scholarly journals Preliminary hydrochemical characteristics of an urban lake restored using a sequential application of iron and aluminum coagulants

2021 ◽  
Vol 21 (2) ◽  
pp. 81-88
Author(s):  
Anna Płachta
Keyword(s):  
Chlorophyll A ◽  
Total Concentration ◽  
Nutrient Concentrations ◽  
Hydrochemical Characteristics ◽  
High Concentration ◽  
Summer Period ◽  
Nitrogen And Phosphorus ◽  
Low Visibility ◽  
Phosphorus Inactivation ◽  
The Impact

Abstract A study was carried out on Lake Mielenko in Kartuzy. It is a small and shallow waterbody (7.8 ha, max. depth 1.8 m), whose morphometric conditions qualify it as a polymictic lake (the first lake in a river - lake system). Before the reclamation began, the lake was characterized by a high concentration of chlorophyll-a (16.4 mg m−3 in spring to 33 mg m−3 in summer) and low visibility. The purpose of the study was to determine the impact of the first stage of restoration of Lake Mielenko by phosphorus inactivation using a combination of aluminum and iron coagulants (PIX and PAX). After coagulant dosing into the lake, a significant decrease in chlorophyll-a was observed, which resulted in improving water transparency in the lake and decreasing concentrations of both nutrients (nitrogen and phosphorus). The total concentration of nutrients was dominated by organic forms (constituting 71-95%). Maximum nutrient concentrations were 0.273±0.01 mg P L−1 and 5.52±0.1 mg N L-1 (in the summer period before the restoration activities were performed).

The use of artificial oxygenation to reduce nutrient availability in the Canning River, Western Australia

2001 ◽  
Vol 43 (9) ◽  
pp. 133-144 ◽  
Author(s):  
B. Greenop ◽  
K. Lovatt ◽  
M. Robb
Keyword(s):  
Dissolved Oxygen ◽  
Water Column ◽  
Western Australia ◽  
Algal Blooms ◽  
Positive Impact ◽  
Monitoring Program ◽  
Nutrient Concentrations ◽  
Nitrogen And Phosphorus ◽  
The Impact ◽  
Oxygen Concentrations

Artificial oxygenation has been used for two summer periods to improve the water quality of the Canning River in Perth, Western Australia. The project is part of the Swan Canning Cleanup Program, which aims to reduce the frequency and severity of nuisance and toxic algal blooms in the Swan-Canning estuary. The trials have proved that oxygenation has increased the dissolved oxygen concentrations in the water column, particularly in the bottom waters where dissolved oxygen concentrations are frequently below a critical level of three milligrams per litre. Oxygenation has had a positive impact on nutrient concentrations in the water column and nitrogen cycling processes. Reductions in nutrient concentrations were highlighted by drops in ammonium and total phosphorus concentrations of 97% and 64% following the recommencement of oxygenation after a plant shutdown. Results of a microbiological study combined with the data analysis indicate that the number of nitrifying microbes have increased due to oxygenation. However, comparisons between oxygenated and control areas were inconclusive about the ability of the oxygenation plant to reduce total nitrogen and phosphorus levels. This could be explained by factors such as spatial variability, water flow during the trials and measurement limitations in the monitoring program. Future work will concentrate on assessing the impact of the oxygenation plant on nutrient concentrations.

Monitoring Effects of Drought on Nitrogen and Phosphorus in Temperate Oak Forests Using Machine Learning Techniques

2018 ◽  
Author(s):  
Jan Kotlarz ◽  
Katarzyna Kubiak ◽  
Marcin Spiralski
Keyword(s):  
Machine Learning ◽  
Drought Stress ◽  
Negative Impact ◽  
Aerial Images ◽  
Machine Learning Techniques ◽  
Nutrient Concentrations ◽  
Nitrogen And Phosphorus ◽  
Learning Techniques ◽  
The Impact

Oak is a European tree species highly sensitive to drought. If declining symptoms appear they are often detectable at the crown (such as dieback) enabling monitoring using aerial images and remote sensing methods. Here, we analyzed the impact of short and long-term drought on oaks located in central Poland, between the years of 2014 and 2017. We used leaf nitrogen (N) and phosphorus (P) concentrations measured in the laboratory, aerial images collected in the range of 460-880 nm and machine learning techniques to estimate nutrient concentrations on the > 4000 oaks growing on gleysoil in the study area. We determined a negative impact on N and P concentrations during both types of drought stress (-23% and 19% for N concentration in leaves; -27% and -10% for P concentration in leaves) and an inconsiderable impact on N:P values (3% increase of N:P ration during short and 7% decrease of N:P ration during long-term drought stress). We found that the long-term drought impact was spatially diverse, possibly depending on the presence of drainage ditches and competing species.

