scholarly journals Impact of River Damming on Downstream Hydrology and Hydrochemistry: The Case of Lower Nestos River Catchment (NE. Greece)

Water ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 2832
Author(s):  
Nikolaos Kamidis ◽  
Emmanuil Koutrakis ◽  
Argyrios Sapounidis ◽  
Georgios Sylaios
Keyword(s):  
Inorganic Nitrogen ◽  
Bottom Layer ◽  
Buffer Zone ◽  
N:P Ratio ◽  
Inorganic Phosphorus ◽  
Water Release ◽  
Field Surveys ◽  
Nestos River ◽  
Hydropower Dams ◽  
Almost All

In this paper, a series of field surveys were carried out along the Nestos River watershed (NE Greece) to assess the influence of two hydropower dams (Thissavros and Platanovrisi) upon the hydrology, hydrochemistry and nutrients stoichiometry of the river. Results showed that Nestos hydrology, downstream of the reservoirs, is entirely governed by the man-induced hydropower-driven dam retention/release policy. Dams’ operation increased the retention of dissolved inorganic nitrogen (DIN) and total suspended solids (TSS) significantly, affecting their downstream fluxes, even under water release regime. On the contrary, dams’ construction and operation did not seem to influence the downstream fluxes of dissolved inorganic phosphorus (DIP) and silica (DSi), although these elements also depended on the releasing policy. DIN retention, combined with the dependence of DIP to the water level of Thissavros, resulted in alteration of the N:P ratio at the downstream part. Almost all nutrients were stored at the bottom layer of Thissavros reservoir, especially under the summer stratification regime. Platanovrisi reservoir acts as a buffer zone between Thissavros and the Nestos downstream part. Anoxic conditions in the reservoirs favour the transformation of nitrates into ammonia and the remineralization of phosphorus from sediments, creating a degraded environment for freshwater fauna.

scholarly journals INFLUENCE OF STRONG MONSOON-DOMINATED CLIMATE ON BIOGEOCHEMISTRY OF THE HEAVILY ANTHROPOGENIC IMPACTED BRANTAS RIVER ESTUARIES AND MADURA STRAIT COASTAL WATER, EAST JAVA, INDONESIA

2015 ◽  
Vol 36 (2) ◽  
pp. 37-49
Author(s):  
M.S. Nugrahadi
Keyword(s):  
River Basin ◽  
Coastal Water ◽  
Inorganic Nitrogen ◽  
N:P Ratio ◽  
Inorganic Phosphorus ◽  
Dry Season ◽  
Mixing Zone ◽  
Populated Area ◽  
Chl A ◽  
Agriculture Industry

Brantas River basin and Madura Strait in East Java Indonesia, are subject to heavily change in land use and land cover, and Brantas River Basin is a very important densely populated area in East Java, Indonesia for agriculture, industry as well as for settlement. The aim of the research is to elucidate the fate of transformation of bio-elements (organic carbon, Nitrogen (N), Phosphorus (P), and Silicate (Si)) and its seasonal variability. The contrast river discharge combined with tide generates the distinctive mixing zone during rainy and dry season. Dissolved Inorganic Nitrogen (DIN) and Dissolved Inorganic Phosphorus (DIP) concentrations in the river are high and decrease to the very low value seaward. N:P ratio has seasonal variation due to large discrepancy of DIN and DIP supply from land to the sea. Dissolved Inorganic Silicate (DSi) in river and estuaries is extremely higher than the average in the world (> 150 mM). Chlorophyll-a (Chl-a) in dry season in the coastal water is higher than the rainy season. Due to high Total Suspended Matter (TSM), the primary production is limited by the light in the coastal water.

scholarly journals TESTING OF CHLORELLA/SCENEDESMUS MICROALGAE CONSORTIA FOR REMEDIATION OF WASTEWATER, CO₂ MITIGATION AND ALGAE BIOMASS FEASIBILITY FOR LIPID PRODUCTION

2014 ◽  
Vol 22 (2) ◽  
pp. 105-114 ◽  
Author(s):  
Judita Koreivienė ◽  
Robertas Valčiukas ◽  
Jūratė Karosienė ◽  
Pranas Baltrėnas
Keyword(s):  
Municipal Wastewater ◽  
Global Climate ◽  
Inorganic Nitrogen ◽  
Lipid Production ◽  
Single Species ◽  
Inorganic Phosphorus ◽  
Climatic Conditions ◽  
Biofuel Production ◽  
Treated Wastewater ◽  
Algae Biomass

Industry, transport and unsustainable agriculture result in the increased quantity of wastewater, release of nutrients and emission of carbon dioxide that promotes eutrophication of water bodies and global climate change. the application of microalgae for phycoremediation, their biomass use for human needs may increase sustainability and have a positive effect on the regional development. The experiments were carried out in order to establish the feasibility of treating the local municipal wastewater with microalgae consortia and their biomass potential for biofuel production. The results revealed that Chlorella/Scenedesmus consortium eliminated up to 99.7–99.9% of inorganic phosphorus and up to 88.6–96.4% of inorganic nitrogen from the wastewater within three weeks. The ammonium removal was more efficient than that of nitrate. Chlorella algae grew better in diluted, while Scenedesmus – in the concentrated wastewater. The consortium treated wastewater more efficiently than a single species. The maximum biomass (3.04 g/L) of algal consortium was estimated in concentrated wastewater. Algae accumulated 0.65–1.37 g of CO2/L per day in their biomass. Tus, Chlorella/Scenedesmus consortium is a promising tool for nutrients elimination from the local wastewater under the climatic conditions specific to Lithuania. However, none of the two species were able to accumulate lipids under the nitrogen starvation conditions.

