Molecular Monitoring of SRB Community Structure and Dynamics in Batch Experiments to Examine the Applicability of in situ Precipitation of Heavy Metals for Groundwater Remediation (15 pp)

2004 ◽  
Vol 5 (3) ◽  
pp. 149-163 ◽  
Author(s):  
Joke Geets ◽  
Brigitte Borremans ◽  
Jaco Vangronsveld ◽  
Ludo Diels ◽  
Daniël van der Lelie
NANO ◽  
2008 ◽  
Vol 03 (04) ◽  
pp. 287-289 ◽  
Author(s):  
STEPANKA KLIMKOVA ◽  
MIROSLAV CERNIK ◽  
LENKA LACINOVA ◽  
JAROSLAV NOSEK

It is known that the reductive effects of zero-valent iron ( Fe 0) and the sorptive capability of iron and its oxides can be used for both the dehalogenation of chlorinated hydrocarbons (CHC), especially of chlorinated ethenes (PCE → TCE → DCE → VC → ethene, ethane), and the removing of heavy metals from groundwater by turning them into a less-soluble form through changes of their oxidation state, or by adsorption. These consequences are being exploited in the construction of iron filling permeable reactive barriers for a longer time.1 The advantages of nanoscale zero-valent iron ( nanoFe 0) over the macroscopic one consist not only in the better reactivity implicit in their greater specific surface area but also in their mobility in rock environment.2,3 Numerous laboratory experiments, especially the batch-agitated experiments, with samples from seven various contaminated localities in Europe have been carried out with the aim to discover the measurement of the reductive effect of the nanoFe 0 on selected contaminants. It was found that the nanoFe 0 can be reliably usable as a reductive reactant for in-situ chemical decontamination of sites polluted by chlorinated ethenes (CEs), or hexa-valent chromium ( Cr VI ). The rate of reductive reaction and the optimal concentrations for the real remediation action were determined. On the basis of these laboratory experiments, the methods for pilot application of nanoFe 0 have been specified. Subsequently the pilot experiments were accomplished in surveyed localities.


Author(s):  
Chin-Yuan Huang ◽  
Pei-Cheng Cheng ◽  
Jih-Hsing Chang ◽  
Yu-Chih Wan ◽  
Xiang-Min Hong ◽  
...  

Heavy metals contamination in groundwater often occurs in various industrial processes. Stud-ies have confirmed that polysulfide could reduce hexavalent chromium to trivalent chromium, achieving the effect of in-situ stabilization. For other heavy metals contamination in groundwa-ter, whether polysulfide also had a stabilizing ability to achieve in-situ remediation. This re-search focused on heavy metals except for chromium that often contaminated in groundwater, including lead, nickel, zinc, copper, and cadmium to explore the feasibility of using calcium polysulfide (CaSx) as an in-situ stabilization technology for these heavy metals contamination groundwater. Results showed that CaSx had a great removal efficiency for heavy metals lead, nickel, zinc, copper, and cadmium. However, for nickel, zinc, copper and cadmium, when CaSx was added excessively, complexes would be formed, causing the result of re-dissolve and this would also reduce the removal efficiency. Since it is difficult to accurately control the dosage of agents for in-situ groundwater remediation, the concentration of re-dissolved nickel, zinc, cop-per, and cadmium may not be able to meet the groundwater control standards. CaSx had high lead removal efficiency, and it would not cause re-dissolution due to excessive CaSx dosing. CaSx can be used as an in-situ stabilization technique for lead contaminated groundwater.


Toxics ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 190 ◽  
Author(s):  
Roddy Jara-Yáñez ◽  
Andrés Meynard ◽  
Gladys Acosta ◽  
Nicolás Latorre-Padilla ◽  
Carolina Oyarzo-Miranda ◽  
...  