Gas Exchange Characters with SO2 Fumigation of Different Concentration and Time in Soybean

2012 ◽  
Vol 518-523 ◽  
pp. 5450-5454
Author(s):  
Jing Li ◽  
Da Long Jiang ◽  
Xiao Ming Li
Keyword(s):  
Gas Exchange ◽  
Chlorophyll A ◽  
Photosynthetic Rate ◽  
Crop Production ◽  
Photosynthetic Activity ◽  
High Concentration ◽  
Low Concentration ◽  
Long Time ◽  
Short Time ◽  
The Impact

The low concentration of SO2 in the air can promote stomata opening of plants and improving plant photosynthetic rate, but the gradual accumulation of SO2 on plant leaves can convert the chlorophyll into phaeophytin, which has no photosynthetic activity, and then affect the plant growth and crop production. After Fumigation with SO2 in soybean under several different concentrations (4 µl/l,10 µl/l,20 µl/l,40 µl/l) and time spans(1h,2h,4h) respectively, the photosynthesis and gas exchange characteristics were determined. The experimental data showed: (1) with the increasing of concentration and time for fumigation, SO2 had a great adverse effect on photosynthesis in soybean. Such as the light saturation point of plants decreased, the light compensation point increased, and the maximum net photosynthetic rate reduced significantly (e.g., fumigation with SO2,4-40 µl/l-4 h, Anmax reduced 29.5% to control) compared with the control plants’. (2)After all kinds processing time, low concentration of fumigation (4µl/l) caused larger stomatal conductance than control. However, the other treatments caused smaller gs than control. (3)gs revealed significant positive correlation with transpiration rate(E), each treatment and control shows r ≥0.9,P2. (5)Concentration of chlorophyll was no insignificant differences with the control at different treatments. After fumigation, the range of chlorophyll a / b was 1.39~1.61 and there was no big difference from control (chlorophyll a / b is 1.49), except the treatment of 20µl/l-1h, which had a significant decline in chlorophyll b (chlorophyll a / b is 1.71).Results: (1) SO2 concentration had greater impact on soybean than time of fumigation, and the impact of high concentration in short time on soybean was obviously significant. (2) SO2 fumigation in short time and low concentration can promote stomata open, however SO2 also can damage the photosynthetic activity of chlorophyll. After a long time of fumigation, photosynthetic rate decreased rapidly, even if gs increased.

Changes in nutrient levels in some Eastern European rivers in response to large-scale changes in agriculture

2004 ◽  
Vol 49 (3) ◽  
pp. 29-36 ◽  
Author(s):  
P. Stålnacke ◽  
S.M. Vandsemb ◽  
A. Vassiljev ◽  
A. Grimvall ◽  
G. Jolankai
Keyword(s):  
Time Series ◽  
Large Scale ◽  
Agricultural Land ◽  
Nutrient Concentrations ◽  
Similar Data ◽  
Eastern European ◽  
Nutrient Inputs ◽  
Nitrogen And Phosphorus ◽  
Catchment Areas ◽  
The Impact

Since the late 1980s, the use of commercial fertilisers in most Eastern European countries has decreased at an unprecedented rate. We examined the impact of this dramatic reduction in agricultural inputs on concentrations of nutrients in four rivers in Eastern Europe: the Emajogi and Õhnejogi (Estonia), the Daugava (Latvia), and the Tisza (Hungary). Time series of nitrate (NO3-N) and phosphate (PO4-P) concentrations and data on runoff were selected to represent catchments with substantial areas of agricultural land and available time series of sufficient length and frequency. The study period was 1987-1998. We detected downward trends in nitrate-N and phosphate-P in only two of the four rivers. Our results imply that the response to the extensive decrease in agricultural intensity since the late 1980s has been slow and limited in many rivers. Corresponding results in the literature are inconclusive and comprise several examples of both decreasing and non-decreasing nutrient concentrations. Our findings, along with similar data from other studies, indicate that large cuts in nutrient inputs do not necessarily induce an immediate response, particularly in medium-sized and large catchment areas. Moreover, the difference we noted between nitrogen and phosphorus suggests that factors other than reduced fertiliser application influenced the inertia of the water quality response.

scholarly journals Modeling and Monitoring of Hydrodynamics and Surface Water Quality in the Sulejów Dam Reservoir, Poland

