Photochemical Behavior of Microbial Extracellular Polymeric Substances in the Aquatic Environment

Author(s):  
Shaofeng Zhou ◽  
Zhiyang Liao ◽  
Beiping Zhang ◽  
Rui Hou ◽  
Yi Wang ◽  
...  
2014 ◽  
Vol 1015 ◽  
pp. 531-535
Author(s):  
Li Yun Ge ◽  
Shu Juan Li ◽  
Chang Rong Zhao ◽  
Huan Huan Deng

Extracellular polymeric substances (EPS) in marine algae-Platymonas subcordiformisaffected by enrofloxacin (ENR), the typical quinolone antibiotics released to the environment through different ways, was studied. A 3-dimension EEM (excitation –emission matrix) fluorescence spectroscopy was used to examine the interaction between EPS and ENR, and the fluorescent peaks A and B were detected, whose fluorescence intensity remarkably decreased with the increased ENR concentration. It was demonstrated that the interaction of EPS with ENR well fitted the modified Stern-Volmer. It was concluded that the presence of EPS in marine algae affected the transport and transform of antibiotics in aquatic environment.


2015 ◽  
Vol 12 (6) ◽  
pp. 627 ◽  
Author(s):  
Richard Kynaston Cross ◽  
Charles Tyler ◽  
Tamara S Galloway

Environmental context Engineered nanomaterials are increasingly being used and their release to the aquatic environment poses potential risk. We review the research on transformations of engineered nanomaterial in the aquatic sediment environments, and consider the implications of their release. The key factors defining the fate of engineered nanomaterials in aqueous and sediment systems are identified. Abstract Inorganic nanoparticles are at risk of release into the aquatic environment owing to their function, use and methods of disposal. Aquatic sediments are predicted to be a large potential sink for such engineered nanomaterial (ENM) emissions. On entering water bodies, ENMs undergo a range of transformations dependent on the physicochemical nature of the immediate environment, as they pass from the surface waters to sediments and into sediment-dwelling organisms. This review assesses the current state of research on transformations of metal-based ENMs in the aquatic environment, and considers the implications of these transformations for the fate and persistence of ENMs and their bioavailability to organisms within the benthos. We identify the following factors of key importance in the fate pathways of ENMs in aqueous systems: (1) extracellular polymeric substances, prevalent in many aquatic systems, create the potential for temporal fluxes of ENMs to the benthos, currently unaccounted for in predictive models. (2) Weak secondary deposition onto sediment grains may dominate sediment–ENM interactions for larger aggregates >500nm, potentially granting dynamic long-term mobility of ENMs within sediments. (3) Sulfurisation, aggregation and reduction in the presence of humic acid is likely to limit the presence of dissolved ions from soluble ENMs within sediments. (4) Key benthic species are identified based on their ecosystem functionality and potential for ENM exposure. On the basis of these findings, we recommend future research areas which will support prospective risk assessment by enhancing our knowledge of the transformations ENMs undergo and the likely effects these will have.


Author(s):  
Linda Sicko-Goad

Although the use of electron microscopy and its varied methodologies is not usually associated with ecological studies, the types of species specific information that can be generated by these techniques are often quite useful in predicting long-term ecosystem effects. The utility of these techniques is especially apparent when one considers both the size range of particles found in the aquatic environment and the complexity of the phytoplankton assemblages.The size range and character of organisms found in the aquatic environment are dependent upon a variety of physical parameters that include sampling depth, location, and time of year. In the winter months, all the Laurentian Great Lakes are uniformly mixed and homothermous in the range of 1.1 to 1.7°C. During this time phytoplankton productivity is quite low.


2020 ◽  
Vol 11 (10) ◽  
pp. 8547-8559
Author(s):  
Hongjing Zhao ◽  
Yu Wang ◽  
Mengyao Mu ◽  
Menghao Guo ◽  
Hongxian Yu ◽  
...  

Antibiotics are used worldwide to treat diseases in humans and other animals; most of them and their secondary metabolites are discharged into the aquatic environment, posing a serious threat to human health.


2020 ◽  
Author(s):  
N.A. Grekov ◽  
◽  
A.N. Grekov ◽  
E.N. Sychov ◽  
◽  
...  

2013 ◽  
Vol 25 (1-2) ◽  
pp. 136-148
Author(s):  
I. V. Gryb

The concept of an explosion in freshwater ecosystems as a result of the release of accumulated energy, accompanied by the destruction of the steady climax successions of hydrocenoses is presented. The typification of local explosions as well as methods for assessing their risk during the development of river basins are shown. The change in atmospheric circulation, impaired phases of the hydrological regime of rivers, increasing the average temperature of the planet, including in Polesie to 0,6 ºC, deforestation leads to concentration and release of huge amounts of unmanaged terrestrial energy, which manifests itself in the form of disasters and emergencies. Hydroecological explosion is formed as a result of multifactorial external influence (natural and anthropogenic) on the water body in a certain period of time. Moreover, its level at wastewater discharge depends on the mass of recycled impurities and behaved processing capacity of the reservoir, and the mass of dumped on biocides and the possibility of the water flow to their dilution and to the utilization of non-toxic concentrations. In all these cases the preservation of "centers of life" in the tributaries of the first order – local fish reproduction areas contributed to ecosystem recovery, and the entire ecosystem has evolved from equilibrium to non-equilibrium with further restructuring after the explosion and environmental transition to a new trophic level. It means that hydroecological explosion can be researched as the logical course of development of living matter in abiotic environmental conditions, ending abruptly with the formation of new species composition cenoses and new bio-productivity. The buffer capacity of the water environment is reduced due to re-development and anthropic transformation of geobiocenoses of river basins, which leads to a weakening of life resistance. This applies particularly to the southern industrial regions of Ukraine, located in the arid zone that is even more relevant in the context of increased average temperature due to the greenhouse effect, as well as to Polesie (Western, Central and Chernihiv), had been exposed to large-scale drainage of 60-80th years, which contributed to the degradation of peatlands and fitostroma. Imposing the western trace of emissions from the Chernobyl accident to these areas had created the conditions of prolonged hydroecological explosion in an intense process of aging water bodies, especially lakes, change in species composition of fish fauna and the occurrence of neoplasms at the organismal level. Under these conditions, for the existence of man and the environment the vitaukta should be strengthened, i.e. buffer resistance and capacitance the aquatic environment, bioefficiency on the one hand and balanced using the energy deposited - on the other. This will restore the functioning of ecosystems "channel-floodplain", "riverbed-lake", reducing the energy load on the aquatic environment. Hydroecological explosions of natural origin can not be considered a pathology – it is a jump process of natural selection of species of biota. Another thing, if they are of anthropogenic origin and if the magnitude of such an impact is on the power of geological factors. Hydroecological explosions can be regarded as a manifestation of environmental wars that consciously or unconsciously, human society is waging against themselves and their kind in the river basins, so prevention of entropy increase in the aquatic environment and the prevention of hydroecological explosions is a matter of human survival. While the man - is not the final link in the development of living matter, it can develop without him, as matter is eternal, and the forms of its existence are different.


2000 ◽  
Vol 71 (1) ◽  
pp. 29 ◽  
Author(s):  
Laura Bussotti ◽  
Maurizio D'Auria ◽  
Paolo Foggi ◽  
Giordano Lesma ◽  
Roberto Righini ◽  
...  

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