Microbial Bioreactor Systems for Dehalogenation of Organic Pollutants

Author(s):  
Raghunath Satpathy

Halogenated organic compounds having many beneficial applications, both in industries and agriculture sectors. Basically, the uses are as pesticides, solvents, surfactants, and plastics. However, their large, widespread uses throughout the world have resulted the negative impact on the environment. Considering their treatment process are widely accepted by using the bioreactor systems. The large variety of microorganisms present in the bioreactor and their interaction is the key to the effective treatment and removal of these compounds. Usually the microbes produce the enzymes known as dehalogenase to remove the halogen form the compounds to make it non-toxic. Many of the different steps and about the microbial groups in degradation process of halogenated compounds are well understood, but more details concerning the microbial community are yet to be discovered. This chapter describes about the different dehalogenation systems available in microbes and their ultimate application in different bioreactor systems for the degradation analysis of several harmful halogenated compounds.

Author(s):  
Dennis G. Peters ◽  
Caitlyn M. McGuire ◽  
Erick M. Pasciak ◽  
Angela A. Peverly ◽  
Lauren M. Strawsine ◽  
...  

<p>This review summarizes our own research, published since 2004, dealing with electrochemical reduction of halogenated organic compounds that are environmental pollutants. Included are sections surveying the direct and mediated reduction of the following species: (a) chlorofluorocarbons; (b) pesticides, fungicides, and bactericides; (c) flame retardants; and (d) disinfection by-products arising from the chlorination of water. To provide the reader with a perspective of these topics beyond our own work, a total of 238 literature citations, pertaining to studies conducted in numerous laboratories around the world, appears at the end of this review.</p>


2014 ◽  
Vol 925 ◽  
pp. 689-693 ◽  
Author(s):  
Nadia Riaz ◽  
Bustam-Khalil Mohamad Azmi ◽  
Azmi Mohd Shariff

One of the most pervasive problems affecting people throughout the world is inadequate access to clean water and sanitation. Problems with water are expected to grow worse in the coming decades, with water scarcity occurring globally. Many recent studies have been reported on the photodegradation of the organic compounds in industrial wastewater in the presence of TiO2 semiconductor as photocatalyst. Heterogeneous photocatalysts using iron as a dopant metal, so far, have been reported for various environmental applications. This paper highlights the recent advances and applications of Fe-TiO2 photocatalysis for the degradation/photodegradation of various pollutants, alkanolamines and other organic pollutants like phenols and dyes.


Fermentation ◽  
2020 ◽  
Vol 6 (3) ◽  
pp. 85
Author(s):  
Birthe V Nielsen ◽  
Supattra Maneein ◽  
Md Mahmud Al Farid ◽  
John J Milledge

The urgent need to replace fossil fuels has seen macroalgae advancing as a potential feedstock for anaerobic digestion. The natural methane productivity (dry weight per hectare) of seaweeds is greater than in many terrestrial plant systems. As part of their defence systems, seaweeds, unlike terrestrial plants, produce a range of halogenated secondary metabolites, especially chlorinated and brominated compounds. Some orders of brown seaweeds also accumulate iodine, up to 1.2% of their dry weight. Fluorine remains rather unusual within the chemical structure. Halogenated hydrocarbons have moderate to high toxicities. In addition, halogenated organic compounds constitute a large group of environmental chemicals due to their extensive use in industry and agriculture. In recent years, concerns over the environmental fate and release of these halogenated organic compounds have resulted in research into their biodegradation and the evidence emerging shows that many of these compounds are more easily degraded under strictly anaerobic conditions compared to aerobic biodegradation. Biosorption via seaweed has become an alternative to the existing technologies in removing these pollutants. Halogenated compounds are known inhibitors of methane production from ruminants and humanmade anaerobic digesters. The focus of this paper is reviewing the available information on the effects of halogenated organic compounds on anaerobic digestion.


2020 ◽  
pp. 276-289
Author(s):  
Mobina Fathi ◽  
Kimia Vakili ◽  
Niloofar Deravi

Around the end of December 2019, a new beta-coronavirus from Wuhan City, Hubei Province, China began to spread rapidly. The new virus, called SARS-CoV-2, which could be transmitted through respiratory droplets, had a range of mild to severe symptoms, from simple cold in some cases to death in others. The disease caused by SARS-CoV-2 was named COVID-19 by WHO and has so far killed more people than SARS and MERS. Following the widespread global outbreak of COVID-19, with more than 132758 confirmed cases and 4955 deaths worldwide, the World Health Organization declared COVID-19 a pandemic disease in January 2020. Earlier studies on viral pneumonia epidemics has shown that pregnant women are at greater risk than others. During pregnancy, the pregnant woman is more prone to infectious diseases. Research on both SARS-CoV and MERS-CoV, which are pathologically similar to SARS-CoV-2, has shown that being infected with these viruses during pregnancy increases the risk of maternal death, stillbirth, intrauterine growth retardation and, preterm delivery. With the exponential increase in cases of COVID-19 throughout the world, there is a need to understand the effects of SARS-CoV-2 on the health of pregnant women, through extrapolation of earlier studies that have been conducted on pregnant women infected with SARS-CoV, and MERS-CoV. There is an urgent need to understand the chance of vertical transmission of SARS-CoV-2 from mother to fetus and the possibility of the virus crossing the placental barrier. Additionally, since some viral diseases and antiviral drugs may have a negative impact on the mother and fetus, in which case, pregnant women need special attention for the prevention, diagnosis, and treatment of COVID-19.


