Chemical environments of deposition of ancient iron- and manganese-rich sediments and cherts

1999 ◽  
Vol 125 (1-2) ◽  
pp. 83-98 ◽  
Author(s):  
H.C. Dasgupta ◽  
V.V. Sambasiva Rao ◽  
C. Krishna
Keyword(s):  
Ancient Iron ◽  
Iron And Manganese

Colloidal systems in soils

1994 ◽  
Vol 52 ◽  
pp. 64-65
Author(s):  
J. Thieme ◽  
J. Niemeyer ◽  
P. Guttman
Keyword(s):  
Clay Minerals ◽  
Polymeric Materials ◽  
Spatial Arrangement ◽  
High Specific Surface Area ◽  
Turnover Rates ◽  
Colloidal Systems ◽  
Chemical Conditions ◽  
Aggregation Phenomena ◽  
Iron And Manganese ◽  
Soil Colloids

In soil science the fraction of colloids in soils is understood as particles with diameters smaller than 2μm. Clay minerals, aquoxides of iron and manganese, humic substances, and other polymeric materials are found in this fraction. The spatial arrangement (microstructure) is controlled by the substantial structure of the colloids, by the chemical composition of the soil solution, and by thesoil biota. This microstructure determines among other things the diffusive mass flow within the soils and as a result the availability of substances for chemical and microbiological reactions. The turnover of nutrients, the adsorption of toxicants and the weathering of soil clay minerals are examples of these surface mediated reactions. Due to their high specific surface area, the soil colloids are the most reactive species in this respect. Under the chemical conditions in soils, these minerals are associated in larger aggregates. The accessibility of reactive sites for these reactions on the surface of the colloids is reduced by this aggregation. To determine the turnover rates of chemicals within these aggregates it is highly desirable to visualize directly these aggregation phenomena.

Microstructure and Technology of Ancient Iron Axes Excavated from Suchon-ri, Gongju, Korea

2014 ◽  
Vol 52 (3) ◽  
pp. 225-231 ◽  
Author(s):  
Hyun Kyung Cho ◽  
Nam Chul Cho ◽  
Hun Lee
Keyword(s):  
Ancient Iron

The content of copper, zinc, iron and manganese in honey

2008 ◽  
Vol 21 (1) ◽  
pp. 77-80
Author(s):  
Andrzej Kot ◽  
Stanisław Zaręba
Keyword(s):  
Copper Zinc ◽  
Iron And Manganese

Chemical effects on UV irradiation absorption of fouled quartz sleeves in ultraviolet disinfection

2008 ◽  
Vol 8 (2) ◽  
pp. 217-222 ◽  
Author(s):  
Beibei Zhu Sun ◽  
Ernest Blatchley ◽  
Mike Oliver ◽  
Cheng Zheng ◽  
Kristofer Jennings
Keyword(s):  
Statistical Analysis ◽  
Uv Disinfection ◽  
Uv Absorbance ◽  
Ultraviolet Disinfection ◽  
High Chemical ◽  
Chemical Surface ◽  
Chemical Effects ◽  
Uv Transmittance ◽  
Main Effects ◽  
Iron And Manganese

The effects of foulant chemical composition on ultraviolet (UV) absorbance of fouled quartz sleeves in UV disinfection systems were studied. Statistical analysis was conducted to examine the effects of nine fouling chemicals on the UV transmittance changes of fouled quartz lamp sleeves. The results demonstrated that the main effects were attributable to surface concentrations of iron and manganese. The surface concentrations of calcium and copper had no significant effects on the UV absorbance of fouled sleeves. The interaction effects of copper with iron and magnesium with manganese were also revealed from the statistical analysis. The model is able to give reasonable predictions of the UV absorbance characteristics of foulants from other UV systems. However, several limitations of this model were identified. First, the model does not accurately predict the absorbance at relatively high chemical surface concentrations. Second, the model does not account for the possible effects of anions and organics on UV absorption of fouled quartz sleeves.

Investigation into Mechanisms of Microbial Effects on Iron and Manganese Transformations in Artificially Recharged Groundwater

1988 ◽  
Vol 20 (3) ◽  
pp. 47-53 ◽  
Author(s):  
Yan Bao-rui
Keyword(s):  
Groundwater Quality ◽  
Biochemical Reaction ◽  
Reaction Products ◽  
Injection Wells ◽  
Iron Bacteria ◽  
Sulphate Reducing Bacteria ◽  
Prevention And Treatment ◽  
Reducing Bacteria ◽  
Iron And Manganese ◽  
Microbial Effects

After artificial recharging of groundwater some problems occurred, such as changes in groundwater quality, the silting up of recharge (injection) wells, etc. Therefore, the mechanisms of microbial effects on groundwater quality after artificial recharging were studied in Shanghai and the district of Changzhou. These problems were approached on the basis of the amounts of biochemical reaction products generated by the metabolism of iron bacteria, sulphate-reducing bacteria, Thiobacillusthioparus, and Thiobacillusdenitrificans. The experiments showed that in the transformations occurring and the siltation of recharge wells, microorganisms play an important role, due to the various chemical and biochemical activities. A water-rock-microorganisms system is proposed, and some methods for the prevention and treatment of these effects are given.

ETERMINATION IRON AND MANGANESE CONTENT IN MOTOR FUELS

2017 ◽  
Vol 59 (2) ◽  
pp. 097-102
Author(s):  
Anastasiya A. Kotlova ◽  
◽  
Ilya A. Belous ◽  
Anastasiya V. Kiyashko ◽  
Roman S. Edigarev ◽  
...  
Keyword(s):  
Manganese Content ◽  
Motor Fuels ◽  
Iron And Manganese

scholarly journals Impact of ancient iron smelting wastes on current soils: Legacy contamination, environmental availability and fractionation of metals

2021 ◽  
Vol 776 ◽  
pp. 145929
Author(s):  
Adnane Amnai ◽  
Diane Radola ◽  
Flavien Choulet ◽  
Martine Buatier ◽  
Frédéric Gimbert
Keyword(s):  
Iron Smelting ◽  
Ancient Iron ◽  
Environmental Availability

The Vyredox and Nitredox Methods of in situ Treatment of Groundwater

1988 ◽  
Vol 20 (3) ◽  
pp. 149-163 ◽  
Author(s):  
Carol Braester ◽  
Rudolf Martinell
Keyword(s):  
Water Treatment ◽  
Surface Water ◽  
Traditional Method ◽  
Treatment Method ◽  
Nitrate Treatment ◽  
The Past ◽  
The World ◽  
Nitrate And Nitrite ◽  
Iron And Manganese

Nearly one fifth of all water used in the world is obtained from groundwater. The protection of water has become a high priority goal. During the last decades pollution of water has become more and more severe. Today groundwater is more and more used in comparison with surface water. Recently we have seen accidents, which can pollute nearly all surface water very quickly. Generally the groundwater is easier to protect, as well as cheaper to purify, and above all it is of better quality than the surface water. During the past two decades, alternatives to the traditional method of treating the water in filters have been developed, that is in situ water treatment i.e. the VYREDOX and NITREDOX methods. The most common problem regarding groundwater is too high content of iron and manganese, which can be reduced with the VYREDOX method. In some areas today there are severe problems with pollution by hydrocarbons and nitrate as well, and with modification of the VYREDOX treatment method it is used for hydrocarbon and nitrate treatment as well. The method to reduce the nitrate and nitrite is known as the NITREDOX method.

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