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.

Full Scale Experiences with Nutrient Removal at Two Wastewater Treatment Plants in The Netherlands

1993 ◽  
Vol 27 (5-6) ◽  
pp. 343-355 ◽  
Author(s):  
H. Draaijer ◽  
A. H. M. Buunen-van Bergen ◽  
E. van't Oever ◽  
A. A. J. C. Schellen
Keyword(s):  
The Netherlands ◽  
Total Nitrogen ◽  
Wastewater Treatment Plants ◽  
Full Scale ◽  
Biological Phosphorus Removal ◽  
Nitrogen And Phosphorus ◽  
Total N ◽  
Side Stream ◽  
Biological Phosphorus ◽  
Total P

Two full scale projects are described in this paper; these are the Bergambacht wastewater plant (carrousel) and the Terneuzen wastewater plant (Schreiber system). Both plants use a system of intermittent aeration to combine nitrification and denitrification processes. At the Bergambacht plant biological phosphorus removal is carried out by the introduction of the side stream process. At the Terneuzen plant it is carried out by introducing anaerobic periods in the aeration tanks. The objective is to meet the new total nitrogen and phosphorus effluent standards in The Netherlands of resp. 10-15 and 1-2 mg/l. At the Terneuzen wastewater plant the standards could not be reached for total-nitrogen, mainly due to the low BOD to Kj-N ratio of 2:8 in the feed to the aeration tanks. Adjustments are suggested to improve the denitrification rate. At the Bergambacht wastewater plant effluent concentrations of 6 - 7 mg/l total N and 0.3 mg/l total P were achieved.

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 Effect of red algal bloom on growth and production of carps

Our Nature ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 48-54
Author(s):  
Ram Bhajan Mandal ◽  
Sunila Rai ◽  
Madhav Kumar Shrestha ◽  
Dilip Kumar Jha ◽  
Narayan Prasad Pandit
Keyword(s):  
Water Quality ◽  
Body Weight ◽  
Chlorophyll A ◽  
Total Nitrogen ◽  
Total Phosphorus ◽  
Algal Bloom ◽  
Total Dissolved Solids ◽  
Dissolved Solids ◽  
Aquaculture Farm ◽  
Red Algal

An experiment was carried to assess the effect of red algal bloom on growth and production of carp, water quality and profit from carp for 120 days at Aquaculture Farm of Agriculture and Forestry University, Chitwan. The experiment included two treatments: carp polyculture in non-red pond and carp polyculture in red pond with algal bloom each with three replicates. Carp fingerlings were stocked at 1 fish/m2 and fed with pellet containing 24% CP at 3% body weight. Net yield of rohu was found significantly higher (p<0.05) in non-red ponds (0.38±0.01 t ha-1) than red ponds (0.24±0.05 t ha-1). Survival of rohu (84.9±1.4%), bighead (95.2±2.0%) and mrigal (88.1±14.4%) were also significantly higher (p<0.05) in non-red ponds than red ponds. Red algal bloom affected DO, nitrate and chlorophyll-a, nitrite, total nitrogen, total phosphorus, total dissolved solids and conductivity. However, overall carp production and profit from carp remained unaffected.

Upscaling biomanipulation in 600 ha Lake Zuidlaardermeer

1995 ◽  
Vol 31 (8) ◽  
pp. 235-238
Author(s):  
C. Roos ◽  
M. Klinge ◽  
J. Heringa ◽  
D. A. de Vries ◽  
R. Torenbeek
Keyword(s):  
The Netherlands ◽  
Water Chemistry ◽  
Chlorophyll A ◽  
Fish Community ◽  
Submerged Macrophytes ◽  
Northern Pike ◽  
Emergent Vegetation ◽  
Ecological Rehabilitation ◽  
Significant Step ◽  
Total P

In the 600 ha Lake Zuidlaardermeer in The Netherlands enclosure experiments were carried out in order to test the feasibility of biomanipulation. In two enclosures of 625 m2 each the effects of reduction of fish and wind and waves on water chemistry, phyto- and zooplankton and submerged macrophytes were studied and compared to the lake. In the “fishless” enclosure transparency increased from 40 to 120 cm, chlorophyll-a dropped from 70 to 20 μg/l, total-P dropped from 0.20 to 0.10 mg/l, Daphnia sp. &gt; 1 mm increased from 30 to 130 individuals/l and submerged macrophytes returned. The “fish” enclosure largely behaved in a way intermediate between the “fishless” enclosure and the lake: transparency increased to 60 cm, chlorophyll-a dropped to 40 μg/l, total-P dropped to 0.12 mg/l and Daphnia sp. &gt; 1 mm increased to 80/l. Submerged macrophytes however did not develop. The experiments show the potential of the lake for ecological rehabilitation. Nevertheless the effect of wind and waves on a larger scale remains uncertain. Therefore plans have been made to build a larger enclosure (40–100 ha). In this way, the effects of fish and wind and waves can be studied on a larger scale while at the same time recovery of the submerged macrophytes within this enclosure will be a significant step towards ecological rehabilitation of the whole lake. Beside the return of the submerged macrophytes the management is also aimed at the development of substantial amounts of emergent vegetation, thus supporting enough Northern Pike (Esox lucius L.) for regulation of the planktivorous fish community.