2019 ◽  
Vol 2 (4) ◽  
pp. 151
Author(s):  
Bashir Hadi Abdul Razak

The Arab-Israeli conflict is among the longest and most complex conflicts in the world today, a conflict that transcends borders or a difference of influence. It is a struggle for existence in every sense. Since the establishment of Israel in 1948, one of the regional forces whose political movement is determined by the Arab world has become the result of the internal and external factors and changes that affect it. This entity is hostile to the Arabs, Which would have a negative impact on the regional strategic situation.


2020 ◽  
Vol 27 (14) ◽  
pp. 2335-2360 ◽  
Author(s):  
Chao Li ◽  
Dayong Shi

: Marine organisms are abundant sources of bioactive natural products. Among metabolites produced by sponges and their associated microbial communities, halogenated natural compounds accounted for an important part due to their potent biological activities. The present review updates and compiles a total of 258 halogenated organic compounds isolated in the past three decades, especially brominated derivatives derived from 31 genera of marine sponges. These compounds can be classified as the following classes: brominated polyunsaturated lipids, nitrogen compounds, brominated tyrosine derivatives and other halogenated compounds. These substances were listed together with their source organisms, structures and bioactivities. For this purpose, 84 references were consulted.


Atmosphere ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 94
Author(s):  
Esther Borrás ◽  
Luis Antonio Tortajada-Genaro ◽  
Francisco Sanz ◽  
Amalia Muñoz

The chemical characterization of aerosols, especially fine organic fraction, is a relevant atmospheric challenge because their composition highly depends on localization. Herein, we studied the concentration of multi-oxygenated organic compounds in the western Mediterranean area, focusing on sources and the effect of air patterns. The organic aerosol fraction ranged 3–22% of the total organic mass in particulate matter (PM)2.5. Seventy multi-oxygenated organic pollutants were identified by gas chromatography–mass spectrometry, including n-alkanones, n-alcohols, anhydrosugars, monocarboxylic acids, dicarboxylic acids, and keto-derivatives. The highest concentrations were found for carboxylic acids, such as linoleic acid, tetradecanoic acid and, palmitic acid. Biomarkers for vegetation sources, such as levoglucosan and some fatty acids were detected at most locations. In addition, carboxylic acids from anthropogenic sources—mainly traffic and cooking—have been identified. The results indicate that the organic PM fraction in this region is formed mainly from biogenic pollutants, emitted directly by vegetation, and from the degradation products of anthropogenic and biogenic volatile organic pollutants. Moreover, the chemical profile suggested that this area is interesting for aerosol studies because several processes such as local costal breezes, industrial emissions, and desert intrusions affect fine PM composition.


Author(s):  
Marina Yiasemidou

AbstractThe COVID-19 pandemic and infection control measures had an unavoidable impact on surgical services. During the first wave of the pandemic, elective surgery, endoscopy, and ‘face-to-face’ clinics were discontinued after recommendations from professional bodies. In addition, training courses, examinations, conferences, and training rotations were postponed or cancelled. Inadvertently, infection control and prevention measures, both within and outside hospitals, have caused a significant negative impact on training. At the same time, they have given space to new technologies, like telemedicine and platforms for webinars, to blossom. While the recovery phase is well underway in some parts of the world, most surgical services are not operating at full capacity. Unfortunately, some countries are still battling a second or third wave of the pandemic with severely negative consequences on surgical services. Several studies have looked into the impact of COVID-19 on surgical training. Here, an objective overview of studies from different parts of the world is presented. Also, evidence-based solutions are suggested for future surgical training interventions.


2021 ◽  
Vol 9 (2) ◽  
pp. 211
Author(s):  
Jie Gao ◽  
Miao Liu ◽  
Sixue Shi ◽  
Ying Liu ◽  
Yu Duan ◽  
...  

In this study, we analyzed microbial community composition and the functional capacities of degraded sites and restored/natural sites in two typical wetlands of Northeast China—the Phragmites marsh and the Carex marsh, respectively. The degradation of these wetlands, caused by grazing or land drainage for irrigation, alters microbial community components and functional structures, in addition to changing the aboveground vegetation and soil geochemical properties. Bacterial and fungal diversity at the degraded sites were significantly lower than those at restored/natural sites, indicating that soil microbial groups were sensitive to disturbances in wetland ecosystems. Further, a combined analysis using high-throughput sequencing and GeoChip arrays showed that the abundance of carbon fixation and degradation, and ~95% genes involved in nitrogen cycling were increased in abundance at grazed Phragmites sites, likely due to the stimulating impact of urine and dung deposition. In contrast, the abundance of genes involved in methane cycling was significantly increased in restored wetlands. Particularly, we found that microbial composition and activity gradually shifts according to the hierarchical marsh sites. Altogether, this study demonstrated that microbial communities as a whole could respond to wetland changes and revealed the functional potential of microbes in regulating biogeochemical cycles.


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