Microbial Mercury Methylation in Aquatic Environments: A Critical Review of Published Field and Laboratory Studies

2018 ◽  
Vol 53 (1) ◽  
pp. 4-19 ◽  
Author(s):  
Olof Regnell ◽  
Carl. J. Watras
Keyword(s):  
Critical Review ◽  
Mercury Methylation ◽  
Aquatic Environments ◽  
Laboratory Studies

A critical review of control and removal strategies for microplastics from aquatic environments

2021 ◽  
Vol 9 (4) ◽  
pp. 105463
Author(s):  
Yingshuang Zhang ◽  
Hongru Jiang ◽  
Kai Bian ◽  
Hui Wang ◽  
Chongqing Wang
Keyword(s):  
Critical Review ◽  
Aquatic Environments

Recovery of 13CO2 and 14CO2 in Human Bicarbonate Studies: A Critical Review with Original Data

1996 ◽  
Vol 91 (6) ◽  
pp. 665-677 ◽  
Author(s):  
D. P. C. Leijssen ◽  
M. Elia
Keyword(s):  
Steady State ◽  
Critical Review ◽  
Original Data ◽  
Laboratory Studies ◽  
Methodological Issues ◽  
Multiple Sources ◽  
Study Protocols ◽  
Wide Variability ◽  
Scintillation Fluid ◽  
Rest And Exercise

1. In order to establish biological and/or methodological explanations for the wide variability in recovery (50–100%) of labelled CO2 after administration of [13C]bicarbonate or [14C]bicarbonate, 34 human bicarbonate studies involving 480 subjects were analysed, and potential methodological issues were investigated in the laboratory. 2. Overall, continuous infusion studies reported a higher recovery than bolus studies (84 ± 11% versus 69 ± 12%; P < 0.001). No significant differences in recovery were found between 14C and 13C studies, children and adults, obese and lean subjects, or rest and exercise (steady state). Higher recoveries were found during feeding than during fasting (84 ± 8% versus 74 ± 7%; P < 0.001). Different methods used to analyse the results (0–10%) and different study protocols, which include differences in the duration of infusions and background drift in 13C enrichment (0–10%), contribute to the variability. 3. The laboratory studies suggest multiple sources of potential error, including loss of CO2 from the scintillation fluid (up to >30%, but only in 14C studies in which the scintillation fluid is not alkalized), diffusion of CO2 through syringes and tubing (0 to > 10%), non-linearity of CO2 analysers (up to 8%), inaccuracies in the measurement of bicarbonate concentrations (13C studies) or the strength of CO2-trapping agents (14C studies; 0–8%). 4. It is concluded that much of the variability in the recovery of labelled bicarbonate is likely to be attributable to methodological differences, and that attention to these will ensure better interpretation of metabolic studies that involve oxidation of carbon-labelled substrates.

Mercury methylation and its accumulation in rice and paddy soil in degraded lands: A critical review

2021 ◽  
pp. 101638
Author(s):  
Shehla Amin ◽  
Sardar Khan ◽  
Tasneem Sarwar ◽  
Javed Nawab ◽  
Muhammad Amjad Khan
Keyword(s):  
Paddy Soil ◽  
Critical Review ◽  
Mercury Methylation ◽  
Degraded Lands

scholarly journals Evidence of Mercury Methylation and Demethylation by the Estuarine Microbial Communities Obtained in Stable Hg Isotope Studies

2018 ◽  
Vol 15 (10) ◽  
pp. 2141 ◽  
Author(s):  
Neusa Figueiredo ◽  
Maria Serralheiro ◽  
João Canário ◽  
Aida Duarte ◽  
Holger Hintelmann ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Critical Factor ◽  
High Rate ◽  
Mercury Removal ◽  
Tagus Estuary ◽  
Simultaneous Occurrence ◽  
Mercury Methylation ◽  
Aquatic Environments ◽  
Isotope Studies ◽  
Microbial Methylation

Microbial activity is a critical factor controlling methylmercury formation in aquatic environments. Microbial communities were isolated from sediments of two highly mercury-polluted areas of the Tagus Estuary (Barreiro and Cala do Norte) and differentiated according to their dependence on oxygen into three groups: aerobic, anaerobic, and sulphate-reducing microbial communities. Their potential to methylate mercury and demethylate methylmercury was evaluated through incubation with isotope-enriched Hg species (199HgCl and CH3201HgCl). The results showed that the isolated microbial communities are actively involved in methylation and demethylation processes. The production of CH3199Hg was positively correlated with sulphate-reducing microbial communities, methylating up to 0.07% of the added 199Hg within 48 h of incubation. A high rate of CH3201Hg degradation was observed and >20% of CH3201Hg was transformed. Mercury removal of inorganic forms was also observed. The results prove the simultaneous occurrence of microbial methylation and demethylation processes and indicate that microorganisms are mainly responsible for methylmercury formation and accumulation in the polluted Tagus Estuary.

Laccase-Mediated Treatment of Pharmaceutical Wastes

2018 ◽  
pp. 213-252 ◽  
Author(s):  
Hamid Forootanfar ◽  
Shokouh Arjmand ◽  
Mina Behzadi ◽  
Mohammad Ali Faramarzi
Keyword(s):  
Nineteenth Century ◽  
Literature Review ◽  
Molecular Mechanism ◽  
Mechanism Of Action ◽  
Critical Review ◽  
Pivotal Role ◽  
Aquatic Environments ◽  
Review Of The Literature ◽  
Molecular Mechanism Of Action

Laccases are versatile multi-copper enzymes belonging to the superfamily of oxidase enzymes, which have been known since the nineteenth century. Recent discoveries have refined investigators' views of the potential of laccase as a magic tool for remarkable biotechnological purposes. A literature review of the capabilities of laccases, their assorted substrates, and their molecular mechanism of action now indicates the emergence of a new direction for laccase application as part of an arsenal in the fight against the contamination of water supplies by a number of frequently prescribed medications. This chapter provides a critical review of the literature and reveals the pivotal role of laccases in the elimination and detoxification of pharmaceutical contaminants in aquatic environments and wastewaters.

From Sampling to Analysis: A Critical Review of Techniques Used in the Detection of Micro- and Nanoplastics in Aquatic Environments

2021 ◽  
Vol 1 (4) ◽  
pp. 748-764
Author(s):  
Javier Delgado-Gallardo ◽  
Geraint L. Sullivan ◽  
Peter Esteban ◽  
Ziyan Wang ◽  
Ozgur Arar ◽  
...  
Keyword(s):  
Critical Review ◽  
Aquatic Environments
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