scholarly journals Trophic Status and Phytoplankton Limitation Conditions in a Few Bulgarian and Hungarian Danube River Wetlands

2016 ◽  
Vol 18 (2) ◽  
pp. 19-28
Author(s):  
Roumen Kalchev ◽  
Árpád Berczik ◽  
Michaela Beshkova ◽  
Mária Dinka ◽  
Hristina Kalcheva ◽  
...  
Keyword(s):  
Chlorophyll A ◽  
Total Nitrogen ◽  
Total Phosphorus ◽  
Trophic State ◽  
Trophic Status ◽  
Danube River ◽  
Trophic State Index ◽  
Secchi Disk ◽  
State Index

Abstract The phytoplankton limitation conditions in a few Bulgarian and Hungarian wetlands and in two more sampling sites, one for each Danube stretch, were investigated by means of trophic state index of Carlson (1977) for phytoplankton chlorophyll-a (CHL), Secchi disk depths (SD), total phosphorus (TP), and total nitrogen (TN) concentrations. Phytoplankton of both river sites was not limited by non-algal turbidity, nor was they phosphorus and nitrogen limited. In summer months the studied wetlands were predominantly nitrogen limited, while in spring and autumn limitation by non-algal turbidity prevailed.

scholarly journals Cobia cage culture distribution mapping and carrying capacity assessment in Phu Quoc, Kien Giang province

2013 ◽  
Vol 4 (1) ◽  
pp. 12-19
Author(s):  
Hong Diep Nguyen ◽  
Glino Gallardo Wenresti ◽  
Kumar Tripathi Nitin ◽  
Hoang Minh Truong
Keyword(s):  
Chlorophyll A ◽  
Total Nitrogen ◽  
Total Phosphorus ◽  
Carrying Capacity ◽  
Water Environment ◽  
Cage Culture ◽  
Nitrogen And Phosphorus ◽  
Coastal Aquaculture ◽  
Distribution Mapping ◽  
Marine Culture

Cobia fish cage is the most popular marine culture species raised in Phu Quoc Island, Vietnam. For its sustainable development, there is a need to determine the carrying capacity to avoid negative marine environmental impact in the future. This study was carried out to collect water samples each two months at the lowest and highest tides at four points around the farming area in Rach Vem, Phu Quoc Island, Kien Giang Province from February to October 2011. Water quality in cobia cage culture was surveyed to assess the environmental status of coastal aquaculture areas including seven parameters such as DO, COD, BOD, TSS, TN, TP and Chlorophyll-a. These parameters are suitable to rear cobia fish cage in this area. Nitrogen and phosphorus are considered as the principal nutrients produced by the cobia fish farm and affecting water environment. This study found that the carrying capacity for fish cage farming in the area is 290.96 to 727.81 tons (based on total nitrogen) and 428.64 to 1,383.88 tons (based on total phosphorus) from February to Au-gust 2011. The maximum number of cobia cages should be, based on total nitrogen, from 64 to 266 and, based on total phosphorus, from 94 to 253. Moreover, this study examined the possibility of remote sensing and geographic information system (GIS) technique based on Object-based Image Analysis (OBIA) method by THEOS imagery for mapping of cage culture facilities and detect the location for cobia cage culture in study area. Cá bớp nuôi lồng bè là một trong những loài cá nuôi phổ biến khu vực ven biển Phú Quốc, Việt nam. Nhằm phát triển bền vững vùng ven biển, đề tài thực hiện đã xác định và đánh giá hiện trạng môi trường nước và sức tải môi trường của nghề nuôi cá bớp lồng bè ở đảo Phú Quốc. Nghiên cứu này được thực hiện thông qua việc thu mẫu môi trường nước mỗi 2 tháng theo mức nước triều cao nhất và thấp nhất tại 4 điểm quanh khu vực nuôi tại ấp Rạch Vẹm, huyện Phú Quốc, tỉnh Kiên Giang từ tháng 02-10/2011. Chất lượng nước khu vực nuôi thủy sản cũng được khảo sát với 7 chỉ tiêu gồm DO, COD, BOD, TSS, TN, TP, Chlorophyll-a. Các thông số chất lượng môi trường này phù hợp nuôi cá bớp tại khu vực nghiên cứu dựa trên tiêu chuẩn chất lượng môi trường. Trong nghiên cứu này, đạm và lân là 2 thông số được sử dụng để tính toán sức tải môi trường. Sức tải môi trường được tính toán cho khu vực nuôi cá bớp dao động khoảng từ 290.96 tấn đến 727.81 tấn (tính trên hàm lượng đạm tổng số) và từ 428,64 tấn đến 1.383,88 tấn (tính trên hàm lượng lân tổng số) trong thời gian từ tháng 2 đến tháng 10 năm 2011. Số lượng tối đa lồng bè nuôi cá bớp khoảng từ 64 đến 266 (đạm tổng số) và từ 94 đến 253 (lân tổng số) dựa vào phân tích hồi quy tương quan. Bên cạnh đó, công nghệ viễn thám và hệ thống thông tin địa lý (GIS) đã được ứng dụng bằng cách sử dụng ảnh THEOS để xác định vị trí và phân bố không gian khu vực nuôi cá lồng bè dựa trên phương pháp phân tích đối tượng theo hướng (OBIA).

