scholarly journals Worms and submersed macrophytes reduce methane release and increase nutrient removal in organic sediments

2021 ◽  
Author(s):  
Sara Benelli ◽  
Marco Bartoli
Keyword(s):  
Nutrient Removal ◽  
Submersed Macrophytes ◽  
Methane Release ◽  
Organic Sediments

Stabilizing pyritic material

1989 ◽  
Vol 4 ◽  
pp. 244-248 ◽  
Author(s):  
Donald L. Wolberg
Keyword(s):  
Significant Contribution ◽  
Organic Materials ◽  
Sedimentary Rocks ◽  
Iron Sulfides ◽  
Decomposition Products ◽  
Iron Minerals ◽  
Pyrite Formation ◽  
Organic Sediments ◽  
Freshwater Environments

The minerals pyrite and marcasite (broadly termed pyritic minerals) are iron sulfides that are common if not ubiquitous in sedimentary rocks, especially in association with organic materials (Berner, 1970). In most marine sedimentary associations, pyrite and marcasite are associated with organic sediments rich in dissolved sulfate and iron minerals. Because of the rapid consumption of sulfate in freshwater environments, however, pyrite formation is more restricted in nonmarine sediments (Berner, 1983). The origin of the sulfur in nonmarine environments must lie within pre-existing rocks or volcanic detritus; a relatively small, but significant contribution may derive from plant and animal decomposition products.

The invisible BNR plant provides high quality effluent and recreational area for densely populated urban area

2009 ◽  
Vol 4 (1) ◽  
Author(s):  
E. Choi ◽  
Z. Yun ◽  
K.S. Min
Keyword(s):  
Nutrient Removal ◽  
Operating Temperature ◽  
Treatment Plant ◽  
Ground Level ◽  
Biological Nutrient Removal ◽  
High Quality ◽  
Sand Filter ◽  
Sport Facilities ◽  
Final Effluent ◽  
Removal System

In a densely populated area, a large wastewater treatment plant (WWTP) has been constructed in the underground. The plant is practically “invisible” to visitors and neighbours, and the ground level is used as a park and sport facilities in order to avoid the “not in my backyard” phenomenon. The WWTP has a 5-stage biological nutrient removal system utilizing the denitrifying PAO (dPAO) with a step feed in order to treat the weak sewage with higher nutrient removal requirement. Although the underground installation could be expected to increase plant operating temperature, the temperature increase was only 1°C. The polished final effluent from a sand filter produced average TN and TP concentrations of 5.11 mg/L and 0.91 mg/L, respectively with SS concentrations of 0.61 mg/L, indicating that the dPAO system combined with sand filter effectively produced a high quality effluent.

Examples for the Upgrading of Existing Activated Sludge Plants for Nutrient Removal

1990 ◽  
Vol 22 (7-8) ◽  
pp. 113-121
Author(s):  
W. Maier
Keyword(s):  
Activated Sludge ◽  
Nutrient Removal ◽  
Sewage Treatment ◽  
West Germany ◽  
Sewage Treatment Plants ◽  
Effluent Standards ◽  
Near Future

In view of the new effluent standards in West Germany, including nitrification and phosphorus elimination, many of the existing sewage treatment plants will have to be rebuilt or expanded. Another demand which will have to be dealt with in the near future is denitrification. Under consideration of the large BOD5-loads which were taken into account when designing the plants, many of them nitrify during the summer or can be easily converted to operate with nitrification. Principles for planning the upgrading of such plants have been laid down in order to achieve the required effluent concentrations. The application of these principles is demonstrated with examples of upgraded plants.