Water ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 296
Author(s):  
Aleksandra Ziemińska-Stolarska ◽  
Magdalena Kempa
Keyword(s):  
Water Quality ◽  
Chlorophyll A ◽  
Hydrodynamic Model ◽  
Total Error ◽  
Maximum Growth ◽  
Environmental Modeling ◽  
Nutrient Concentrations ◽  
Quality Model ◽  
High Concentration ◽  
Measured Velocity

The aim of this work is to evaluate core variables of the ecological potential of the Sulejów Reservoir (temperature distribution, flow velocities, and concentrations of selected indicators, e.g., phosphates, nitrates, the abundance of phytoplankton) using a three-dimensional hydrodynamic model, GEMSS-HDM (generalized environmental modeling system for surface waters), coupled with a water quality model, WASP EUTRO (GEMSS-WQM). The monitoring data necessary to build the model were obtained from two multiparameter probes that were submerged in two locations in the Sulejów Reservoir. An ADCP current profiler was used to collect data for hydrodynamic model calibration and verification. Total error between computed and measured velocity was estimated at 10–15%. A high concentration of chlorophyll-a during the vegetation season of 2015 (0.02 mg/L) was coupled with high water temperature (above 25 °C) and low concentrations of biogenic compounds (phosphorus and nitrogen at 0.02 and 0.001 mg/L, respectively). In 2015, NO3-N was the limiting nutrient in the Sulejów Reservoir. Maximum growth of algae was observed in June and July 2015 (0.02 mg/L chla) along the entire length of the reservoir; algae bloom volume reduction was observed in September (0.004 mg/L chla). Proposed scenarios for nutrient reduction—50% reduction of phosphate-phosphorus (PO4-P) and nitrate-nitrogen (NO3-N) from agriculture areas as well as 50% reduction of discharges from septic tanks—led to a considerable reduction of nutrient concentrations in the reservoir waters; it additionally favors reducing the concentration of chlorophyll-a. The obtained results indicate that these sources of pollutants are mainly responsible for the poor water quality status of the reservoir and more intensive eutrophication phenomena.

scholarly journals Impact of maintenance of Macrobrachium rosenbergii De Man, 1879 (Crustacea, Decapoda, Palaemonidae) broodstock on the water used in culture ponds

2011 ◽  
Vol 71 (4) ◽  
pp. 857-863 ◽  
Author(s):  
JFV. Biudes ◽  
AFM. Camargo ◽  
MNP. Henares
Keyword(s):  
Chlorophyll A ◽  
Inorganic Nitrogen ◽  
Macrobrachium Rosenbergii ◽  
Economic Benefits ◽  
Effluent Water ◽  
Nitrogen And Phosphorus ◽  
Dissolved Phosphorus ◽  
Physical And Chemical ◽  
The Impact ◽  
Kjeldahl Nitrogen

Aquaculture production generates social and economic benefits, but can also cause environmental impacts. The objectives of this study were: a) to characterise the impacts caused by the maintenance of broodstock of the giant river prawn (Macrobrachium rosenbergii) on the physical and chemical characteristics of the water used in culture ponds, and b) to evaluate the relationship between the biomass of the prawns and the impact of culture on the water used in the ponds. Between January and December 2004, we determined, monthly, the biomass of M. rosenbergii by means of biometrics, and the physical and chemical variables of the supply and effluent water from a pond used to maintain breeding stock. The results showed that the effluent water had higher contents of chlorophyll-a, suspended particulate matter (SPM), pH, dissolved oxygen, total Kjeldahl nitrogen (TKN) and dissolved Kjeldahl nitrogen (DKN), inorganic nitrogen (IN), total (TP) and dissolved phosphorus (DP), and P-orthophosphate than the supply water. The highest biomass of M. rosenbergii occurred in April (127.0 g.m-2) and the lowest in August (71.5 g.m-2), and there were positive linear correlations between the biomass of the prawns and the intensity of the increases in TKN, DKN, IN, TP, and DP of the water used in the pond. The maintenance of broodstock of M. rosenbergii increased the chlorophyll-a, SPM, nitrogen, and phosphorus contents of the water in the pond. Additionally, the increase in the biomass of the prawns intensifies the export of nitrogen and phosphorus from the pond in the effluent.

