scholarly journals Changes of the nutrient loads of the Odra River during the last century - their causes and consequences

2008 ◽  
Vol 12 (1) ◽  
pp. 127-144 ◽  
Author(s):  
Horst Behrendt ◽  
Dieter Opitz ◽  
Agnieszka Kolanek ◽  
Rafalina Korol ◽  
Marzenna Strońska
Keyword(s):  
Point Source ◽  
Total Phosphorus ◽  
Inorganic Nitrogen ◽  
Nutrient Loads ◽  
Dissolved Inorganic Nitrogen ◽  
Total N ◽  
Odra River ◽  
Time Periods ◽  
Total P ◽  
Point Source Discharges

Changes of the nutrient loads of the Odra River during the last century - their causes and consequencesNutrient emissions by point and diffuse sources and their loads were estimated for the Odra catchment over the time period of the last 50 years by means of the model MONERIS. For nitrogen a change of the total emissions from 38 kt·a−1N in the mid of 1950s a maximum of 105 kt·a−1N in the early 1980s and a recent value of about 84 kt·a−1N were estimated for the total Odra Basin. The share of the point source discharges on the total N emissions varied between 24% (1955) and 35% (1995). The emissions from groundwater and tile drained areas represent the dominant pathway (37-56% of total N emissions) during all investigated time periods. Emissions from tile drained areas increased from the mid of 1950s to end of 1980s by a factor of 20 and reached in this period the same amount as emissions by groundwater. For phosphorus the emissions changed from 4 kt·a−1P in 1955 to 14 kt·a−1P in 1990 and a recent level of 7 kt·a−1P. Point source discharges caused between 36 to 66% of total P emissions and represent the dominant pathway for all investigated time periods. Erosion and discharges from paved urban areas and sewer systems was the dominant diffuse pathway of the total P emissions into the river system. The comparison of calculated and observed nutrient loads for the main monitoring stations along the Odra River shows that the average deviation is 12% for total phosphorus (1980-2000) and 15% for dissolved inorganic nitrogen (1960-2000). From the analysis it can be concluded that the present load of dissolved inorganic nitrogen (DIN) and total nitrogen (TN) of the Odra into the Baltic Sea is about 2.3 times higher than in the mid of 1960s. The maximum DIN load (1980s) was more than 3 times higher than in the 1960s. The change of the total phosphorus (TP) load is characterized by an increase from the 1955s to 1980 from 2 to 7 kt·a−1P (factor 2.6). Around 2000 the TP load was 4 kt·a−1which is only the double of the level of the 1955s.

Characteristics of Non-Point Source N Export via Surface Runoff from Sloping Croplands in Northeast China

2011 ◽  
Vol 347-353 ◽  
pp. 2302-2307 ◽  
Author(s):  
Hong Xiang Wang ◽  
Yi Shi ◽  
Jian Ma ◽  
Cai Yan Lu ◽  
Xin Chen
Keyword(s):  
Point Source ◽  
Surface Runoff ◽  
Rainfall Intensity ◽  
Inorganic Nitrogen ◽  
Rainfall Amount ◽  
Organic N ◽  
Dissolved Inorganic Nitrogen ◽  
Slope Gradient ◽  
N Loss ◽  
Total N

A field experiment was conducted to study the characteristics of non-point source nitrogen (N) in the surface runoff from sloping croplands and the influences of rainfall and cropland slope gradient. The results showed that dissolved total N (DTN) was the major form of N in the runoff, and the proportion occupied by dissolved inorganic nitrogen (DIN) ranged from 45% to 85%. The level of NH4+-N was generally higher than the level of NO3--N, and averaged at 2.50 mg·L-1and 1.07 mg·L-1respectively. DIN was positively correlated with DTN (R2=0.962). Dissolved organic N (DON) presented a moderate seasonal change and averaged at 1.40 mg·L-1. Rainfall amount and rainfall intensity significantly affected the components of DTN in the runoff. With the increase of rainfall amount and rainfall intensity, the concentrations of DTN, NH4+-N and NO3--N presented a decreased trend, while the concentration of DON showed an increased trend. N loss went up with an increase in the gradient of sloping cropland, and was less when the duration was longer from the time of N fertilization.fertilization.

