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.

Reduction of Cladophora Biomass and Tissue Phosphorus in Lake Ontario, 1972–83

1987 ◽  
Vol 44 (12) ◽  
pp. 2212-2215 ◽  
Author(s):  
D. S. Painter ◽  
G. Kamaitis
Keyword(s):  
Soluble Reactive Phosphorus ◽  
Lake Ontario ◽  
Sampling Period ◽  
Dry Weight ◽  
Weight Basis ◽  
Remote Site ◽  
Net Production ◽  
Control Programs ◽  
Reactive Phosphorus ◽  
Tissue Phosphorus

Cladophora biomass and tissue phosphorus concentrations at seven sites in Lake Ontario have decreased from 1972 to 1983 in response to phosphorus control programs introduced in the early 1970's. Biomass and tissue phosphorus were significantly different between 1972 and 1982–83 (ANOVA, P < 0.001) but not significantly different between 1982 and 1983. The lakewide average tissue phosphorus was 0.49% in 1972 but by 1982 and 1983 had dropped to 0.26 and 0.20%, respectively, on an ash-free dry weight basis. Tissue phosphorus concentrations did not limit growth in 1972 but in 1983 had begun to limit growth. Model-predicted net production for a 6-wk sampling period in 1983 was 1.7 times greater in the western end of the lake than at a remote site in eastern Lake Ontario due to higher soluble reactive phosphorus concentrations.

scholarly journals DETECTION OF MICROBIAL CONTAMINATION IN COLLECTED RAINWATER IN GROUND RESERVOIRS BESIDE MAIN ROADS (ASBAYYA- GHARIAN- MAZDAH)

2018 ◽  
Vol 1 (1) ◽  
pp. 105-110
Author(s):  
Adel Saeeda ◽  
Ismail Futuristic
Keyword(s):  
Statistical Analysis ◽  
Bacterial Growth ◽  
Water Samples ◽  
Microbial Contamination ◽  
External Contamination ◽  
The Road ◽  
Glass Bottles

This study is conducted to investigate the extent to which water was contaminated with colon bacteria in ground tanks that extend along the Asbayya-Gharian and Gharyan- Mazdah roads. 20 samples were collected from the collected water pools in the ground reservoirs along the road and also 20 samples of water collected in ground reservoirs along the (Greian-Mazdah) between March and August. The samples were taken by sterilized glass bottles. The sterilized bottle was sealed in water, then, opened inside the tank to enter the water directly and prevent the possibility of external contamination. The samples were placed in the refrigerated case to prevent undergoing bacterial growth. The samples were taken to the laboratory for further investigation and defined for positive/negative samples containing colon bacteria. Statistical analysis of the study found that 20% of the water samples taken from the tanks along the Asbayya- Gharian road were not suitable for drinking, and 37% of the water samples from the Western Mountain Road area were not suitable for drinking. Because it contains a high percentage of colon bacteria.

An analytical method for shipboard extraction of the odour compounds, 2-methylisoborneol and geosmin

2004 ◽  
Vol 49 (9) ◽  
pp. 121-127 ◽  
Author(s):  
B. Brownlee ◽  
G. MacInnis ◽  
M. Charlton ◽  
S. Watson ◽  
S. Hamilton-Browne ◽  
...  
Keyword(s):  
Lake Water ◽  
Water Samples ◽  
Analytical Method ◽  
Lake Ontario ◽  
Eastern Region ◽  
Reliable Determination ◽  
Apparent Loss ◽  
Central Regions ◽  
Better Than ◽  
St Lawrence River

Extractions for the analysis of geosmin and 2-methylisoborneol (MIB) were carried out on board a research vessel by extracting water samples in the collection bottles with dichloromethane. The extracts are stable and can be stored for up to two months with no apparent loss of analytes. Workup and analysis could be done at the rate 15-20 samples per week. Approximately 150 samples from Lake Ontario were analyzed in 2000 and 120 samples in 2001. Concentrations as low as 1 ng/L could be detected, but reliable determination was only attained above 5 ng/L (&gt; 80% qualifier ion match within ±50%). Reproducibility between duplicates was generally better than 10%, and recovery of surrogate standards from reagent water averaged ca. 80% and from lake water ca. 60%. In early September, 2000, geosmin concentrations in Lake Ontario ranged from 1-13 ng/L and MIB from 1-31 ng/L. In 2001, the ranges were 1-47 and 1-56 ng/L for geosmin and MIB, respectively. Lowest concentrations occurred in the western and central regions and highest concentrations in the eastern region and St Lawrence River.

