نتایج جستجو برای: urmia lake sediments

تعداد نتایج: 69393  

Groundwater resources are considered as a largest reservoir of available freshwater in the world. According to the importance and scarcity of this precious resource, studying the groundwater quality changes is very important. Declines in water level of Urmia lake has led to increase in the salinity of water in this lake. In this paper, water level reduction effects were studied on qualitative c...

Nature has always proven that it is able to overcome its problems. However, human manipulation has led to environmental degradations. The dryness of a thousand-year Urmia Lake (a brinewater lake in Iran) is an example of environmental degradation that happened due to successive droughts and construction of dams on the basin of this lake. This study examines methods for the revival of Urmia Lake...

2003
Amanda K. Parker M. B. Beck

Sediment from two Georgia Piedmont impoundments and soil from the Georgia Piedmont Bt horizon were incubated with an easily consumable organic carbon substrate in an anaerobic environment to observe iron reduction and phosphorus release. 97% of porewater iron in the Bt horizon soil, 96% of porewater iron in Lake Lanier sediments, and 93% of porewater iron in Lake Oglethorpe sediments was reduce...

Journal: :international journal of environmental research 2013
l. yang k. lei w. yan y. li

this study investigated the impact of internal nitrogen and phosphorus loading on water qualityof lake chaohu, china. results showed that the overall mean concentration of tn and tp in lake water was1.09±0.84 and 0.15±0.84 (sd) mg/l, respectively, indicating lake chaohu was highly eutrophic during thestudy period. mean benthic flux of nh4 +, no3 -, and po4 3- were 3.56±1.52 mg n/m2/d, -0.14±0.4...

Journal: :international journal of environmental research 0
l. yang river and coastal environment research center, chinese research academy of environmental sciences, beijing 100012, p. r. china k. lei river and coastal environment research center, chinese research academy of environmental sciences, beijing 100012, p. r. china w. yan institute of geographic sciences and natural resources research, chinese academy of sciencesÿ11a datun road, beijing, 100101, p.r. china a. mohseni-bandpei health faculty, shahid beheshti university of medical sciences, tehran, iran

this study investigated the impact of internal nitrogen and phosphorus loading on water qualityof lake chaohu, china. results showed that the overall mean concentration of tn and tp in lake water was1.09±0.84 and 0.15±0.84 (sd) mg/l, respectively, indicating lake chaohu was highly eutrophic during thestudy period. mean benthic flux of nh4 +, no3 -, and po4 3- were 3.56±1.52 mg n/m2/d, -0.14±0.4...

2002
O. G. Olila

Diel pH changes in lake waters resulting from high photosynthetic activity may regulate water-soluble P concentration (WSP) and P sorption by suspended sediments in shallow eutrophic lakes. Laboratory studies were conducted to determine the pH effect on P fractions and P sorption kinetics in oxidized sediment suspensions from two subtropical lakes (Lake Apopka and Lake Okeechobee, Florida). The...

2012
Yuika HYOBU Takaaki ITAI Daisuke HAYASE Michio KUMAGAI Shinsuke TANABE

Recently, hypoxia has become serious in Lake Biwa due to progressing of global warming. In this study, we determined Mn and As concentrations and their speciation in lake bottom water and sediments in June and December to elucidate their geochemical behaviors. Lake bottom water and sediment samples were collected from seven stations in the northern basin of Lake Biwa. In sediments, clear enrich...

Journal: :Anais da Academia Brasileira de Ciencias 2011
Adriana M C Horbe Hermann Behling Afonso C R Nogueira Russell Mapes

The sediments from the Coari lake, a "terra firme" lake sculpted into Plio-Pleistocene deposits, and the Acará lake, a flooding-type lake developed on Quaternary sediments in the floodplain of the mid-Solimões river, in the western Amazônia, Brazil, were studied to investigate the environmental condition of their developing. This study includes mineral composition, geochemistry, Pb isotope, pal...

Journal: :Environmental geochemistry and health 2004
H Wang C X Wang Z J Wang Z H Cao

The BCR (European Communities Bureau of Reference) three-step sequential extraction procedure was applied to fractionate heavy metals in the sediment of Taihu Lake. For the determination of total metal concentration of the sediments, sample digestion was achieved by using HF/H2O2/HNO3 (2/1/1) acid mixture in a microwave-irradiated closed vessel system. The concentrations of Cd, Ni, Cr, Zn, Cu a...

Journal: :Environmental monitoring and assessment 2014
Giulia Poma Claudio Roscioli Licia Guzzella

The reduction in the use of polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD) has opened the way for the introduction of novel brominated flame retardants (NBFRs) in place of the banned formulations. Important representatives of this group are decabromodiphenyl ethane (DBDPE), 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), hexabromobenzene (HBB), and pentabromoethylbenzen...

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