The study of pollution effects in the marine environment has become important in recent decades, and the exposure to simultaneous pollutants has become especially relevant. Indeed, the study of key organisms, such as ecosystem engineers, can show a broader view of the effects of pollutants. In this context, we evaluate in situ the effects of a short (7-day) pollution pulse of combined solutions of heavy metals and polycyclic aromatic hydrocarbons (PAHs) (Cu + PAHs, Cd + PAHs, Cu + Cd, and Cu + Cd + PAHs) on the development and morphological features of Macrocystis pyrifera sporophytes over a period of 90 days. Additionally, we determined the effects on the community structure associated with this kelp. This study evidenced a smaller number of blades and a decreased size of blades and holdfasts, as well as the death of individuals exposed to a secondary mix of metals (Cu + Cd) and a tertiary mix of pollutants (Cu + Cd + PAHs). Regarding the effects on the accompanying fauna, low richness and diversity were registered. M. pyrifera grazers, according to the mixture of pollutants, were either absent or diminished. These results show that the pulse of contamination in the early stages of M. pyrifera negatively affects its development and morphometry, as well as its role as an ecosystem engineer, due to a negative alteration in the species composition.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Wenjun Li ◽  
Xiaofang Li

Abstract Background Mine tailings are hostile environment. It has been well documented that several microbes can inhabit such environment, and metagenomic reconstruction has successfully pinpointed their activities and community structure in acidic tailings environments. We still know little about the microbial metabolic capacities of alkaline sulphidic environment where microbial processes are critically important for the revegetation. Microbial communities therein may not only provide soil functions, but also ameliorate the environment stresses for plants’ survival. Results In this study, we detected a considerable amount of viable bacterial and archaeal cells using fluorescent in situ hybridization in alkaline sulphidic tailings from Mt Isa, Queensland. By taking advantage of high-throughput sequencing and up-to-date metagenomic binning technology, we reconstructed the microbial community structure and potential coupled iron and nitrogen metabolism pathways in the tailings. Assembly of 10 metagenome-assembled genomes (MAGs), with 5 nearly complete, was achieved. From this, detailed insights into the community metabolic capabilities was derived. Dominant microbial species were seen to possess powerful resistance systems for osmotic, metal and oxidative stresses. Additionally, these community members had metabolic capabilities for sulphide oxidation, for causing increased salinity and metal release, and for leading to N depletion. Conclusions Here our results show that a considerable amount of microbial cells inhabit the mine tailings, who possess a variety of genes for stress response. Metabolic reconstruction infers that the microbial consortia may actively accelerate the sulphide weathering and N depletion therein.


1990 ◽  
Vol 5 ◽  
pp. 13-30 ◽  
Author(s):  
D. A. Springer ◽  
A. I. Miller

The way we view species distribution patterns, particularly at the level commonly referred to as the “community”, has changed over the past 70 years in biology and, subsequently, in paleontology. Because the degree to which species associations can be interpreted as ecological and evolutionary units depends ultimately on recognition and interpretation of faunal spatial variability, we need to understand the nature of this variability at all levels of resolution before we can adequately address questions of “community” structure and dynamics. While it is possible to recognize spatial variability at several levels, from the distributions of individuals within a species to the overall pattern created by the global biota, we must ask whether these patterns really comprise a hierarchy with natural discontinuities (Fig. 1), or whether it is more realistic to view them as a continuous variability spectrum.


2000 ◽  
Vol 42 (7-8) ◽  
pp. 335-343 ◽  
Author(s):  
S. Shiba ◽  
S. Hino ◽  
Y. Hirata ◽  
T. Seno

The operational variables of electrokinetic remediation have not been cleared yet, because this method is relatively new and is an innovative technique in the aquifer remediation. In order to investigate the operational variables of the electrokinetic remediation, a mathematical model has been constructed based on the physico chemical mass transport process of heavy metals in pore water of contaminated aquifer. The transport of the heavy metals is driven not only by the hydraulic flow due to the injection of the purge water but also by the electromigration due to the application of the electric potential gradient. The electric potential between anode and cathode is the important operational variable for the electrokinetic remediation. From the numerical simulations with use of this model it is confirmed that the remediation starts from the up stream anode and gradually the heavy metal is transported to the down stream cathode and drawn out through the purge water.


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