scholarly journals Assessment for which tide level saltwater intrusion occurs in a sewer network. Case study: Barreiro/Moita WWTP, Portugal

2020 ◽  
Vol 15 (3) ◽  
pp. 723-733
Author(s):  
A. Figueiredo ◽  
L. Amaral ◽  
J. Pacheco
Keyword(s):  
Saltwater Intrusion ◽  
Salt Water ◽  
High Tide ◽  
Treatment Plant ◽  
Tagus Estuary ◽  
Mean Sea Level ◽  
Sewer Network ◽  
Tide Level ◽  
The Mean

Abstract Salt water from the Tagus Estuary has been identified in the influent at Barreiro/Moita Wastewater Treatment Plant (WWTP), Portugal. The saltwater intrusion occurs during high tide levels in the estuary throughout damaged sections and direct vectors in the sewer network, changing the wastewater characteristics impacting the WWTP processes. This work has designed a methodology to assess from which tide level in the Tagus Estuary saltwater intrusion occurs in the sewer network by measuring WWTP influent's electric conductivity (EC). The methodology identifies saltwater intrusion for tide levels higher than 3.10 m, increasing significantly for tide levels higher than 4.00 m. During this study, 86% of the days registered at least one high tide level higher than 3.10 m, and 8% higher than 4.00 m, demonstrating a considerable occurrence of saltwater intrusion in the system with a tendency to increase due to the mean sea level rise registered in the Tagus Estuary. To prevent it, it is necessary to map infrastructures and assess the most critical points.

scholarly journals Forecasting saltwater intrusion volume and sulfate content in a wastewater collection system. Case study: Barreiro/Moita WWTP, Portugal

2021 ◽  
Author(s):  
A. Figueiredo ◽  
L. Amaral ◽  
J. Pacheco
Keyword(s):  
Salt Water ◽  
High Tide ◽  
Treatment Plant ◽  
Strong Correlations ◽  
Collection System ◽  
Pumping Stations ◽  
Forecast Models ◽  
The Right ◽  
Wastewater Collection

Abstract The presence of salt water from the Tagus Estuary has been identified in the influent at Barreiro/Moita Wastewater Treatment Plant (WWTP), Portugal. The intrusion occurs throughout damaged sections and direct vectors in the wastewater collection system, during high tide levels, changing the wastewater characteristics and impacting the WWTP process. This study designed models to quantify this problem, enabling more effective countermeasures within the right timing. The proposed models estimate the average volume of salt water and sulfate () load for each high tide period. The laboratory results show strong correlations between the influent electrical conductivity (EC) and percentage of salt water in WWTP inflow (0.9909), and between EC and concentration in WWTP influent (0.9797). The forecast models also show good correlation between the high tide levels with volume of salt water (0.9145) and load (0.9162) entering the system. Considering the total monthly inflow, the highest percentage of salt water registered in WWTP inflow was 3.6%. During high tide periods, critical situations have been assessed with up to 53.9% of salt water in the WWTP inflow, increasing energy consumption and costs in pumping stations.

scholarly journals Analysis on the Extreme Sea Levels Changes along the Coastline of Bohai Sea, China

Atmosphere ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 324 ◽  
Author(s):  
Jianlong Feng ◽  
Delei Li ◽  
Hui Wang ◽  
Qiulin Liu ◽  
Jianli Zhang ◽  
...  
Keyword(s):  
Sea Level ◽  
Bohai Sea ◽  
High Tide ◽  
Tide Gauges ◽  
Mean Sea Level ◽  
Sea Levels ◽  
The Bohai Sea ◽  
Extreme Sea Levels ◽  
The Mean

Using hourly sea level data from four tide gauges, the changes of the extreme sea level in the Bohai Sea were analyzed in this work. Three components (i.e., mean sea level, tide and surge) as well as the tide–surge interaction were studied to find which component was important in the changes of extreme sea levels. Significant increasing trends exist in the mean sea level at four tide gauges from 1980 to 2016, and the increase rate ranges from 0.2 to 0.5 cm/year. The mean high tide levels show positive trends at four tide gauges, and the increasing rate (0.1 to 0.3 cm/year) is not small compared with the long-term trends of the mean sea levels. However, the mean tidal ranges show negative trends at Longkou, Qinhuangdao and Tanggu, with the rate from about −0.7 to −0.2 cm/year. At Qinhuangdao and Tanggu, the annual surge intensity shows explicit long-term decreasing trend. At all four tide gauges, the storm surge intensity shows distinct inter-annual variability and decadal variability. All four tide gauges show significant tide–surge interaction, the characteristics of the tide–surge interaction differ due to their locations, and no clear long-term change was found. Convincing evidence implies that the extreme sea levels increase during the past decades from 1980 to 2016 at all tide gauges, with the increasing rate differing at different percentile levels. The extreme sea level changes in the Bohai Sea are highly affected by the changes of mean sea level and high tide level, especially the latter. The surge variation contributes to the changes of extreme sea level at locations where the tide–surge interaction is relatively weak.