Upgrading Wastewater Treatment Plants for Biological Nutrient Removal

1990 ◽  
Vol 22 (7-8) ◽  
pp. 53-60 ◽  
Author(s):  
B. Rabinowitz ◽  
T. D. Vassos ◽  
R. N. Dawson ◽  
W. K. Oldham
Keyword(s):  
Wastewater Treatment ◽  
Nutrient Removal ◽  
Wastewater Treatment Plants ◽  
Design Flow ◽  
Biological Nutrient Removal ◽  
Nitrogen And Phosphorus ◽  
Conventional Activated Sludge ◽  
Recent Developments ◽  
Removal Technology ◽  
Biological Nitrogen

A brief review of recent developments in biological nitrogen and phosphorus removal technology is presented. Guidelines are outlined of how current understanding of these two removal mechanisms can be applied in the upgrading of existing wastewater treatment plants for biological nutrient removal. A case history dealing with the upgrading of the conventional activated sludge process located at Penticton, British Columbia, to a biological nutrient removal facility with a design flow of 18,200 m3/day (4.0 IMGD) is presented as a design example. Process components requiring major modification were the headworks, bioreactors and sludge handling facilities.

Optimization of Nutrient Removal in Stockholm

1991 ◽  
Vol 24 (7) ◽  
pp. 103-111 ◽  
Author(s):  
G. Brattberg ◽  
L.-G. Reinius ◽  
M. Tendaj
Keyword(s):  
Nutrient Removal ◽  
Sewage Treatment ◽  
Water Source ◽  
Chemical Precipitation ◽  
Phosphorus Load ◽  
Sewage Treatment Plants ◽  
Limiting Nutrient ◽  
Baltic Proper ◽  
Mechanical Stage ◽  
The Baltic

Stockholm was founded at the point where the waters of Lake Mälaren emerge into the Baltic Sea. Lake Mälaren is the water source of the water works of Stockholm. The Lake also receives water from one of the sewage treatment plants. The outlet from the two other sewage treatment plants are in the inner part of the archipelago. During 1968-73 the treatment was improved, after which the phosphorus load to the receiving water significantly decreased. The total P concentration in the surface water has decreased since 1970 and phosphorus has replaced nitrogen as the most limiting nutrient throughout the entire archipelago within 50 km from Stockholm. To further reduce the eutrophication a continued reduction of the phosphorus load is most effective. For the Baltic proper as a whole, where primary nitrogen limitation is present, it is important to reduce the supply of nitrogen to the greatest possible extent. The treatment plants in Stockholm are located in subsurface rock-chambers. The treatment includes mechanical, biological and chemical treatment. In the mechanical stage the sewage is treated in screens, grit chambers and primary sedimentation. The biological stage is a conventional activated sludgeprocess. For the chemical precipitation ferroussulphateis added before the screens. The sludge is stabilized in anaerobic digesters and dewatered in centrifuges before disposal on farmland. To meet more stringent requirements on nitrification and nitrogen removal several projects are going on to optimize the nutrient removal. The aim of these investigations is to improve the plants' performance within the existing plant.

Nutrient Removal in Small Wastewater Treatment Plants

1990 ◽  
Vol 22 (3-4) ◽  
pp. 211-216
Author(s):  
Niels Skov Olesen
Keyword(s):  
Wastewater Treatment ◽  
Nitrogen Removal ◽  
Nutrient Removal ◽  
Phosphorus Removal ◽  
Wastewater Treatment Plants ◽  
Ferrous Sulphate ◽  
Practical Solution ◽  
Sensitive Technique ◽  
Pumping Station ◽  
Denitrification Reactor

In some areas of Denmark nutrient removal is required even for very small wastewater plants, that is down to 500 pe (pe = person equivalents). The goal for the removal is 80% removal of nitrogen and 90% removal of phosphorus, or in terms of concentrations: 8 mg nitrogen/l and 1.2 mg phosphorus/l. The inlet concentrations are typically 40 mg N/l and 10 mg P/l. The paper presents the results from two such plants with a capacity of 800 pe. Phosphorus removal is made by simultaneous precipitation with ferrous sulphate. Nitrogen removal is carried out using the recirculation method. Both plants were originally rotor aerated oxidation ditches. They have been extended with a denitrification reactor and a recirculation pumping station. At present both plants have been in activity for about 3 years and with satisfactory results. Average concentrations of nitrogen (summer) and phosphorus is 7 mg/l and 0.9 mg/l respectively. Nitrogen removal seems to be a practical solution on these small plants. It is,though, sensitive to temperature and highly oxidized rain water. Phosphorus removal seems to be an easily run and relatively non-sensitive technique at least when using simultaneous precipitation.

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