ota pesticides and heavy metals contamination in cocoa

... fraction whereas Cu is mainly in the strongly bound organic and residual phases Hewitt and Candy (1990), examined levels of Pb, Cd and Zn in soil and dust samples collected in and around the city ... water supplies HEAVY METAL CONTAMINATION IN SOILS OF URBAN HIGHWAYS 313 Conclusions Heavy metal contamination in soils taken from along I-75, Cincinnati, Ohio, is very high in the top 15 cm ... of swelling clay in the soil, in this particular case, clay mineralogy is not important in the binding of the heavy metals, whereas the positive correlation of metals with organic carbon indicates...

Ngày tải lên: 16/03/2014, 00:25

... as initial concentration of water quality item at IN, chemical property for charcoal and heavy metals in soil and water, and so on Since heavy metals are known to be transported in water combined ... and heavy metals (chromium = Cr, iron = Fe, lead = Pb and zinc = Zn) in the water samples were analyzed in the laboratory In this report we analyzed and discussed mainly total elements including ... containing wood charcoal as an absorbent was designed, and its ability to remove organic matter, nutrients, and heavy metals in a test paddy field was investigated The following results were obtained:...

Ngày tải lên: 05/09/2013, 09:38

... Smelter waste Pb smelter waste Mine waste Smelting waste Refining waste Mine tailings Mine tailings Mine tailings Mine tailings Mine tailings Refining waste Mine tailings Soil profile metal distribution ... BY MINING AND SMELTING 93 Mineralogical Properties and Metal Transport Mineralogical methods can be used to estimate potential release and transport of metals from mining and smelting wastes In ... CONTAMINATED BY MINING AND SMELTING 107 Paulson, A.J 1997 The transport and fate of Fe, Mn, Cu, Zn, Cd, Pb, and SO4 in a groundwater plume and in downstream surface water in the Coeur d’Alene mining...

Ngày tải lên: 12/08/2014, 02:20

... 2001 2:33 PM 116 HEAVY METALS RELEASE IN SOILS be increasing and the point that represents the state of the system will be moving up and to the left, toward an equilibrium point on the isotherm ... places it in region II, the solution concentration will be increasing and the sorbed concentration will be decreasing and the point that represents the state of the system will be moving down and to ... Monday, May 7, 2001 2:33 PM 124 HEAVY METALS RELEASE IN SOILS Figure 5.17 Phase plane diagram of the metal in solution and sorbed on the solid (including both isotherm and kinetics) We can very clearly...

Ngày tải lên: 12/08/2014, 02:20

... PM 150 HEAVY METALS RELEASE IN SOILS THE PARTITIONING COEFFICIENT: DEFINITION The partitioning coefficient has been widely used in modeling the fate and transport of metals (and also other inorganic ... partitioning of these metals SUMMARY AND CONCLUSIONS Soil pH and organic matter are the two most important parameters determining metal partitioning and aqueous speciation in soils By incorporating ... change and metal-ion activity if dissolved OM and particulate OM dominate metal binding in solution and to the soil solid phase This postulation assumes that metal binding between solid and dissolved...

Ngày tải lên: 12/08/2014, 02:20

... protein incorporation (Lewis, 1976) In nonaccumulator plants, devoid of this mechanism, Se is incorporated into proteins, resulting in an alteration or inactivation of the protein structure and ... Jayaweera and Biggar (1996) showed that changes of Eh and pH can induce several transformations of Se in soil and affect Se release into drainage and groundwater systems During soil reduction, the total ... reduced and the bioavailability of selenium in the environment might increase and induce groundwater and food chain contamination Our studies emphasize the important role of soil organic matter in...

Ngày tải lên: 12/08/2014, 02:20

... gold mine heavily polluted by arsenic due to anthropogenic sources: pyrite and arsenopyrite oxidation On this site, mining activities started in the beginning of the century and ceased in the ... Speciation in Soils and Porewaters In natural systems, As may occur in four oxidation states: (–3), (0), (+3), and (+5) Arsenate (As(V)) and arsenite (As(III)) are the main forms in soils (Harper and ... As extracted also increased with increasing carbonate concentrations Arsenic-Bearing Phases in Mine Sites Some studies reported that, in As-contaminated soils, the primary As mineral assemblage...

Ngày tải lên: 12/08/2014, 02:20

Ngày tải lên: 13/11/2014, 09:58

... pathways of As and Cu contaminations into farmlands from the mining areas were indicated In the paddy fields around the tin mining area, the main pathway of the As and Cu contaminations were through ... tungsten mining areas 3.2 As and Heavy Metals in Soils Total contents of As and heavy metals (Cd, Cr, Cu, Mn, Ni, Pb and Zn) in the collected soils and their pH EC (dS m−1) Soils from the tin mining ... degree of contamination in agricultural soils and waters by toxic elements (As, Cd, Cr, Cu, Mn, Ni, Pb and Zn) and to clarify the contaminant pathways from the tin and tungsten mining areas, and (2)...

Ngày tải lên: 15/12/2017, 23:57

... the vitamins (retinol, tocopherol and cholecalciferol), and trace elements and heavy metals (Zn, Cu, Fe, Cd, Pb and Mn) in patients with CAD and the control group are shown in Table Compared ... levels and mortality Arch Intern Med 2002; 162: 2443-2449 31 Rock E, Winklhofer-Roob BM, Ribalta J, et al Vitamin A, vitamin E and carotenoid status and metabolism during ageing: functional and ... important in preventing the peroxidation of LDL and this action could be paramount in the prevention of atherosclerosis As lypophilic molecules, vitamin E and beta-carotene are incorporated into the...

