heavy metals in soils alloway 1995

... Settling rate experiments (Figure2.2) indicated a decline in the concentration of kaolinitic colloids remaining insuspension at pH <5.5 compared to the illitic and montmorillonitic colloids, in ... have increased the soluble metal load These findings clearly demonstrate the role of colloid mineralogical composition on their ability to induce and mediate the transport of heavy metals in subsurface ... and mineralogical properties are also reported in Table 2.1 2.3.3 L EACHING E XPERIMENTS Four soil monoliths from each soil were used in the leaching experiment Before initiating the contamination

Ngày tải lên: 11/08/2014, 10:22

... another interact through covalent terms. Choosing the atomic charges remains an important step in developing an interatomic potential, however. Charges are either determined empirically by adjusting ... available to interested researchers include GAMESS (see Quantum Chemistry Program Exchange, Indiana University), Spartan (Wavefunc- tion, Inc.), Jaguar (Schrodinger, Inc.), Q-CHEM (Q-Chem, Inc.), Parallel ... of copper in the environment.86–88 The main thrust of our research will be trying to incorporate mineral surfaces into the aqueous-phase models we have presented here Generating accurate

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 ... examined the effect of copper concentration on Mn oxidation rates by L discophora SS1 using the controlled bioreactor and defined medium described above In the bioreactor experiments copper inhibited ... catalysis of Mn oxidation For example, recent investigations in a wetland in New York State found many different genetic strains of Leptothrix, each exhibiting different rates of catalysis of Mn oxidation

Ngày tải lên: 11/08/2014, 10:22

... 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 ... other minerals in the matrix which may cause fluorescence, resulting in an interference with the spectrum of the central element of interest (e.g., for Co and Ni in samples containing Fe oxides in ... 8 Zinc Speciation in Contaminated Soils Combining Direct and Indirect Characterization Methods Darryl Roberts, Andreas C. Scheinost, and Donald L. Sparks CONTENTS 8.1 Introduction

Ngày tải lên: 11/08/2014, 10:22

... dissolved by increasing concentrations of a reducing agent The desta-bilization of Fe and Mn oxides following the addition of a reducing agent to a contaminated soil caused an increase in the soluble ... of Cd and Zn decreased following saturation, and Ni decreased in two of the three soils These decreases in metal solubility coincided with a pH increase in all three soils, and were attributed ... The major findings are summarized here The soluble concentrations of Mn, Zn, Ni, and Sr increased in both soils following reduction Total electrolyte concentration also increased following reduction,

Ngày tải lên: 11/08/2014, 10:22

... to the mineral surfaces Therefore,composting organic wastes would increase the adsorption of DOM on soils because of the increase in aromatic carbon-containing compounds after composting (Liang ... Despite intensive research in the past decade, most of the studies done in thelaboratory have not yet been investigated in the field In fact, many researches showthat organic C and contaminants in ... have similar binding affinity with each soil interms of 1/n, but Cd sorption exhibited a higher k value than Zn sorption in eachsoil, especially in the acidic sandy loam, indicating that a higher

Ngày tải lên: 11/08/2014, 10:22

... change in mobility as a function of minorchanges in cell position is quite great in the region surrounding the stationary layer.Taking numerous measurements across the capillary (i.e., EM fingerprinting) ... light-scattering instruments, is similar to the refractive index of phyl-losilicate clays Light scattering from an intense, coherent, monochromatic beam, usually a He-Ne or Ar laser in most instruments, ... scattering, quantifies the particle motion (Brownian motion) by measuring the signal intensity at a given instance and comparing that with signals obtained at successively longer time intervals,

Ngày tải lên: 11/08/2014, 10:22

... contents in soils (Huang et al 2007; Khan et al 2008; Zhao et al 2007) The total contents of heavy metals provide information on the accumulation of heavy metals in soils However, the mobility of metals ... industrial activities including copper and lead casting, phosphorous fertilizer production, chemical manufacturing, etc., has been indicated to have introduced heavy metals into water and soil ... studies mainly addressed total metal concentrations in the soils (Ho and Egashira 2001; Trinh and Wada 2004; Le 2002); no detailed investigation of contents and chemical forms of heavy metals in soils

Ngày tải lên: 14/12/2017, 17:50

... Contaminant concentration versus pumping volume showing tailing and rebound effects (From USEPA 1996) Investigation of the nonequilibrium transport in soils is a multi-disciplinary endeavor The influence ... research directions in future.Heavy Metals and SOiÌS - 2S nọ 6Cadmium (Cd) and copper (Cu) are of interest in this study, since they are included in the list of priority metals because of ... principal primary minerals (i.e rock-forming minerals) are primary silicates including quartz, feldspars, micas, etc; the secondary minerals (i.e products of weathering of primary minerals) include layer

Ngày tải lên: 02/10/2024, 01:36

... the important processing steps of black tea in Bangla-desh In particular, it may occur during the CTC rolling steps involved in the production of black tea However, this finding is lower than the ... methods in Bangladesh for the digestion of tea to determine heavy metals Moreover, to our knowl-edge, there is limited data on the amount of heavy metals in fresh tea leaves, processed tea or soils ... by dividing the concentration of the heavy metal in pre-sent in the tea by that of the total heavy metal concentra-tion in the soil [31]: Results and discussion Heavy metal contents in fresh