Evidence for a Holocene High Sea-Level Stand, Vanua Levu, Fiji

1990 ◽  
Vol 33 (3) ◽  
pp. 352-359 ◽  
Author(s):  
Takao Miyata ◽  
Yasuo Maeda ◽  
Eiji Matsumoto ◽  
Yoshiaki Matsushima ◽  
Peter Rodda ◽  
...  
Keyword(s):  
Sea Level ◽  
High Tide ◽  
Tectonic Uplift ◽  
Mean Sea Level ◽  
Southeastern Coast ◽  
Tide Level

AbstractTwo distinct elevations of emerged notches can be recognized on the southeastern coast of Vanua Levu: the higher notch is +2.22 to +3.30 m above low-tide level and the lower +1.52 to +1.65 m above low-tide level. Many emerged Holocene corals encrust higher notch floors and benches or occur as microatolls and from these radiocarbon ages ranging from 6000 to 3400 yr B.P. were obtained. The higher notches are significantly higher than present high-tide level, even allowing for relative tectonic uplift. This is supported by elevations of emerged microatolls and their 14C ages. Thus, mean sea level of the mid-Holocene was higher than that at present.

scholarly journals Saltwater Intrusion in the Upper Tagus Estuary during Droughts

Geosciences ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 400 ◽  
Author(s):  
Marta Rodrigues ◽  
André B. Fortunato ◽  
Paula Freire
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
River Discharge ◽  
Saltwater Intrusion ◽  
Tagus Estuary ◽  
Economic Sectors ◽  
Tagus River ◽  
The Mean ◽  
The Impact ◽  
Economic And Social Impacts

Droughts reduce freshwater availability and have negative environmental, economic, and social impacts. In estuaries, the dynamics between the saltwater and the freshwater can be affected during droughts, which can impact several natural resources and economic sectors negatively. The Tagus estuary is one of the largest estuaries in Europe and supports diverse uses and activities that can be affected by the saltwater intrusion (e.g., agriculture). This study assesses the saltwater intrusion in the upper reaches of the Tagus estuary using a process-based model to explore different scenarios of freshwater discharge and sea level rise. For the river discharge and mean sea level rise scenarios analyzed, salinity can reach concentrations that are inadequate for irrigation when the mean Tagus river discharge is similar or lower than the ones observed during recent droughts (22–44 m3/s). Lower river discharges aggravate the consequences. Results also show that the salinity increases with the duration of the droughts. In contrast, the impact of a moderate sea level rise on salinity intrusion is modest when compared with the impact of low river discharges. These findings contribute to support the management of the agricultural activities in the upper Tagus estuary and the water resources in the Tagus river basin.

scholarly journals Domestication, Conservation, and Livelihoods: A Case Study of Piper peepuloides Roxb.—An Important Nontimber Forest Product in South Meghalaya, Northeast India

2013 ◽  
Vol 2013 ◽  
pp. 1-7
Author(s):  
H. Tynsong ◽  
M. Dkhar ◽  
B. K. Tiwari
Keyword(s):  
Market Price ◽  
Egg Yolk ◽  
Northeast India ◽  
Market Demand ◽  
Mean Sea Level ◽  
Betel Leaf ◽  
Evergreen Forests ◽  
Nontimber Forest Product ◽  
The Mean

Wild pepper (Piper peepuloides Roxb., family: Piperaceae) is an evergreen climber which grows wild in tropical evergreen forests and subtropical evergreen forests of northeast India. This plant grows luxuriantly in the areas with high rainfall at lower elevations ranging from 100 to 800 m above mean sea level. In Meghalaya, to meet the market demand, farmers have domesticated it in arecanut agroforests and betel leaf agroforests. We found that the mean density of wild pepper in arecanut agroforest is 585 stem/ha and only 85 stem/ha in natural forest. In India, wild pepper is used in a variety of Ayurvedic medicines. Local people of Meghalaya uses powdered dry seeds mixed with honey and egg yolk for the treatment of severe cough. The study reveals that the average gross annual production of wild pepper is 7 quintals/ha, and final market price fetches Rs. 336,000/ha, out of which 42% of the money goes to the grower, 16% to local trader, 23% to dealer, 17% to retailer, 1.2% to wages of labourers, and 0.6% to transport.

