Sequestering Groundwater Contaminants via Emerging Nanocomposite Adsorbents

Author(s):  
Mitil M. Koli ◽  
Kritika Jashrapuria ◽  
Anima Johari ◽  
Swatantra P. Singh
1997 ◽  
Vol 36 (6-7) ◽  
pp. 125-132 ◽  
Author(s):  
Toshiya Komatsu ◽  
Jun Shinmyo ◽  
Kiyoshi Momonoi

Tetrachloroethylene (PCE) is one of the most common groundwater contaminants in Japan. PCE can be completely dechlorinated to ethylene (ETY) and ethane (ETA) by anaerobic microorganisms in the presence of a suitable electron donor. This study was conducted to examine the feasibility of using an anaerobic filter for the degradation of PCE in a bioremediation process. Laboratory-scale anaerobic filters were operated at 25°C using ethanol as the electron donor. Rapid start-up of the reactors was achieved by using anaerobic completely PCE-dechlorinating enrichment cultures as the inoculum. During the continuous operating periods, low concentrations (2.8 mg/L) of PCE were almost completely dechlorinated to ETY and ETA at hydraulic retention times of 49-15 hours with 100 mgCOD/L of ethanol. PCE concentrations as high as 80 mg/L was dechlorinated to ETY with a relatively low supply (200 mgCOD/L) of ethanol. Results of this study suggest that the anaerobic filter system is a feasible bioremediation process for the cleanup of groundwater which is contaminated by chlorinated ethylenes.


1990 ◽  
Vol 64 (4) ◽  
pp. 320-328 ◽  
Author(s):  
Gin C. Hsieh ◽  
Robert D. R. Parker ◽  
Raghubir P. Sharma ◽  
Brian J. Hughes

2021 ◽  
Vol 27 (12) ◽  
pp. 23-32
Author(s):  
Hayat Azawi ◽  
May Samir Saleh

Kriging, a geostatistical technique, has been used for many years to evaluate groundwater quality. The best estimation data for unsampled points were determined by using this method depending on measured variables for an area. The groundwater contaminants assessment worldwide was found through many kriging methods. The present paper shows a review of the most known methods of kriging that were used in estimating and mapping the groundwater quality. Indicator kriging, simple kriging, cokriging, ordinary kriging, disjunctive kriging and lognormal kriging are the most used techniques. In addition, the concept of the disjunctive kriging method was explained in this work to be easily understood.


2019 ◽  
Vol 96 (10) ◽  
pp. 946-949 ◽  
Author(s):  
Mikhail S. Dementiev ◽  
D. M. Dementieva

In most regions of the central part of the North Caucasus, there is a persistent increase in the prevalence rate of congenital malformations of the child population and the development of other health problems. It is probable due to the fact that unlike many other regions of Russia the upper reaches of the Kuban water are contaminated by metals with a significant excess of MPCrx due to their entry from rock depths. The highest excess of manganese, copper and iron was observed. For other metals there are specific for individual waters deviations upward or downward. To date, the water in large quantities for the irrigation network is transmitted in steppe regions, feasting upon the path of additional quantities of natural contaminants, and mainly anthropogenic origin. The massive use of irrigated agriculture, the saturation of groundwater contaminants is the basis for their accumulation in the agricultural products. Thus, after drinking it is the second a local source of metals in the human body. The problem for detection of correlative relationships between pollution and human health in this case is the lack of such a target as the total MPC of pollutants in the human body, balancing entry-selection for different age, gender and other characteristics of human differences.


2004 ◽  
Vol 82 (10) ◽  
pp. 1495-1506 ◽  
Author(s):  
M S Odziemkowski ◽  
R P Simpraga

The distribution of oxides on commercial iron materials used for remediation of organic groundwater contaminants was studied using confocal Raman microspectroscopy. Raman microprobe mapping experiments revealed that commercial iron materials used for the construction of permeable reactive barriers are covered with an oxide film consisting of an inner film of magnetite Fe3O4 and an outer film of Fe2O3. The calculated probability of the charge transfer process (i.e., electron tunnelling probability) at commercial Fe | Fe2O3 (semiconductor) | solution interfaces approaches zero, indicating that "as received" commercial iron materials should not be reactive towards both organic contaminants and water. The combination of OCP (corrosion potential) – time measurements with in situ Raman spectroscopy demonstrated that the breakdown of the protective Fe2O3 oxide film followed by autoreduction of Fe2O3 is a requirement for the commercial materials to be chemically active towards both water and organic contaminants. Hydrogen evolution reactions on metals and oxide-covered iron were also investigated. In particular, spectroscopic evidence for adsorption of atomic hydrogen on polycrystalline Pt is presented. The possibility of adsorption of H on magnetite-covered iron was considered using thermodynamic calculations after Marcus and Protopopoff. The evolution of hydrogen on commercial iron materials is described. It is suggested that the separation of the anodic and cathodic sites because of opening of pores in the bulk metallic Fe and the involvement of spill-over hydrogen may play a crucial role in the catalytic hydrogenation of groundwater contaminants.Key words: Raman microprobe confocal spectroscopy, iron oxides, hydrogen evolution, remediation of organic groundwater contaminants.


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