Cumulative effects of pulp mill and municipal effluents on epilithic biomass and nutrient limitation in a large northern river ecosystem

2000 ◽  
Vol 57 (7) ◽  
pp. 1342-1354 ◽  
Author(s):  
Garry J Scrimgeour ◽  
Patricia A Chambers
Keyword(s):  
Point Source ◽  
Nutrient Limitation ◽  
Large Scale ◽  
Function Analysis ◽  
Inorganic Nitrogen ◽  
Soluble Reactive Phosphorus ◽  
Pulp Mill ◽  
Nutrient Status ◽  
Dissolved Inorganic Nitrogen ◽  
Reactive Phosphorus

Large-scale patterns in epilithic biomass and nutrient status were evaluated at 33 sites located upstream and downstream of point-source anthropogenic effluents in the Athabasca and Wapiti-Smoky rivers in Alberta, Canada. Multiple regression showed that epilithic chlorophyll a was significantly (p < 0.0001) related to concentrations of dissolved inorganic nitrogen and marginally (p = 0.06) significantly related to soluble reactive phosphorus. Epilithic biomass was up to 50 times higher immediately downstream of point-source inputs compared with sites upstream and those 20-150 km downstream. Data from nutrient diffusing substrata showed that the epilithon at 18 of the 33 sites was nutrient limited, while 14 sites showed no nutrient limitation; interpretation of the remaining site was inconclusive. Of the 18 nutrient-limited sites, six were nitrogen limited, five were phosphorus limited, and seven were co-limited. Multiple discriminant function analysis showed that the combined concentration of soluble reactive phosphorus and dissolved inorganic nitrogen was a significant discriminator between deplete and replete sites.

scholarly journals Threshold values and management options for nutrients in a catchment of a temperate estuary with poor ecological status

2012 ◽  
Vol 9 (2) ◽  
pp. 2157-2211
Author(s):  
K. Hinsby ◽  
S. Markager ◽  
B. Kronvang ◽  
J. Windolf ◽  
T. O. Sonnenborg ◽  
...  
Keyword(s):  
Algal Blooms ◽  
Climate Models ◽  
Ecological Status ◽  
Water Clarity ◽  
Nutrient Loads ◽  
Threshold Values ◽  
Management Options ◽  
Total N ◽  
Good Ecological Status ◽  
Total P

Abstract. Intensive farming has severe impacts on the chemical status of groundwater and streams and consequently on the ecological status of dependent ecosystems. Eutrophication is a widespread problem in lakes and marine waters. Common problems are hypoxia, algal blooms and fish kills, and loss of water clarity, underwater vegetation, biodiversity, and recreational value. In this paper we evaluate the nitrogen (N) and phosphorus (P) chemistry of groundwater and surface water in a coastal catchment, the loadings and sources of N and P and their effect on the ecological status of an estuary. We calculate the necessary reductions in N and P loadings to the estuary for obtaining a good ecological status, which we define based on the number of days with N and P limitation, and the equivalent stream and groundwater threshold values assuming two different management options. The calculations are performed by the combined use of empirical models and a physically based 3-D integrated hydrological model of the whole catchment. The assessment of the ecological status indicates that the N and P loads to the investigated estuary should be reduced by a factor of 0.52 and 0.56, respectively, to restore good ecological status. Model estimates show that threshold total N concentrations should be in the range of 2.9 to 3.1 mg l−1 in inlet freshwater to Horsens Estuary and 6.0 to 9.3 mg l−1 in shallow aerobic groundwater (∼27–41 mg l−1 of nitrate), depending on the management measures implemented in the catchment. The situation for total P is more complex but data indicate that groundwater threshold values are not needed. The inlet freshwater threshold value for total P to Horsens Estuary for the selected management options is 0.084 mg l−1. Regional climate models project increasing winter precipitation and runoff in the investigated region resulting in increasing runoff and nutrient loads to coastal waters if present land use and farming practices continue. Hence, lower threshold values are required in the future to ensure good status of all water bodies and ecosystems.

