Effects of antibiotics and heavy metals on denitrification in shallow eutrophic lakes

The risk of heavy metals to aquatic ecosystems was paid much attention in recent years, however, the knowledge on effects of heavy metals on dissolved organic matter (DOM) released byMicrocystiswas quite poor, especially in eutrophic lakes.

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Valuable ingredients and feed toxicity evaluation of Microcystis aeruginosa acidolysis product in mice

Experimental Biology and Medicine ◽

10.1177/1535370214563894 ◽

2015 ◽

Vol 240 (10) ◽

pp. 1333-1339 ◽

Cited By ~ 2

Author(s):

Shiqun Han ◽

Qing Zhou ◽

Yudi Xu ◽

Floris Vanogtrop ◽

Qijin Guo ◽

...

Keyword(s):

Heavy Metals ◽

Amino Acid ◽

Hydrochloric Acid ◽

Microcystis Aeruginosa ◽

Micronucleus Test ◽

Lethal Dose ◽

Total Amino Acid ◽

Algal Toxins ◽

Eutrophic Lakes ◽

Amino Acid Requirements

This research studied the extraction from Microcystis aeruginosa using hydrochloric acid method as a potentially valuable protein resource from eutrophic lakes. Amino acid composition, residual algal toxins, and heavy metals of the acidolysis product were studied. After 18 h of hydrochloric acid treatment, the product of M. aeruginosa contained 17 amino acids, 51.34% of total amino acid requirements, and 30.25% of the livestock and poultry essential amino acid (Eaa). The residual microcystin-LR (MC-LR) was 0.94 µg kg−1, which was less than WHO drinking water limit of microcystins. The removal ratio of microcystins was higher than 99.99% during the process of hydrolysis. The concentration of heavy metals of the product was in compliance with feed standards. Furthermore, using Horn’s method, Mouse Micronucleus Test and Sperm Shape Abnormality Test were conducted to study the forage safety of the product. Half lethal dose (LD50) of acidolysis product in mice was >9.09 g kg−1 body weight, actually belonging to non-toxic grade. Every dose treatment did not significantly increase activities of alkaline phosphatase (ALP), lactate dehydrogenase (LDH), and γ-glutamyltransferase (γ-GT). The results of both micronucleus test and sperm shape abnormality test were negative, which suggested the product with no mutagenicity and sperm malformation effects. This study indicated that the acidolysis product of M. aeruginosa was safe to be used as a feed ingredient.

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Geochemical composition of sapropel in lakes: reflections of paleoenvironmental conditions and anthropogenic influence

10.21203/rs.2.23637/v1 ◽

2020 ◽

Author(s):

Jonas Satkūnas ◽

Vaidotas Valskys ◽

Gytautas Ignatavičius ◽

Alma Grigienė

Keyword(s):

Heavy Metals ◽

Environmental Changes ◽

Human Impacts ◽

Chemical Elements ◽

Wide Spectrum ◽

Anthropogenic Activity ◽

Chemical Compositions ◽

Eutrophic Lakes ◽

Geochemical Composition ◽

The Impact

Abstract Geochemical and lithological parameters of sapropel in lakes, combined with pollen data and radiocarbon 14C datings, contain a wide spectrum of environmental information. This includes records of fluctuations of water level and changes of conditions of sedimentation, accumulation of organic matter and chemical elements due to climate change, human impacts and other environmental changes. Four lakes with different trophic states and anthropogenic pressures were chosen for this study in Lithuania. Lake Balsys has a mesotrophic state while Lakes Didžiulis, Salotė and Gineitiškės have eutrophic states. X-ray fluorescence spectrometry was used to analyse concentrations of chemical elements, loss-on-ignition to determine organic, mineral and carbonate matter, pollen analysis and radiocarbon dating were applied for determination of paleoenvironmental conditions and age of sediments. Results of this study demonstrated rather different chemical compositions of sapropels in these lakes. Human impacts are evident in the upper layers of sapropel in all lakes, however very specific and complex geochemical composition was determined in deeper layers of sapropel in the different lakes. Higher concentrations of elements like Cr and Zn are expected in deeper layers of sapropel and are attributed to lithogenic association of trace elements. Pb and Cu were detected in upper layers of sapropel which indicates the impact of anthropogenic activity. Sapropel of eutrophic lakes (Salotė and Gineitiškės) is enriched by high concentrations of heavy metals (galbūt naudoti tiesiog chemical elements?) (Pb, Cr, Cu, Zn). Their main source was multidimensional anthropogenic pollution leading to a biogenic-anthropogenic association of elements. Sapropel with low concentrations of heavy metals exhibits a different inter-association matrix because most of the elements tend to form lithogenic-clastogenic associations.