Phosphorus, Nitrogen and Chlorophyll-A Concentrations in a Typical Dutch Polder Lake, Tjeukemeer, in Relation to its Water Regime Between 1968 and 1982

1985 ◽  
Vol 17 (4-5) ◽  
pp. 733-743 ◽  
Author(s):  
H. De Haan ◽  
J. R. Moed
Keyword(s):  
Chlorophyll A ◽  
Water Regime ◽  
Quality Standard ◽  
Summer Season ◽  
Total N ◽  
Chl A ◽  
Hydrological Data ◽  
Basic Quality ◽  
The Mean ◽  
Total P

The mean concentrations of total phosphorus (P) and total nitrogen (N) in the polder lake Tjeukemeer during the period April - September (summer season) between 1968 and 1982 were 0.215 and 3.8 mg/l, respectively. These values exceeded those laid down by the Dutch water authorities for standard water quality. Though the mean summer chlorophyll-a (chl-a) concentration of 116 µg/l during 1968 - 1982 was comparable with that for the basic quality standard, the mean concentrations between 1977 and 1982 were from 1.3 to 2.1 as high. Multiple regression analysis of the mean concentrations of total P and total N and climatological and hydrological data demonstrated that the P and N concentrations in Tjeukemeer in summer and in winter were significantly correlated with the deficit or surplus of water and consequently with the man-made regime, namely the inflow and outlet of water in SW Friesland. Between 1979 and 1982 the ratios (w/w) of the mean concentrations of total N and total P and those of particulate N and particulate P in summer were less than 16 and 10, respectively, indicating that phytoplankton growth was N rather than P limited.

scholarly journals Synergistic effects between omnivorous filter-feeding fish and nutrient enrichment on algal biomass

2015 ◽  
Vol 27 (2) ◽  
pp. 223-227 ◽  
Author(s):  
Leonardo Henrique Teixeira ◽  
José Luiz Attayde
Keyword(s):  
Chlorophyll A ◽  
Total Nitrogen ◽  
Total Phosphorus ◽  
Nutrient Enrichment ◽  
Phytoplankton Biomass ◽  
Nile Tilapia ◽  
Nutrient Addition ◽  
Northeastern Brazil ◽  
Filter Feeding ◽  
Positive Effect

Aim: The Nile tilapia - Oreochromis niloticus(Linnaeus 1758) - is an exotic omnivorous filter-feeding fish that has been stocked for three decades in man-made lakes of Northeastern Brazil. Most experiments manipulating omnivorous filter-feeding fish in eutrophic lakes and reservoirs shows that their presence tends to increase phytoplankton biomass and primary production. In this study, we tested the hypothesis that tilapia interact synergistically with nutrient enrichment so that the effects of omnivorous fish on phytoplankton biomass becomes more intense with increasing nutrient concentration.MethodsA field experiment with a 2×3 factorial design was performed during four weeks in twenty-four mesocosms (0.25 m3) to which six treatments were randomly allocated: fingerling addition (F), juvenile tilapia addition (J), nutrient addition (NP), nutrient and fingerling addition (NPF), nutrient and juvenile tilapia addition (NPJ) and a control treatment with no tilapia or nutrients addition (C). A two-way repeated measures ANOVA was done to test for time (t), tilapia and nutrients effects and their interaction on total phosphorus, total nitrogen and chlorophyll-a concentrations.ResultsThe results showed a positive effect of nutrient addition on total phosphorus, total nitrogen and chlorophyll-a concentrations and a positive effect of tilapia on the concentration of chlorophyll-a. As expected, we found a synergistic interaction between the positive effect of Nile tilapia and nutrient enrichment on phytoplankton biomass.ConclusionsThe above results suggest that controlling tilapia abundance through fisheries management is a potential tool to improve water quality and mitigate the effects of lake and reservoir eutrophication.