Nutrient status of Lake Liddel, New South Wales: mass loadings of nitrogen and phosphurus, industrial modification, and trophic state

1992 ◽  
Vol 43 (2) ◽  
pp. 443 ◽  
Author(s):  
RN Royle ◽  
RJ King
Keyword(s):  
Point Source ◽  
New South ◽  
Nutrient Status ◽  
Nutrient Concentrations ◽  
Nitrogen And Phosphorus ◽  
Total N ◽  
South Wales ◽  
Annual Total ◽  
The Mean ◽  
Total P

The concentrations of nitratehitrite-N, Kjeldahl-N and total P in point-source additions to and losses from Lake Liddell (32° 22'S,150° 1'E) were measured fortnightly from September 1987 to September 1988. These data were used in conjunction with flow-rate data to construct a nitrogen and phosphorus budget from Lake Liddell. The annual net point-source loadings of nitrogen and phosphorus were 23 400 and 5700 kg, respectively. There was little relationship between changes in lake nutrient concentrations and fortnightly mass loadings. The mean molar N: P ratio for point source mass additions was 13: 1, whereas that within the lake was 33: 1. These features indicate that within-lake processes were the dominant processes in determining lake nutrient concentrations. Retention in the sediments of a greater proportion of the total P pool than of the total-N pool appeared to be one of these processes. The use of Lake Liddell water in power-station operations resulted in substantial increases in nitrate/ nitrite-N and total-P concentrations in waters returned to the lake. The use of Dillon's model to predict mean annual total-P concentrations from mass loadings indicates that Lake Liddell is on the border between mesotrophic and eutrophic states.

scholarly journals The impacts of global and local change on a tropical lake over forty years

2020 ◽  
Author(s):  
Jemma M. Fadum ◽  
Ed K. Hall
Keyword(s):  
Total Phosphorus ◽  
Trophic State ◽  
Inorganic Nitrogen ◽  
Secchi Depth ◽  
Water Clarity ◽  
Physical Structure ◽  
Tropical Lake ◽  
Dissolved Inorganic Nitrogen ◽  
Lake Ecosystems ◽  
Algal Productivity

AbstractLakes across the world are experiencing novel trophic states, declining water quality, and altered biogeochemical cycling due to the synergistic impacts of global change and local anthropogenic stressors. In the tropics these changes can be difficult to assess due to a lack of continuous monitoring or documented legacy conditions to serve as a reference for the contemporary lake. Over the last forty years, Lake Yojoa, located in west central Honduras, has shifted from an oligotrophic to mesotrophic ecosystem as evidenced by a loss of water clarity. To assess the changes that have occurred in Lake Yojoa as well as putative drivers for those changes, we compared secchi depth, dissolved inorganic nitrogen, and total phosphorus concentrations between 1979-1983 and today (2018-2020). While we found little change in total phosphorus between legacy and contemporary data, we found concurrent changes to seasonal trends in secchi depth and dissolved inorganic nitrogen (DIN). Seasonal peaks in DIN coincident with mixus suggest that accumulation of ammonium in the hypolimnion during stratification, and release to the epilimnion with mixus maintains algal productivity in what was previously a nutrient-limited, clear water phase, driving a change in the overall trophic state of Lake Yojoa. This impact of seasonal dynamics on the trophic state of the lake illustrates a key distinction in how physical structure and nutrients interact differently in tropical and temperate lake ecosystems and highlights the importance of warm anoxic hypolimnions to the biogeochemistry that governs the trophic state of tropical lake ecosystems.

scholarly journals Anaerobic biodigestion of manure from finishing pig supplemented with ractopamine over different periods