Identification and Quantification of Fecal Coliforms using Violet Red Bile Agar at Elevated Temperature

1976 ◽  
Vol 39 (11) ◽  
pp. 768-770 ◽  
Author(s):  
HARVEY KLEIN ◽  
DANIEL Y. C. FUNG
Keyword(s):  
Escherichia Coli ◽  
Statistical Analysis ◽  
Elevated Temperature ◽  
Water Samples ◽  
Colony Size ◽  
Enterobacter Aerogenes ◽  
The Other ◽  
Fecal Coliforms ◽  
Practical Usefulness ◽  
Identification And Quantification

A procedure was developed for identification and quantification of fecal coliforms by colony size obtained in Violet Red Bile agar incubated at 44.5 ± 0.5 C for 24 h in an air incubator. Five strains of Escherichia coli, 5 strains of Enterobacter aerogenes, 37 coliform isolates from sewage, and 76 coliform isolates from water were tested by this procedure. The practical usefulness of this procedure was studied by comparative quantification of 11 water samples using this procedure, the Millipore method, and MPN method. Statistical analysis showed that this procedure is as reliable as the other procedures for enumeration of fecal coliforms. The advantages of this method over the commonly used methods of enumeration of fecal coliforms are ease of operation, simplicity, and speed.

Response of Lake Ontario to Reductions in Phosphorus Load, 1967–82

1987 ◽  
Vol 44 (12) ◽  
pp. 2059-2068 ◽  
Author(s):  
R. J. J. Stevens ◽  
M. A. Neilson
Keyword(s):  
Response Time ◽  
Multiple Regression ◽  
Total Phosphorus ◽  
Algal Biomass ◽  
Soluble Reactive Phosphorus ◽  
Lake Ontario ◽  
Multiple Regression Equation ◽  
Phosphorus Load ◽  
N:P Ratios ◽  
Reactive Phosphorus

Total phosphorus (TP) loading to Lake Ontario has declined from 14 600 t∙yr−1 in 1969 to 8900 t∙yr−1 in 1982. Midlake spring TP has responded rapidly to these reductions, decreasing at the rate of 1.09 μg∙L−1∙yr−1 from a maximum of 30.6 μg∙L−1 in 1973 to 12.8 μg∙L−1 in 1982. Spring soluble reactive phosphorus (SRP) exhibited a proportionally larger decrease than TP such that 1982 SRP was 33% of 1973 levels, compared with 42% for TP. A multiple regression equation indicated an 80% response time of spring TP within 2 yr and a 90% response time within 4 yr. Spring nitrate plus nitrite has increased since 1969 at the rate of 9.5 μg∙L−1∙yr−1 causing N:P ratios to increase from 10 to 32. Mean summer epilimnetic TP declined at the rate of only 0.3 μg∙L−1∙yr−1 from 1977 to 1982 so that mean summer TP levels now exceed spring TP by 1–2 μg∙L−1. This suggests that loading to the lake during the stratified period has not shown a similar decline and may be responsible for the lack of a trend in algal biomass indicators during this period.

Spatial Heterogeneity of Nutrients and Organic Matter in Lake Ontario

1987 ◽  
Vol 44 (12) ◽  
pp. 2192-2203 ◽  
Author(s):  
M. A. Neilson ◽  
R. J. J. Stevens
Keyword(s):  
Organic Matter ◽  
Soluble Reactive Phosphorus ◽  
Lake Ontario ◽  
Nepheloid Layer ◽  
Niagara River ◽  
Water Column Stability ◽  
Phytoplankton Species Composition ◽  
Reactive Silica ◽  
Spring Lake ◽  
Reactive Phosphorus