Ngày tải lên: 25/10/2012, 10:51

... baseline carboxyhemoglobin of non-smoking firemen and smoking firemen A consistent increase in mean COHb levels after exposure to smoke was seen in both non-smoking and smoking men, but the mean increase ... carboxyhemoglobin readings were collected during training exercises The mean and median carboxyhemoglobin levels were 1% The maximum value in a firefighter wearing self-contained breathing apparatus ... carboxyhemoglobin [8] Measurements of serum iron and total iron binding capacity are widely used in the diagnosis and treatment of iron deficiency anemia and chronic inflammatory disorders [9] The clinical...

Ngày tải lên: 20/06/2014, 00:20

... Metal Contaminated Soils, EPA-542-R-97–004, USEPA, Washington, D.C., 1997 Forstner, U., Land contamination by metals: Global scope and magnitude of problem, in Metal Speciation and Contamination ... stability and transportability Settling rate experiments (Figure 2.2) indicated a decline in the concentration of kaolinitic colloids remaining in suspension at pH

Ngày tải lên: 11/08/2014, 10:22

... performed a great deal of work since Pauling3 introduced the basis for explaining mineral structure and reactivity Our aims are to provide insight into the main processes that control the proton ... resulting value for ∑s j int is 2.4 and thus LogK H = −7.9 In the case of the hydroxo group, there are two Si-O bonds, and one H donating and one H accepting bond Therefore, ∑s j int = and LogK ... pioneering works in applying Gouy-Chapmann and Stern models to kaolinitic soils Since then, many articles in which modeling is performed have appeared in the literature.26,40–44 More recently, and...

Ngày tải lên: 11/08/2014, 10:22

... interested in bonding NOM to soil minerals Al3+ and Fe3+ are thought to control this strong adsorption interaction, and bonding should be similar between NOM and these two metals We are currently beginning ... Kubicki, J.D and Bleam, W.F., An introduction to molecular modeling, in Molecular Modeling of Clays and Mineral Surfaces, Kubicki, J.D and Bleam, W.F., Eds., Clay Minerals Society, in press 18 ... acids to mineral surfaces and their role in contaminant binding, Sci Total Environ., 118, 413, 1992 31 Myneni, S.C.B et al., Imaging of humic substance macromolecular structures in water and soils,...

Ngày tải lên: 11/08/2014, 10:22

... crystalline and of mixed oxidation state (Hem and Lind, 1983; Murray et al., 1985; Adams and Ghiorse, 1988; Wehrli et al., 1992; Mandernack et al., 1995; Mandernack et al., 1995) Investigations using ... mediated mineral formation: Insights into manganese(II) oxidation from molecular genetic and biochemical studies, in Geomicrobiology: Interactions Between Microbes and Minerals, Banfield, J.F and Nealson, ... predictions for the individual oxides and assuming additivity of their Langmuir isotherms (compare columns to in Tables 7.4 and 7.5) These results suggest that interactions between the Mn and Fe oxides...

Ngày tải lên: 11/08/2014, 10:22

... successful in identifying Zn-bearing phases in the subsoil, indicating that Zn was not found in abundant portions in any one phase Aluminum, Si, and Fe in the maps in the subsurface soil indicated ... anthropogenic and natural input of heavy metals has established the need to investigate and comprehend metal–soil interactions The pathways for heavy metal introduction into soil and aquatic environments ... are in the left panel (solid line = raw data and dashed line = LCF result) and the corresponding radial structure functions (solid line = raw data and dashed line = shell fitting result) in the...

Ngày tải lên: 11/08/2014, 10:22

... 56, 1004, 1992 35 Kretzschmar, R and Voegelin, A., Modeling competitive sorption and release of heavy metals in soils, in Heavy Metals Release in Soils, Selim, H.M and Sparks, D.L., Eds., CRC Press, ... G.Y., and Liu, J.C., Solubility of heavy metals in a contaminated soil: Effects of redox potential and pH, Water Air Soil Pollut., 90, 543, 1996 11 Davranche, M and Bollinger, J., Heavy metals ... important in uence on the changes in the solubility of Mn and other trace metals under reducing conditions for these soils In certain situations, it will be necessary to include specific adsorption in...

Ngày tải lên: 11/08/2014, 10:22

... Fe, Al and other trace metals) and organic and inorganic pollutants in soils (Qualls and Haines, 1991; McCarthy and Zachara, 1989; Kaiser and Zech, 1998; Berggren et al., 1990; Maxin and Kögel-Knabner, ... and sludge DOM, respectively, in calcareous soil, and correspondingly 1.5% and 6.8% in acidic sandy soil calculated using the linear regression equations obtained in Figure 10.5 When DOM concentration ... peat, and sewage sludge (Slu) a peak at 1050 to 1130 cm−1 (C-N stretch in amino acid and C-O stretch in polysaccharides and carboxyl); and a sharp peak at 620 to 700 cm−1 ( C-H bending in aromatic...

Ngày tải lên: 11/08/2014, 10:22

... altering the system during the sampling and handling processes before analysis.25 11.2.3 LASER DOPPLER VELOCIMETRY AND PARTICLE CHARGE Evaluating particle surface charge is critical to understanding ... separates containing layer silicates and iron and aluminum oxides, Soil Sci Soc Am J., 56, 1074, 1992 Golden, D.C and Dixon, J.B., Silicate and phosphate in uence on kaolin-iron oxide interactions, ... McCarthy, J.F and Degueldre, C., Sampling and characterization of colloids and particles in groundwater for studying their role in contaminant transport, in Environmental Particles, Buffle, J and van...

Ngày tải lên: 11/08/2014, 10:22