2016 ◽  
Vol 36 (3) ◽  
pp. 399-407 ◽  
Author(s):  
Tânia M. B. dos Santos ◽  
Paula S. F. Trevizan ◽  
Cristiane A. N. Xavier ◽  
Charles Kiefer ◽  
André L. J. Ferraz
Keyword(s):  
Anaerobic Digestion ◽  
Total Nitrogen ◽  
Total Phosphorus ◽  
Biogas Production ◽  
Finishing Pigs ◽  
Ammoniacal Nitrogen ◽  
Total N ◽  
Volatile Solids ◽  
Finishing Pig ◽  
Total P

ABSTRACT This study aimed to evaluate the efficiency of anaerobic digestion and biogas production by manure from pig supplemented with ractopamine over different periods. We used manure of 50 finishing pigs according to the following diets: without supplementation and supplemented with 20-ppm ractopamine during 7, 14, 21, 28 and 35 days pre-slaughter. Continuous bench biodigesters were used in the experiment. We measured biogas production and made analyses of total (TS) and volatile solids (VS), pH, total phosphorus (total P), total nitrogen (total N) and ammoniacal nitrogen (ammoniacal N) in samples of manure, affluent and effluent from biodigesters. The pH and ammoniacal N as indicator parameters of the process balance and stability were satisfactory. Moreover, there was no difference in the reduction of TS and VS (50.04 and 56.51%, respectively). Manure of animals supplemented with ractopamine for 35 and 28 days presented higher biogas production (0.0722 and 0.0603 m3 kg−1, respectively). The supplementation with 20-ppm ractopamine for finishing pigs from 7 to 35 days does not present collapse risks for the anaerobic biodigestion process.

scholarly journals Seasonal Occurrence of Cyanobacteria and First Detection of Microcystin-LR in Water Column of Foum-Gleita Reservoir, Mauritania

2021 ◽  
Author(s):  
Ahmed Sidi Sadegh ◽  
Zeinebou Sidoumou ◽  
Mamadou Dia ◽  
Juan Luis Gómez Pinchetti ◽  
Noureddine Bouaïcha
Keyword(s):  
Surface Water ◽  
Environmental Factors ◽  
Water Column ◽  
Microcystis Aeruginosa ◽  
Total Phosphorus ◽  
Inorganic Nitrogen ◽  
Cyanobacterial Blooms ◽  
World Health ◽  
Seasonal Occurrence ◽  
Dissolved Inorganic Nitrogen

Abstract This work was carried out to study the seasonal occurrence of cyanobacteria and their microcystin-LR in water column of Foum-Gleita reservoir (Mauritania). Limnological and biological factors were investigated at three depths (surface, -3, and -6 m) in this reservoir during a full year. Nutrients were analyzed by Spectrophotometry, phytoplankton was analyzed by Inverted Microscopy, microsystins were analyzed by High Performance Liquid Chromatography-tandem Mass Spectrometry and environmental factors relationships were analyzed by Pearson's correlation and Multiple Linear Regression. Physicochemical analyzes have shown that this reservoir is hypereutrophic with dissolved inorganic nitrogen and total phosphorus concentrations relatively high, varying from 1.39 to 6.53 and 0.21 to 0.57 mg/L, respectively. Annual surface water temperature was exceptionally high (27.8 ± 3.6°C), characterizing of a Sahelian climatic conditions. Phytoplankton analyzes have shown dominance of two toxic cyanobacteria species Microcystis aeruginosa and Dolichospermum flos-aquae during warm season (May-September). Microcystins analysis revealed presence of only most toxic variant, microcystin-LR. Microcystin-LR concentration in the surface water samples, during cyanobacterial blooms, was consistently high (5.638 µg/L), exceeding 5-times the World Health Organization drinking water limit (1 µg/L), however, it was much lower (0.83 µg / L) at depth (-6 m). Analysis of environmental factors relationships showed that the most influential factors on abundance of Microcystis aeruginosa and Dolichospermum flos-aquae and variability of microcystin-LR concentrations were total phosphorus, dissolved inorganic nitrogen, iron, temperature and pH. Finally, the study clearly demonstrated need for regular monitoring of cyanobacteria and cyanotoxins in the waters of studied reservoir.