The Puck Bay as an example of deep dredging unfavorably affecting the aquatic environment

2009 ◽  
Vol 38 (2) ◽  
Author(s):  
Bożena Graca
Keyword(s):  
Biomass Production ◽  
Aquatic Environment ◽  
Phosphorus Release ◽  
Geochemical Data ◽  
Nutrient Concentrations ◽  
Nitrogen And Phosphorus ◽  
Baltic Coast ◽  
Chemical Conditions ◽  
The Impact ◽  
Puck Bay

The Puck Bay as an example of deep dredging unfavorably affecting the aquatic environmentThe presented study is a review of available geochemical data concerning a dredge area in the Puck Bay. It is a small, semi-closed and degraded water body on the Polish Baltic coast. In this region very deep dredging was conducted in the years 1989-95. Five dredge pits were created in the bottom of the bay. Only two of them have been geochemically investigated so far. In the deepwater parts of both the dredge pits organic matter accumulation resulted in sulfate reduction and subsequent hydrogen sulfide production in the sediment, as well as elevated nutrient concentrations in the interstitial waters. Moreover, temporal oxygen deficits in the near bottom waters were observed. Such conditions favor nitrogen and phosphorus release to the water column and potentially enhance the eutrophication. The impact of deep dredging on the chemical conditions in the dredged area seems to be controlled by a complex interplay of the season, phytoplankton biomass production and hydrodynamic conditions. Areas with high biomass production and low water dynamic are probably more vulnerable to environmental degradation due to deep dredging. This implies that some of the dredge pits require different methods of recultivation than others. However the decision if, and with which methods, to remediate dredge pits in the Puck Bay requires successive research including all the pits in all four seasons.

Unifying Nutrient–Chlorophyll Relationships in Lakes

1989 ◽  
Vol 46 (7) ◽  
pp. 1176-1182 ◽  
Author(s):  
Yves T. Prairie ◽  
Carlos M. Duarte ◽  
Jacob Kalff
Keyword(s):  
Nutrient Limitation ◽  
Chlorophyll A ◽  
Nutrient Concentrations ◽  
Regression Equations ◽  
Independent Data ◽  
Nitrogen And Phosphorus ◽  
Nutrient Levels ◽  
Tn:Tp Ratio ◽  
Over Time

We used data drawn from the literature to test some basic predictions derived from nutrient limitation theory. Contrary to expectation, nitrogen was not better correlated to chlorophyll in nitrogen limited lakes (as measured by the total nitrogen:total phosphorus (TN:TP) ratio). We also examined whether the variability in published relationships between chlorophyll a (Chla) and nutrient levels in lakes can be explained by differences in the relative concentrations of nitrogen and phosphorus (TN:TP ratio). Our results show that the coefficients and precision of the Chla = f(TP) and Chla = f(TN) regression equations vary systematically and concomitantly with TN:TP ratios, and are highest for lakes with TN:TP ratios of 23–28 (by weight). These findings were confirmed with independent data and explain the variability of published Chla = f(TP) relationships. We propose a model that predicts the coefficients of Chla = f(TP) and Chla = f(TN) equations for lakes with different TN:TP ratios. This model proved useful in predicting the chlorophyll trajectories of lakes over time. The results imply an "optimal" TN:TP ratio beyond which the relative rates of increase in chlorophyll with increasing nutrient concentrations are reduced.

Vertical Fine Structure of Particulate Matter and Nutrients in Sea Ice of the High Arctic

1990 ◽  
Vol 47 (7) ◽  
pp. 1348-1355 ◽  
Author(s):  
Ralph E. H. Smith ◽  
W. Glen Harrison ◽  
Leslie R. Harris ◽  
Alex W. Herman
Keyword(s):  
Fine Structure ◽  
Particulate Matter ◽  
Sea Ice ◽  
Chlorophyll A ◽  
Light Availability ◽  
High Arctic ◽  
Inorganic Nutrient ◽  
Nutrient Concentrations ◽  
Ice Algae ◽  
Nitrogen And Phosphorus

The vertical fine structure of particulate matter and inorganic nutrients through the bottom layers of sea ice was determined at a site in the Canadian high arctic. Intense vertical gradients of chlorophyll a, nitrate, ammonium, nitrite, phosphate, and silicate developed in the lower 6 cm of the ice as ice algae attained standing crops of 250 mg∙m−2 (up to 60 mg∙L−1) of chlorophyll a. Pigment and inorganic nutrient concentrations were closely correlated, and pools of inorganic nutrient were shown to exist in the particulate matter, suggesting that the extremely high dissolved nutrient concentrations in the bottom ice (e.g. up to 400 μmol∙L−1 nitrate) were derived at least in part from leakage of algal intracellular pools. Nitrogen and phosphorus were present in excess of algal needs, but silicon may not have been. The ratios of particulate organic carbon to chlorophyll a and to particulate organic nitrogen increased from the ice–water interface upwards, consistent with a physiological response of the ice algae to the strong corresponding gradient of light availability. Although spatially compact, the assemblage of algae in the bottom ice inhabits a highly stratified environment.

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