During spring, Lake Ontario was vertically homogeneous except for the bottom 2 m where soluble reactive silica (SRS) and temperature (TEMP) were significantly (p < 0.05) elevated and dissolved oxygen was depleted. With stratification, soluble reactive phosphorus (SRP) and total filtered phosphorus, SRS, and nitrate-plus-nitrite were depleted in the epilimnion due to phytoplankton uptake. Total unfiltered phosphorus (TP) and ammonia (NH3) exhibited higher epilimnetic concentrations, the former being attributed to tributary inputs which were maintained throughout the stratified period, even though inputs from Niagara River served to dilute the epilimnion. Increased levels of TP, SRP, and SRS were also evident within the nepheloid layer. Horizontal distributions of TP and NH3 were governed by point-source inputs throughout the study period. Distributions of the soluble nutrients were governed by phytoplankton uptake in the spring, point/nonpoint inputs and upwelling in the summer, and differential breakdown of stratification in the fall. Spring distribution of particulate organic matter (POM) was strongly related to nutrient availability and water column stability, while phytoplankton species composition determined fall POM distribution. Significantly higher (p < 0.05) POM levels, detrital content, and productivity were observed nearshore of the thermal bar.

scholarly journals Limnology of a conserved man-made lake in Bangladesh. I. Physical and chemical factors

2012 ◽  
Vol 21 (2) ◽  
pp. 131-140 ◽  
Author(s):  
Roksana Begum ◽  
Moniruzzaman Khondker ◽  
Md Shafiqul Islam
Keyword(s):  
Water Temperature ◽  
Lake Water ◽  
Nitrate Nitrogen ◽  
Soluble Reactive Phosphorus ◽  
Seasonal Fluctuations ◽  
Chemical Factors ◽  
Reactive Phosphorus ◽  
Ph Range ◽  
Physical And Chemical ◽  
Limnological Parameters

Limnological investigation on a conserved man?made lake located in the Safipur Ansar and VDP Academy, Gazipur district has been carried out between July, 2008 and May, 2009. Thirteen limnological parameters were measured mostly at fortnight intervals and their annual and seasonal fluctuations were observed. The lake water was slightly alkaline in nature having a monthly mean pH range 7.26 ? 7.91. The water temperature varied from 18 ? 32°C. Soluble reactive phosphorus, soluble reactive silicate and nitrate nitrogen ranged from 9.22 ? 154.57 ?g/l, 2.52 ? 17.06 and 0.17 ? 187 mg/l, respectively.DOI: http://dx.doi.org/10.3329/dujbs.v21i2.11511Dhaka Univ. J. Biol. Sci. 21(2): 131-140, 2012 (July)

Temporal variability of disinfection by-products concentration in urban public water system

2013 ◽  
Vol 14 (4) ◽  
pp. 393-398
Keyword(s):  
Drinking Water ◽  
Water Samples ◽  
Temporal Variability ◽  
Water System ◽  
The Other ◽  
Major Constituent ◽  
System P ◽  
Public Water System ◽  
Drinking Water Samples ◽  
By Products

The occurrence of trihalomethanes (THMs) was studied in the drinking water samples from urban water supply network of Karachi city that served more than 18 million people. Drinking water samples were collected from 58 locations in summer (May-August) and winter (November-February) seasons. The major constituent of THMs detected was chloroform in winter (92.34%) and summer (93.07%), while the other THMs determined at lower concentrations. Summer and winter concentrations of total THMs at places exceed the levels regulated by UEPA (80 μg l-1) and WHO (100 μg l-1). GIS linked temporal variability in two seasons showed significantly higher median concentration (2.5%-23.06%) of THMs compared to winter.

Identification of Taste and Odour Compounds from Western Lake Ontario

1984 ◽  
Vol 19 (1) ◽  
pp. 111-118 ◽  
Author(s):  
B.G. Brownlee ◽  
D.S. Painter ◽  
R.J. Boone
Keyword(s):  
Water Supply ◽  
Water Samples ◽  
Elemental Sulfur ◽  
Lake Ontario ◽  
Direct Link ◽  
Municipal Water Supply ◽  
Municipal Water ◽  
Western Lake ◽  
Odour Concentration

Abstract During August, 1983 geosmin was identified in a municipal water supply drawn from western Lake Ontario. The geosmin concentrations were 0.01-0.07 μg L-1, within the range for threshold odour concentration of 0.01-0.2 μg L-1. 2-Methylisoborneol was not detected. The odour 'event' coincided with a dieoff of Cladophora in the lake, but we were not able to establish a direct link between the dieoff and geosmin production. Decomposing Cladophora in shoreline areas produced a strong odour in the air. 3-Methylindole, elemental sulfur, dimethyl tetrasulfide, and dimethyl pentasulfide were tentatively identified in water samples collected from these areas, but geosmin and 2-methylisoborneol were not detected.

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