scholarly journals Geostatistical techniques applied to mapping limnological variables and quantify the uncertainty associated with estimates

2015 ◽  
Vol 27 (4) ◽  
pp. 421-430 ◽  
Author(s):  
Cristiano Cigagna ◽  
Daniel Marcos Bonotto ◽  
José Ricardo Sturaro ◽  
Antonio Fernando Monteiro Camargo
Keyword(s):  
Chlorophyll A ◽  
Total Nitrogen ◽  
Total Phosphorus ◽  
Statistical Technique ◽  
Random Component ◽  
Semivariogram Analysis ◽  
Uncertainty Calculation ◽  
Geostatistical Techniques ◽  
Standard Deviations ◽  
Grid Points

Abstract Aim: This study aimed to map the concentrations of limnological variables in a reservoir employing semivariogram geostatistical techniques and Kriging estimates for unsampled locations, as well as the uncertainty calculation associated with the estimates. Methods: We established twenty-seven points distributed in a regular mesh for sampling. Then it was determined the concentrations of chlorophyll-a, total nitrogen and total phosphorus. Subsequently, a spatial variability analysis was performed and the semivariogram function was modeled for all variables and the variographic mathematical models were established. The main geostatistical estimation technique was the ordinary Kriging. The work was developed with the estimate of a heavy grid points for each variables that formed the basis of the interpolated maps. Results: Through the semivariogram analysis was possible to identify the random component as not significant for the estimation process of chlorophyll-a, and as significant for total nitrogen and total phosphorus. Geostatistical maps were produced from the Kriging for each variable and the respective standard deviations of the estimates calculated. These measurements allowed us to map the concentrations of limnological variables throughout the reservoir. The calculation of standard deviations provided the quality of the estimates and, consequently, the reliability of the final product. Conclusions: The use of the Kriging statistical technique to estimate heavy mesh points associated with the error dispersion (standard deviation of the estimate), made it possible to make quality and reliable maps of the estimated variables. Concentrations of limnological variables in general were higher in the lacustrine zone and decreased towards the riverine zone. The chlorophyll-a and total nitrogen correlated comparing the grid generated by Kriging. Although the use of Kriging is more laborious compared to other interpolation methods, this technique is distinguished for its ability to minimize the variance of the estimate and provide the estimated value of the degree of uncertainty.

Nutrient retention and export to surface waters in Lithuanian and Estonian river basins

2012 ◽  
Vol 43 (4) ◽  
pp. 359-373 ◽  
Author(s):  
Arvydas Povilaitis ◽  
Per Stålnacke ◽  
Anatoly Vassiljev
Keyword(s):  
Land Use ◽  
Total Nitrogen ◽  
Total Phosphorus ◽  
Surface Waters ◽  
Nutrient Retention ◽  
Water Quality Monitoring ◽  
River Basins ◽  
Point Sources ◽  
Retention Capacity ◽  
Total N

The statistical model MESAW was applied to simultaneously estimate export coefficients and retention of nutrients in four Lithuanian and three Estonian river basins (range 946–8,388 km2). This modelling approach uses non-linear regression to yield the export coefficients for total nitrogen and total phosphorus losses to surface waters, considering different land-use classes and retention of nutrients in the river network. The model was applied to data from 40 water quality monitoring sites and corresponding sub-basin data on land use, point sources and atmospheric deposition. The results showed that the studied river basins had a high nutrient retention capacity: 67–78 and 24–63% of total nitrogen and total phosphorus inputs remained in surface waters. The estimated retention was large in lakes: 27–59% for nitrogen and 11–31% for phosphorus. In-stream retention was apparently much lower, in the range 11–15% for total N and 3–12% for total P. Retention in lakes was lower in Estonia than in Lithuania due to the locations and smaller areas of the lakes in the Estonian basins. In Estonia, the highest relative retention in lakes was 46% for nitrogen and 35% for phosphorus. In-stream retention was also somewhat lower than in Lithuania, possibly because of the lower temperature in Estonian rivers in summer.

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