Trend-analysis of eutrophication variables in lakes in The Netherlands

1998 ◽  
Vol 37 (3) ◽  
pp. 235-240 ◽  
Author(s):  
Rob Portielje ◽  
Diederik T. Van der Molen
Keyword(s):  
The Netherlands ◽  
Trend Analysis ◽  
Chlorophyll A ◽  
Total Nitrogen ◽  
Total Phosphorus ◽  
Negative Trend ◽  
Total N ◽  
Total P

A trend-analysis of eutrophication variables was performed for a large number of lakes in The Netherlands. Data of in total 231 lakes were available. Data on chlorophyll-a, total phosphorus (total-P) and total nitrogen (total-N) were analysed over the period 1980-1996. Summer-averaged concentrations for chlorophyll-a, total-P and total-N decreased in respectively 65%, 73% and 75 of the lakes with at least eight years data between 1980 and 1996. Results for winter means were comparable (a negative trend in 54%, 77% and 69% for concentrations of chlorophyll-a, total-P and total-N respectively). Since 1980 the median decrease in the summer averaged concentrations of chlorophyll-a, total-P and total-N is 2.61 μg l−1 y−1, 0.008 mg l−1 y−1 and 0.046 mg l−1 y−1, respectively, illustrating the effects of (inter)national and regional measures to combat eutrophication.

scholarly journals Catchment land use predicts benthic vegetation in small estuaries

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4378
Author(s):  
Perran L.M. Cook ◽  
Fiona Y. Warry ◽  
Paul Reich ◽  
Ralph Mac Nally ◽  
Ryan J. Woodland
Keyword(s):  
Land Use ◽  
Human Activities ◽  
Inorganic Nitrogen ◽  
Area Ratio ◽  
Nutrient Loads ◽  
Dissolved Inorganic Nitrogen ◽  
Flushing Time ◽  
Nitrogen Loads ◽  
Eastern Australia ◽  
Benthic Vegetation

Many estuaries are becoming increasingly eutrophic from human activities within their catchments. Nutrient loads often are used to assess risk of eutrophication to estuaries, but such data are expensive and time consuming to obtain. We compared the percent of fertilized land within a catchment, dissolved inorganic nitrogen loads, catchment to estuary area ratio and flushing time as predictors of the proportion of macroalgae to total vegetation within 14 estuaries in south-eastern Australia. The percent of fertilized land within the catchment was the best predictor of the proportion of macroalgae within the estuaries studied. There was a transition to a dominance of macroalgae once the proportion of fertilized land in the catchment exceeded 24%, highlighting the sensitivity of estuaries to catchment land use.

LAND USE TYPES AND SOIL CHARACTERISTICTS: A CASE STUDY IN HUONG VINH COMMUNE, HUONG TRA TOWN, THUA THIEN HUE PROVINCE

2017 ◽  
Vol 126 (4B) ◽  
Author(s):  
Trần Thanh Đức
Keyword(s):  
Land Use ◽  
Sweet Potato ◽  
Soil Analysis ◽  
Soil Characteristics ◽  
Low Ph ◽  
Clay Loam ◽  
Total N ◽  
Land Use Types ◽  
Total P

This research carried out in Huong Vinh commune, Huong Tra town, Thua Thien Hue province aimed to identify types of land use and soil characteristics. Results showed that five crops are found in Huong Vinh commune including rice, peanut, sweet potato, cassava and vegetable. There are two major soil orders with four soil suborders classified by FAO in Huong Vinh commune including Fluvisols (Dystric Fluvisols<em>, </em>Gleyic Fluvisols and Cambic Fluvisols) and Arenosols (Haplic Arenosols). The results from soil analysis showed that three soil suborders including Dystric Fluvisols<em>, </em>Gleyic Fluvisols and Cambic Fluvisols belonging to Fluvisols were clay loam in texture, low pH, low in OC, total N, total P<sub>2</sub>O<sub>5</sub> and total K<sub>2</sub>O. Meanwhile, the Haplic Arenosols was loamy sand in texture, poor capacity to hold OC, total N, total P<sub>2</sub>O<sub>5</sub> and total K<sub>2</sub>O

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