scholarly journals Comparison of the extraction methods of phycocyanin pigments in eutrophic lake waters

2014 ◽  
Vol 26 (5) ◽  
pp. 799-806 ◽  
Author(s):  
PANG Xiaoyu ◽  
◽  
DUAN Hongtao ◽  
ZHANG Yuchao ◽  
MA Ronghua
Keyword(s):  
Eutrophic Lake ◽  
Extraction Methods ◽  
Lake Waters

scholarly journals The changes in the number and physiological properties of fungi in lakes differing in trophicity

2014 ◽  
Vol 29 (1) ◽  
pp. 33-42 ◽  
Author(s):  
Teresa Korniłłowicz
Keyword(s):  
Littoral Zone ◽  
Eutrophic Lake ◽  
Frequency Of Occurrence ◽  
Mesotrophic Lake ◽  
Physiological Properties ◽  
Lake Waters

U was demonstrated that the fungi decomposing protein were most abundant in tbe mesotrophic lake, whereas the fungi decomposing pectin dominated in the eutrophic lake. The accumulation of fungi mineralizing protein in littoral zone (metha- and hypolimnion of pelagial zone) of the mesotropbic lake indicated the increase in the fertility of this reservoir. The frequency of occurrence of physiologically differentiated mycoflora in the lake waters was seasonal and revealed fluctuations in their activity depending on the year of the study. These fluctuations were stronger in the mesotrophic lake.

scholarly journals Monitoring Water Transparency in Shallow and Eutrophic Lake Waters Based on GOCI Observations

2020 ◽  
Vol 12 (1) ◽  
pp. 163 ◽  
Author(s):  
Shuying Bai ◽  
Jixi Gao ◽  
Deyong Sun ◽  
Meirong Tian
Keyword(s):  
Remote Sensing ◽  
Lake Taihu ◽  
Eutrophic Lake ◽  
Temporal Variations ◽  
Water Transparency ◽  
Percentage Error ◽  
Study Region ◽  
Water Column Stability ◽  
Lake Waters

Water transparency represented by the Secchi disk depth (Zsd) plays an important role in understanding water ecology environment variations, especially for optically complex and shallow lake waters. In this study, using in situ measured remote sensing reflectance (Rrs), diffuse attenuation coefficient (Kd), and Zsd data collected in Lake Taihu (China), a regional algorithm for estimating Kd from Rrs was designed, and the semi-analytical model proposed by Lee et al. (2015) (hereafter called Lee_2015 model) was refined using a linear scaling correction for remote sensing of Zsd. The results showed that a good agreement between the derived Kd and in situ measured data (mean absolute percentage error (MAPE) = 26% for Kd(490); MAPE < 5% for Kd at 443, 555, and 660 nm). The in situ Rrs-derived Zsd results using the refined Lee_2015 model compared well with the in situ measured Zsd (R2 = 0.72 and MAPE = 36%), which was an obvious improvement over the Lee_2015 model in our study region. Subsequently, the refined Lee_2015 model was applied to the geostationary ocean color imager (GOCI) observations between 2012 and 2018 to yield the spatial and temporal variations of water transparency in the Lake Taihu waters. The long-term mean distribution of Zsd revealed that water transparency values in the northeastern Lake Taihu were generally higher than those in the southwest part. Monthly climatological Zsd patterns suggested that the Zsd distributions had large temporal variability, and distinct monthly patterns of Zsd existed in different subregions of Lake Taihu. The significant interannual variations of Zsd in Lake Taihu are probably affected by a combination of the water column stability mainly caused by wind, water temperature, human activity, and riverine discharge. The present study can provide a new approach for quantifying water visibility and serve for water-color remote sensing of optically complex and highly turbid waters.

Factors influencing release of phosphorus from sediments in a high productive polymictic lake system

2009 ◽  
Vol 60 (4) ◽  
pp. 1013-1023 ◽  
Author(s):  
S. U. Solim ◽  
A. Wanganeo
Keyword(s):  
Bottom Sediments ◽  
Lake Water ◽  
Nitrate Nitrogen ◽  
Significant Proportion ◽  
Eutrophic Lake ◽  
Sediment Layer ◽  
Release Rates ◽  
P Release ◽  
Short Period ◽  
Lake Waters

Phosphorus (P) release rates from bottom sediments are high (20.6 mg/m2/day) in Dal Lake (India), a polymictic hyper-eutrophic lake. These gross release rates occur over a period of 72 days during summer only. Likewise, a net internal load of 11.3 tons was obtained from mass balance estimates. Significant proportion i.e. ∼ 80% of 287.3 tons/yr of nitrate nitrogen (NO3-N) load is either eliminated by denitrification or gets entrapped for a short period in high macrophyte biomass of 3.2 kg/m2 f.w., which eventually get decomposed and nitrogen (N) is released back. These processes result in low lake water NO3-N concentrations which potentially influence sediment phosphorus (P) release. Especially, nitrate nitrogen (NO3-N) &lt;500 μg/L in the lake waters were associated with high P concentrations. Phosphorus was also observed to increase significantly in relation to temperature and pH, and it seems likely that release of phosphorus and ammonical nitrogen (NH4-N) depend on decomposition of rich reserves of organic matter (893 tons d.w. in superficial 10-cm bottom sediment layer). Lake P concentrations were significantly predicted by a multivariate regression model developed for the lake. This study describes significance of various lake water variables in relation to P-release from bottom sediments.

The effect of different extraction methods on chemical composition profile and pharmacological activities of essential oils and hydrosols

Planta Medica ◽  
2016 ◽  
Vol 81 (S 01) ◽  
pp. S1-S381
Author(s):  
F Ghavidel ◽  
MM Zarshenas ◽  
A Sakhteman ◽  
A Gholami ◽  
Y Ghasemi ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Essential Oils ◽  
Extraction Methods ◽  
Composition Profile ◽  
Pharmacological Activities

Characterization of dissolved organic matter (DOM) extracted from soils by hot water percolation (HWP)

2010 ◽  
Vol 59 (1) ◽  
pp. 99-108 ◽  
Author(s):  
M. Takács ◽  
Gy. Füleky
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Natural Organic Matter ◽  
Extraction Methods ◽  
Soil Samples ◽  
Hot Water ◽  
Soil Extracts ◽  
Water Percolation ◽  
Soil Humic Acid

The Hot Water Percolation (HWP) technique for preparing soil extracts has several advantages: it is easily carried out, fast, and several parameters can be measured from the same solution. The object of this study was to examine the possible use of HWP extracts for the characterization of soil organic matter. The HPLC-SEC chromatograms, UV-VIS and fluorescence properties of the HWP extracts were studied and the results were compared with those of the International Humic Substances Society (IHSS) Soil Humic Acid (HA), IHSS Soil Fulvic Acid (FA) and IHSS Suwannee Natural Organic Matter (NOM) standards as well as their HA counterparts isolated by traditional extraction methods from the original soil samples. The DOM of the HWP solution is probably a mixture of organic materials, which have some characteristics similar to the Soil FA fractions and NOM. The HWP extracted organic material can be studied and characterized using simple techniques, like UV-VIS and fluorescence spectroscopy.

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