Multicomponent kinetic analysis of iron speciation in humic Lake Tjeukemeer: comparison of fulvic acid from the drainage basin and lake water samples

1991 ◽  
Vol 25 (5) ◽  
pp. 935-939 ◽  
Author(s):  
Luis E. Sojo ◽  
Henk De Haan
Keyword(s):  
Kinetic Analysis ◽  
Fulvic Acid ◽  
Lake Water ◽  
Water Samples ◽  
Drainage Basin ◽  
Humic Lake ◽  
Iron Speciation

Enumeration and Identification of Asbestos Fibres in Water

1974 ◽  
Vol 32 ◽  
pp. 526-527 ◽  
Author(s):  
O. Mudroch ◽  
J. R. Kramer
Keyword(s):  
Water Supply ◽  
Water Samples ◽  
Drainage Basin ◽  
Lake Superior ◽  
Research Work ◽  
List Type ◽  
The West ◽  
Asbestos Fibre ◽  
Amphibole Asbestos

Approximately 60,000 tons per day of waste from taconite mining, tailing, are added to the west arm of Lake Superior at Silver Bay. Tailings contain nearly the same amount of quartz and amphibole asbestos, cummingtonite and actinolite in fibrous form. Cummingtonite fibres from 0.01μm in length have been found in the water supply for Minnesota municipalities.The purpose of the research work was to develop a method for asbestos fibre counts and identification in water and apply it for the enumeration of fibres in water samples collected(a) at various stations in Lake Superior at two depth: lm and at the bottom.(b) from various rivers in Lake Superior Drainage Basin.

Changes in Nutrient Levels of Lake Water Stored at 4 °C

1984 ◽  
Vol 41 (6) ◽  
pp. 985-988 ◽  
Author(s):  
A. H. El-Shaarawi ◽  
M. A. Neilson
Keyword(s):  
Statistical Analysis ◽  
Lake Water ◽  
Water Samples ◽  
Soluble Reactive Phosphorus ◽  
Lake Ontario ◽  
The Other ◽  
Nutrient Levels ◽  
Glass Bottles ◽  
Reactive Phosphorus

Water samples were collected on Lake Ontario during April and November, filtered (0.45 μm), and immediately analyzed onboard ship for the nutrients soluble reactive phosphorus, nitrate-plus-nitrite, and ammonia. Replicates were stored in glass bottles at 4 °C and reanalyzed within 8 d. Statistical analysis showed that soluble reactive phosphorus decreased by 11 and 13% and nitrate-plus-nitrite by 7 and 6%, whereas ammonia increased by 75% on one cruise and decreased by 37% on the other.

Seasonal changes of fulvic acid, Ca and Mg concentrations of water samples collected above and in the Béke Cave of the Aggtelek karst system (Hungary)

2004 ◽  
Vol 19 (11) ◽  
pp. 1727-1733 ◽  
Author(s):  
Enikö Tatár ◽  
Victor G. Mihucz ◽  
László Zámbó ◽  
Tibor Gasparics ◽  
Gyula Záray
Keyword(s):  
Fulvic Acid ◽  
Water Samples ◽  
Seasonal Changes ◽  
Karst System

Status of Heavy Metal Contaminations of Lake Water of Dhaka Metropolitan City

2013 ◽  
Vol 5 (2) ◽  
pp. 345-348 ◽  
Author(s):  
MAA Mokaddes ◽  
BS Nahar ◽  
MA Baten
Keyword(s):  
Water Pollution ◽  
Heavy Metal ◽  
Chemical Analysis ◽  
Natural Resources ◽  
Lake Water ◽  
Water Samples ◽  
Ph Value ◽  
Central Laboratory ◽  
Metropolitan City

A study was conducted to evaluate level of water pollution and its influence on heavy metal contaminations of lake water of Dhaka metropolitan city. The water samples were collected from lakes of Dhaka metropolitan city during February to March, 2008. The chemical analysis of water samples included pH, EC, As, Cu, Mn, 'ln. Pb and Cd. Analysis of lake water samples was done at the Central Laboratory of Bangladesh Agricultural University, Mymensingh. The concentrations of heavy metal of lake water were recorded as: in case of pH = 6.95, in case of EC = 22.44 (?scm-1), in case of Cu = 0.018 ppm, in case of Zn = 0.274 ppm, in case of Mn = 0.084 ppm, in case of As = 0.002 ppb, in case of Pb = 0.002 ppm and in case of Cd = 0.044 ppm. The pH value of lakes water range from 5.34 to 7.68, an indication of slightly acidic to alkaline in nature. The average EC value for lakes water ranged from 17.61 to 34.61 ?Scm-1 where EC value varied from 14.24 to 33.48 ?Scm-1 in the lake water.DOI: http://dx.doi.org/10.3329/jesnr.v5i2.14841 J. Environ. Sci. & Natural Resources, 5(2): 345-348 2012

scholarly journals Introduction and Removal of Disinfection Byproducts and Mutagenic Activity by Chemical and Photolytic Treatments

2005 ◽  
Vol 8 (3) ◽  
pp. 387-401 ◽  
Author(s):  
P. Backlund
Keyword(s):  
Carboxylic Acids ◽  
Lake Water ◽  
Mutagenic Activity ◽  
Disinfection Byproducts ◽  
Humic Lake ◽  
River Waters ◽  
Precursor Material ◽  
Strong Mutagen ◽  
Organic Halogens ◽  
Higher Doses

Samples from four different raw water sources were treated with various disinfectants and subjected to chemical analyses and mutagenicity assays. The following disinfectants were used: chlorine (Cl2), chlorine dioxide (ClO2), monochloramine (NH2Cl), ozone (O3), ultraviolet radiation (UV), and combinations of Cl2/ClO2, O3/Cl2, UV/Cl2, and UV/O3/Cl2. The samples were analysed for adsorbable organic halogens (AOX), chloroform (CHCl3), carboxylic acids, volatile organics, chlorite, the strong mutagen 3-chloro-4 (dichloromethyl)-5-hydroxy-2 (5H)-furanone (MX), and mutagenic activity (as detected by the Ames test). Humic lake water which had been treated with the combination UV/Cl2 exhibited a higher level of mutagenicity and higher concentrations of MX and CHCl3 than water treated with Cl2 alone. The same observation was made for the mutagenicity and the CHCl3 concentration in waters preoxidized with low doses of O3 and UV/O3, respectively. When higher doses of these powerful oxidants were used in the pretreatment step, the level of mutagenicity, MX and CHCI3 were lower than in water chlorinated without pretreatment. The combination UV/O3 was found to be more efficient than O3 alone in destroying the precursor material to the mutagenic compounds and chloroform. The higher the proportion of ClO2 in the combined Cl2/ClO2 process, the lower the levels of mutagenicity, MX, CHCl3, and AOX. The production of inorganic chlorite increased with a higher proportion of ClO2. Aldehydes, n-alkanes, and low molecular-weight carboxylic acids were identified as byproducts following UV treatment of humic lake water. The mutagenic activity (per amount of DOC) was approximately similar after chlorination of humic rich surface- and ground waters as after chlorination of waters from the rivers Meuse and Rhine, containing relatively low amounts of humic matter. The precursors to MX were found to be more abundant in the humic waters than in the river waters.

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