Analysis and balance of phosphorous removal from wastewater at urban wastewater treatment plant

2020 ◽  
Vol 15 (2) ◽  
pp. 142-151
Author(s):  
Peter Lukac ◽  
Lubos Jurik
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Wastewater Treatment Plants ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Phosphorus Recovery ◽  
Anaerobic Sludge ◽  
Biological Phosphorus Removal ◽  
The Mean

Abstract:Phosphorus is a major substance that is needed especially for agricultural production or for the industry. At the same time it is an important component of wastewater. At present, the waste management priority is recycling and this requirement is also transferred to wastewater treatment plants. Substances in wastewater can be recovered and utilized. In Europe (in Germany and Austria already legally binding), access to phosphorus-containing sewage treatment is changing. This paper dealt with the issue of phosphorus on the sewage treatment plant in Nitra. There are several industrial areas in Nitra where record major producers in phosphorus production in sewage. The new wastewater treatment plant is built as a mechanicalbiological wastewater treatment plant with simultaneous nitrification and denitrification, sludge regeneration, an anaerobic zone for biological phosphorus removal at the beginning of the process and chemical phosphorus precipitation. The sludge management is anaerobic sludge stabilization with heating and mechanical dewatering of stabilized sludge and gas management. The aim of the work was to document the phosphorus balance in all parts of the wastewater treatment plant - from the inflow of raw water to the outflow of purified water and the production of excess sludge. Balancing quantities in the wastewater treatment plant treatment processes provide information where efficient phosphorus recovery could be possible. The mean daily value of P tot is approximately 122.3 kg/day of these two sources. The mean daily value of P tot is approximately 122.3 kg/day of these two sources. There are also two outflows - drainage of cleaned water to the recipient - the river Nitra - 9.9 kg Ptot/day and Ptot content in sewage sludge - about 120.3 kg Ptot/day - total 130.2 kg Ptot/day.

Side effects of cultured bacteria addition in wastewater collection system on plant operations – a case study

2012 ◽  
Vol 7 (1) ◽  
Author(s):  
Yanjin Liu ◽  
Giraldo Eugenio
Keyword(s):  
Energy Use ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Collection System ◽  
Oil And Grease ◽  
Odor Control ◽  
Plant Operations ◽  
Cultured Bacteria ◽  
Wastewater Collection

Cultured bacteria addition is one of the technologies used for odor control and FOG (fat, oil, and grease) removal in wastewater collection systems. This study investigated the efficiency of bacterial addition on wastewater odor control by conducting a set of full scale trials in a 60,000 cubic meter per day system for a period of two years. The objectives of this study were: (i) to identify factors that could impact wastewater treatment plant (WWTP) operations due to the effect of bacterial addition in the collection system, (ii) to estimate/understand the level of those impacts, and (iii) to present some interesting findings from the completed case study. The plant operation data before and during the bacterial addition were reviewed. The application of the cultured bacteria presented in the study was found to have significant impacts on the operation of the WWTP in terms of influent biological oxygen demand (BOD) and total suspended solids (TSS) loading, primary settling, sludge production, energy use, dissolved sulfides concentration, and methane production.

The Implementation of Biological Phosphorus and Nitrogen Removal with the Bio-Denipho Process on a 265,000 PE Treatment Plant

1992 ◽  
Vol 25 (4-5) ◽  
pp. 161-168 ◽  
Author(s):  
J. Einfeldt
Keyword(s):  
Nitrogen Removal ◽  
Treatment Plant ◽  
First Year ◽  
In Series ◽  
Design Loads ◽  
Last Stage ◽  
Two Stages ◽  
The City ◽  
Biological Phosphorus

A process, called Bio-Denipho, for combined biological phosphorus and nitrogen removal in a combination of an anaerobic tank and two oxidation ditches is described. In this process the anaerobic tank consisting of three sections working in series is followed by two oxidation ditches. These too are working in series, but with both inlet to and outlet from the tanks changing in a cycle. The Bio-Denipho process is described specifically for the process itself and as a case study for the implementation of the process on a 265,000 pe wastewater treatment plant for the city of Aalborg in Denmark. The plant was designed and erected in two stages and the last stage was inaugurated October 31,1989. Lay-out and functions for the plant is described and design loads, plan lay-out and tank volumes are given in this paper together with performance data for the first year in operation.

NODAL CYCLE, QUASI-LUNAR CYCLE, AND FLORIDA CURRENT INFLUENCES ON HIGH TIDE LEVEL IN MIAMI FLORIDA

2020 ◽  
Author(s):  
Martina Rogers ◽  
◽  
Michael C. Sukop ◽  
Jayantha Obeysekera ◽  
Florence George ◽  
...  
Keyword(s):  
High Tide ◽  
Lunar Cycle ◽  
Florida Current ◽  
Tide Level
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