total concentrations of heavy metals in sediments. The purposes of this study were to investigate the distribution of metal speciation in different particle-size fractions of sediments collected from two rivers (the Ke-Ya River and Ell-Ren River) in Taiwan, and to assess their potential toxicity to the aquatic ecosystem. Metals in the exchangeable, carbonate-bound and Fe/Mn oxide-bound forms obtained by sequential extraction were considered to be mobile and related with anthropogenic pollution. The degree of metal pollution and potential toxicity of sediments were higher in the lower reaches of both rivers. The metal speciation in sediments had a bimodal distribution over particle-size fractions. Heavy metals were subject to accumulation in the silt/clay fraction (&lt;25μmm) and coarse sand (420-2,000μmm). By normalizing the sum of the exchangeable, carbonate-bound, and Fe/Mn oxide-bound metals, it suggested that the potential toxicity to the aquatic ecosystem was caused by the fine sediments as well as coarse sediments.

Adsorption and redox reactions of heavy metals on Fe–Mn nodules from Chinese soils

2005 ◽  
Vol 284 (2) ◽  
pp. 600-605 ◽  
Author(s):  
Wenfeng Tan ◽  
Fan Liu ◽  
Xionghan Feng ◽  
Qiaoyun Huang ◽  
Xueyuan Li
Keyword(s):  
Heavy Metals ◽  
Redox Reactions

scholarly journals Chemical Speciation and Potential Mobility of some Metals of Selected Farmland in Kogi State, North Central Nigeria

2021 ◽  
Vol 28 (1) ◽  
pp. 48-55
Author(s):  
J.E. Emurotu
Keyword(s):  
Heavy Metals ◽  
Agricultural Soils ◽  
Metal Speciation ◽  
Residual Fraction ◽  
Food Crops ◽  
Residual Soil ◽  
North Central ◽  
Mn Oxide ◽  
Exchangeable Fraction ◽  
Potential Mobility

The contamination of agricultural soils with heavy metals is of concern because if the soil is contaminated, the metals can be transferred to food crops. The availability of these metals to food crops depends on the forms in which they are present in the soils. In this study, sequential extraction technique was applied to assess the exchangeable, carbonate-bound, Fe-Mn oxide bound, organic bound and residual fractions in the topsoil of farmlands in Kogi State, North Central Nigeria. Proportions in non-residual soil phases were 82.6 % Cd, 48.6 % Co, 72.5 % Cu, 73.2 % Ni, 41.9 % Pb, and 84.3 % Zn. Lead (Pb) and cobalt (Co) showed the highest phase of 58.1% and 51.4 %, respectively in the residual phase. The low concentration of lead in the non-residual fraction (41.9 %) and the highly mobileexchangeable phase and pH sensitive carbonate phase is an indication that there is no increase in anthropogenic input of Pb into the environment. Cadmium, zinc and nickel are most abundant in exchangeable fraction and this can be of concern especially cadmium. Keywords: Heavy metals, Metal speciation, Farmlands, Food crops, Metal uptake

scholarly journals Fractional Characteristics of Heavy Metals Pb, Zn, Cu, and Cd in Sewer Sediment from Areas in Central Beijing, China

2016 ◽  
Vol 2016 ◽  
pp. 1-10
Author(s):  
Haiyan Li ◽  
Mingxiu Wang ◽  
Wenwen Zhang ◽  
Ziyang Zhang ◽  
Xiaoran Zhang
Keyword(s):  
Heavy Metals ◽  
High Risk ◽  
Inner City ◽  
Extraction Procedure ◽  
Pollution Assessment ◽  
Mn Oxide ◽  
Medium Risk ◽  
Functional Areas ◽  
Beijing China ◽  
Very High

To identify the distribution of heavy metals in sewer sediments and assess their potential harmfulness to the environment and human health, the occurrence of Pb, Zn, Cu, and Cd in the sewer sediment of six functional areas and two streets in an inner-city suburb of Beijing, China, was investigated by using a sequential extraction procedure. Results show that the concentrations of Cu, Zn, Cd, and Pb vary between 50 and 175, between 80 and 180, between 0.75 and 2.5, and between 20 and 110 mg/kg, respectively, and Fe-Mn oxide fraction is significant for all metals in sampling areas. Pollution assessment shows that 1–2% of Cu at Chegongzhuang Street and 1–3% of Zn at Fuwai Street in the exchangeable fractions are of low risk. 10–25% of Cd at six functional areas indicates medium risk. 40–60% of Pb at Fuwai Street existing in the exchangeable fractions is of high to very high risk. The sum of these metals associated with exchangeable, carbonate bound, and Fe-Mn oxide fractions is quite high; however, these three fractions represent the proportion of heavy metals that can be remobilized by changes in environmental conditions.

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