Speciation, reactivity and mobility of toxic elements in soil systems

Author(s):  
Ricardo Melamed
Keyword(s):  
2020 ◽  
Vol 3 (2) ◽  
Author(s):  
Cyril Ocheri ◽  
A. D. Omah ◽  
C. N. Mbah ◽  
R. E. Njoku ◽  
N. A. Urama ◽  
...  

Heavy metals pollution potential in National Iron Ore Mining Company, Itakpe was investigated. Two mining sites located at the east mining pits such as M3O, which is 370 m above sea level and M2O, which is 350 m above sea level were studied.  Sequential extraction techniques was utilised to examine the distribution effect of the heavy metals pollution potential on the environment. Twelve representative (six-soil, two-sediment, two-plant and two-water) samples were collected, pre-treated and prepared for this study. The atomic absorption spectrometer was used to analyse the concentration of the metals after the sequential and single-stage extractions were determined. Results showed that Chromium, Arsenic, Cadmium and Copper are more bioavailable in the study area than Lead and Iron. This findings indicate that human, animals and plants are exposed to toxic elements (metals and metalloids).


Infant’s feeding patterns are important for development and growth; therefore babies are very sensitive to toxic elements, mainly through their food, so in the present study, the concentrations and daily intake of some Toxic Elements (TEs); Lead (Pb), Arsenic (As), Cadmium (Cd), Mercury (Hg) and Aluminum (Al) were measured in different and random 60 dried infant foods {30 infant formula (0-6 months) and 30 milk-cereal based infant formula (6 months)} which obtained from various supermarkets and pharmacies. The analysis was done using Inductive Coupled Plasma - Mass Spectrometer (ICP-MS). It could be determined the lead, arsenic, cadmium, mercury and aluminum by mean values of 0.424±0.006, 0.205±0.003, 0.014±0.0001, 0.298±0.007and 0.464±0.029 mg/Kg in the examined infant milk formula samples and a ranged minimum to maximum concentrations of 0.114-0.177, 0.155-0.293, 0.014-0.015, 0.282-0.310 and 0.287-0.437 mg/kg, respectively in the examined milk-cereal based infant formula. Present study indicates that, the greater level of contamination of examined infant formula samples with toxic elements (lead and mercury) surpasses the maximum limit and Provisional Tolerable Daily Intake (PTDI) of these elements. Mercury is over PTDI (0.0005 mg/kg bw/day) in all milk-cereal based infant formula samples, also arsenic in all examined samples of this type of formula was exceed the maximum limit (0.05 mg/kg) of Indian standard. This investigation shows such types of infant formula need more amendment to set limit of more toxic metals for this sensitive group of population.


1993 ◽  
Author(s):  
Kara L. Olen ◽  
Richard J. Fragaszy ◽  
Michael R. Purcell ◽  
Kenneth W. Cargill

1997 ◽  
Vol 32 (3) ◽  
pp. 523-550
Author(s):  
S.N. Volkov

Abstract In urbanized geotechnical systems (UGSs), the majority of problems related to the ecological hydrochemistry of Cd, Pb, Ni and other heavy metals are the result of emergent characteristics of a system as a whole as opposed to individual pollution sources. In petrochemical UGSs, pollution of the environment from compounds containing methylating or alkylating agents results in an increase in the mobility of Cd, Pb, Ni, Cr and As. This process is controlled by environmental and microclimatic factors rather than by pollution sources. Under conditions of predominant dust and element effects, geo-chemically paradoxical associations of Cd with Ni, Mn and Cr can be formed in the main life support media in mining and metallurgical UGSs. Uncontrolled processes of hydrochemical interactions take place in complex multifunctional UGSs, leading to a change in speciation of heavy metals, particularly cadmium. This report is part of a 5-year study of the geotechnical systems in the Urals.


1995 ◽  
Vol 32 (3) ◽  
pp. 317-327 ◽  
Author(s):  
P. Cooper ◽  
B. Green

The UK Water Industry first became interested in Reed Bed Treatment Systems for sewage in 1985. Early problems were experienced with soil-based horizontal-flow systems of the Root Zone type. The problems were overcome by national co-ordination of a development programme and international co-operation by an EC Expert Contact Group. A number of different types of systems have now been developed and the systems are now being accepted. The paper reviews the development of these systems for secondary and tertiary treatment and nitrification and mentions development of systems for other forms of treatment. The design changes made to overcome the problems are described. These include the gradual move to the use of gravel-based systems because of the difficulty experienced with over-land flow in the soil systems. The sizing of the systems is described together with performance data for the original horizontal-flow and the more recently developed vertical-flow systems. Treatment at secondary and tertiary levels is illustrated and the potential for nitrification. Early problems with reed growth have been overcome by planting with port-grown seedlings. After 10 years the process is generally accepted by the Water Industry as an appropriate treatment for villages and there are now between 200 and 300 systems in operation.


2016 ◽  
Vol 41 (2) ◽  
pp. e12772 ◽  
Author(s):  
Chen Chen ◽  
Guitang Chen ◽  
Song Wang ◽  
Fei Pei ◽  
Qiuhui Hu ◽  
...  
Keyword(s):  

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