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Bioaccumulation of Heavy Metals by Submerged Macrophytes: Looking for Hyperaccumulators in Eutrophic Lakes

Environmental Science & Technology ◽

10.1021/es303923w ◽

2013 ◽

Vol 47 (9) ◽

pp. 4695-4703 ◽

Cited By ~ 71

Author(s):

Wei Xing ◽

Haoping Wu ◽

Beibei Hao ◽

Wenmin Huang ◽

Guihua Liu

Keyword(s):

Heavy Metals ◽

Submerged Macrophytes ◽

Eutrophic Lakes

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Speciation of Heavy Metals in the Sediments from Different Eutrophic Lakes of China

Procedia Engineering ◽

10.1016/j.proeng.2011.11.050 ◽

2011 ◽

Vol 18 ◽

pp. 318-323 ◽

Cited By ~ 11

Author(s):

LU Cheng-xiu ◽

Cheng Jie-min

Keyword(s):

Heavy Metals ◽

Eutrophic Lakes

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Sampling and analysis of the air-water interface with SEM and EDS of microlayers

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100157000 ◽

1989 ◽

Vol 47 ◽

pp. 1004-1005

Author(s):

Randall W. Smith ◽

John Dash

Keyword(s):

Heavy Metals ◽

Surface Microlayer ◽

Surface Films ◽

Water Interface ◽

Physical Processes ◽

Infrared Spectroscopic Analysis ◽

Eds Analysis ◽

Air Water Interface ◽

Significant Area ◽

Bulk Chemical

The structure of the air-water interface forms a boundary layer that involves biological ,chemical geological and physical processes in its formation. Freshwater and sea surface microlayers form at the air-water interface and include a diverse assemblage of organic matter, detritus, microorganisms, plankton and heavy metals. The sampling of microlayers and the examination of components is presently a significant area of study because of the input of anthropogenic materials and their accumulation at the air-water interface. The neustonic organisms present in this environment may be sensitive to the toxic components of these inputs. Hardy reports that over 20 different methods have been developed for sampling of microlayers, primarily for bulk chemical analysis. We report here the examination of microlayer films for the documentation of structure and composition.Baier and Gucinski reported the use of Langmuir-Blogett films obtained on germanium prisms for infrared spectroscopic analysis (IR-ATR) of components. The sampling of microlayers has been done by collecting fi1ms on glass plates and teflon drums, We found that microlayers could be collected on 11 mm glass cover slips by pulling a Langmuir-Blogett film from a surface microlayer. Comparative collections were made on methylcel1ulose filter pads. The films could be air-dried or preserved in Lugol's Iodine Several slicks or surface films were sampled in September, 1987 in Chesapeake Bay, Maryland and in August, 1988 in Sequim Bay, Washington, For glass coverslips the films were air-dried, mounted on SEM pegs, ringed with colloidal silver, and sputter coated with Au-Pd, The Langmuir-Blogett film technique maintained the structure of the microlayer intact for examination, SEM observation and EDS analysis were then used to determine organisms and relative concentrations of heavy metals, using a Link AN 10000 EDS system with an ISI SS40 SEM unit. Typical heavy microlayer films are shown in Figure 3.

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