Ngày tải lên: 29/05/2020, 14:09

... wetland plants to high concentrations of heavy metals in their tissues as well as in soil This chapter presents the results of investigations of these heavy metals in the wetland and the rates of filtration ... maximum of 1798 g-dm/m2 Dominant plants in each plot are given in Appendix Table A9.16 Concentration of Heavy Metals in Plant Tissues The concentrations of metals found in plants ranged from 25 ... 0.0 Zinc L1401-frame-C9 Page 102 Monday, April 10, 2000 9:56 AM Trang 8LEAD AND ZINC RETENTION IN THE BIALA RIVER WETLAND OF POLAND 103Zinc and lead in wetland soils were compared with soils

Ngày tải lên: 18/06/2014, 19:20

... Trang 2122 HEAVY METALS IN THE ENVIRONMENT: USING WETLANDS FOR THEIR REMOVALrecognized as part of the economy through their work in filtering toxic substances such as heavymetals Increasingly, wetlands ... discounting/incomecapitalization formula is given in Appendix A11 METHODS The first step in valuing the work of the wetland in retaining lead was to quantify the amount of lead actually held in the ... Appendix E) Assuming a linear rate of increase in battery processing by Sapp Battery from zero at thebeginning of 1970 (when the plant opened) to a peak of 50,000 batteries per week in 1979 (Watts,1984),

Ngày tải lên: 18/06/2014, 19:20

... ANALYSIS Mining Law of 1972 The statutes that govern lead mining today date back to the General Mining Law of 1972. In passing this law, Congress intended to protect the rights of individuals ... benefits of mining and selling lead and lead products were large, and the cost of damaged ecosystems seemed minor. The regulations governing the mining and processing of lead were few, as seen in Table ... purposes in the economy. But, because the economic drain from waste is small in the beginning and the price of obtaining new resources is low, recycling is slow to develop and the benefits of recycling

Ngày tải lên: 18/06/2014, 19:20

... flow of incident light Jw = water inflow (rain plus streams) “K”s are coefficients evaluated in Appendix Table A8.2 L = outflow of lead remaining in water L0 = lead concentration in inflowing waters ... calculated using three indices The Shannon diversity index is given by where H ′ is the information in bits per individual, pi is the proportion of individuals in a sample belonging to taxon ... The leaf area index of floating vegetation was measured using a line-intercept transect 5 m in length The intercept lengths were recorded for individual leaves of Nymphaea Totals of intercept lengths

Ngày tải lên: 18/06/2014, 19:20

... low intakes (deficiency) or excess intakes (toxicity) In deriving the limits of the AROI, uncertainties in the data as well as the variability in the intakes of individuals within ... leading to reduced availability Copper uptake in the gut is inhibited by high zinc intakes Both a direct interaction and an interaction mediated by metallothionein induction may explain this ... transmitted in any form or by any means, electronic or mechanical, including photocopying, microfilming, and recording, or by any information storage and retrieval system, without permission in writing

Ngày tải lên: 11/08/2014, 15:20

... direct determination of heavy metals speciation invarious type of matrices The molecular-level speciation analysis of arsenic andlead in mine tailings, and selenium in contaminated soils, has been ... the environmental chemistry of heavymetals results from continuing improvements in trace element analytical research.This is particularly true in the fields of heavy metals speciation analysis andmicroscopic ... for heavy metals analysis in groundwater samples (25) U.S EPAmethod 200.8 provides procedures for determination of dissolved elements ingroundwaters, surface waters, and drinking water using

Ngày tải lên: 11/08/2014, 15:20

... new finding is the linkage between heavy metal–induced toxicity and the function of the quitin-proteasome system in the cell The ubiquitin-proteasome system is in-volved in regulating protein stability ... mitochondria again depending on their membrane potential (41).There are intracellular changes in Ca2 ⫹concentration in response to toxicinsult as heavy metals are postulated to interfere with the Ca influx ... certain heavy metals such as cadmium inter-act with intracellular regulatory systems that control expression of genes andintracellular stability of newly synthesized proteins An interesting new

Ngày tải lên: 11/08/2014, 15:20

... Experimental studies inanimals suggest that the absorption of indium from the gastrointestinal tract isabout 2% (9) Since, like aluminum, indium occurs in the earth’s crust in silicates,such as ... indium,⬍⬍1%, occur in aluminum and zinc ores In contrast tocadmium, indium has few industrial or medical applications and, in consequence,it has attracted little environmental or toxicological interest ... of information on its concentrations in Copyright © 2002 Marcel Dekker, Inc Trang 6natural waters or in plant, animal, or human tissues The daily intake of zirconiumin the human diet and drinking

Ngày tải lên: 11/08/2014, 15:20

... production using metals, such as for certain chromiumpigments or nickel-containing catalysts, have been associated with human cancer(6) Individuals involved in certain mining processes and in iron ... beessential nutrients Some essential metals can even be carcinogenic in humansor animals like, for instance, chromium or zinc However, since many metals areessential in living systems, homeostasis is ... the text includes data from refs 137–140. b Defined as: im, intramuscular; inh, inhalation; ios, intraosseous; ip, intraperitoneal; ipro, intraprostatic; ir, intrarenal; ites, lar; iv, intravenous;

Ngày tải lên: 11/08/2014, 15:20

... As in both provinces is geogenic In the Kuitun area ofXinjiang province of China, endemic arsenicosis, fluorosis, and combined As andfluoride poisoning was encountered where nearly 102 drinking ... limit for As ingroundwater was 50µg/L, but in view of recent incidences of As poisoning in Trang 15the Indian subcontinent, a decrease in the groundwater As concentration to 5–10µg/L is being considered ... oxidation(?) in alluvial sedi-ments China, Xinjiang In- 4800 km2 Shallow/deep ⬍50–1860 Reducing environ- 138,139,140,201 in mine tailingsThailand (10 dis- 10 districts Shallow 120–6700 Oxidation of mine

Ngày tải lên: 11/08/2014, 15:20