scholarly journals Bathymetric surveys of Shpilje reservoir

2018 ◽  
Vol 16 (1) ◽  
pp. 149-157
Author(s):  
Dragan Ivanoski ◽  
Slavisa Trajkovic ◽  
Milan Gocic
Keyword(s):  
High Quality ◽  
Field Surveys ◽  
Republic Of Macedonia ◽  
Artificial Lakes ◽  
The Republic ◽  
Almost All ◽  
Basin Area ◽  
Regular Practice

Periodic bathymetric surveys are carried out to define quantity of sedimented material in reservoirs, as well as to determine the areas most endangered by the silting process. Such surveys in the Republic of Macedonia were started as an obligatory and regular practice in the seventies of the last century, immediately after the formation of the larger artificial lakes. These were carried out for almost all reservoirs in the country and it can be said that there is already a sufficient amount of data on some of them that can serve as a basis for high quality analyses of the silting trend of the reservoirs and of the extent to which erosion is affecting the basin area. This paper provides a review of the results from the latest field surveys and analyses of changes in the configuration of the Shpilje reservoir bottom, carried out in the period 2014 to 2016.

Changes in waste stabilisation pond performance resulting from the retrofit of activated sludge treatment upstream: part I – water quality issues

2005 ◽  
Vol 51 (12) ◽  
pp. 11-16 ◽  
Author(s):  
N.J. Cromar ◽  
D.G. Sweeney ◽  
M.J. O'Brien ◽  
H.J. Fallowfield
Keyword(s):  
Water Quality ◽  
Dissolved Oxygen ◽  
Activated Sludge ◽  
Algal Biomass ◽  
Inorganic Nitrogen ◽  
Treatment Plant ◽  
South Australia ◽  
N:P Ratio ◽  
Waste Stabilisation Ponds ◽  
Trickling Filters

This paper describes changes in effluent quality occurring before and after an upgrade to the Bolivar Wastewater Treatment Plant in South Australia. Trickling filters (TF) were replaced with an activated sludge (AS) plant, prior to tertiary treatment using waste stabilisation ponds (WSPs). The water quality in the WSPs following the upgrade was significantly improved. Reductions in total and soluble BOD, COD, TKN, suspended solids and organic nitrogen were recorded and the predominant form of inorganic nitrogen changed from NH4-N to NO2/NO3-N. The reduction in ammonium and potentially toxic free ammonia removed a control upon the growth of zooplankton, which may have contributed to decreases in algal biomass in the final ponds and consequently lower dissolved oxygen. Additionally, changes in inorganic nitrogen speciation contributed to a slightly elevated pH which reduced numbers of faecal coliforms in WSPs. The AS pretreated influent recorded significantly lower inorganic molar N:P ratio (10–4:1) compared to those fed with TF effluent (17–13:1). Algae within the WSPs may now be nitrogen limited, a condition which may favour the growth of nitrogen-fixing cyanobacteria. The decrease in algal biomass and in dissolved oxygen levels may enhance sedimentary denitrification, further driving the system towards nitrogen limitation.

Optical Properties, Suspended Sediments, and Chemistry Associated with the Turbidity Maxima of the Delaware Estuary

1983 ◽  
Vol 40 (S1) ◽  
pp. s172-s179 ◽  
Author(s):  
Robert B. Biggs ◽  
Jonathan H. Sharp ◽  
Thomas M. Church ◽  
John M. Tramontano
Keyword(s):  
Optical Properties ◽  
Trace Metals ◽  
Attenuation Coefficient ◽  
Inorganic Nitrogen ◽  
Suspended Sediments ◽  
Inorganic Phosphorus ◽  
Turbidity Maximum ◽  
Salinity Range ◽  
Delaware Estuary ◽  
High Concentrations

Two turbidity maxima were found in the Delaware Estuary and were distinct both in terms of optical properties of the water and in quantity of suspended material. The upstream maximum occurred at about 1‰ salinity. Both the diffuse attenuation coefficient (KD) and the beam attenuation coefficient (α) responded to the double turbidity maxima. The upstream maximum contains a larger number of individual mineral grains with a mean diameter of about 3 μm; the downstream maximum, which occurred at salinities of 7.5–10‰, was dominated by composite particles with a mean size of 12 μm; at salinities > 10‰, the suspended sediment population was dominated by large (10–20 μm) individual particles with few composite particles.Nutrients, productivity, particulate organic matter, and dissolved and particulate metals all showed relationships to the turbidity maxima when viewed on salinity and on geographic axes. An excess of dissolved inorganic nitrogen in relation to dissolved inorganic phosphorus was mirrored by exceptionally low particulate C/P ratios in the region of the turbidity maxima. Primary productivity appeared to be greatly reduced in the region of the downstream turbidity maximum.The trace metals Fe, Mn, Cd, Cu, Co, and Ni showed a general association with particulate phases at lowest salinities, at the upstream turbidity maximum. The more particle reactive metals (Fe, Mn, and Co) reflected this as enrichment relative to particulate aluminum. At the downstream turbidity maximum, in the mid-salinity range, the trace metals showed a minimum relative to Al, probably due to dilution by resuspended bottom sediments. In the lower estuary, the trace metals exhibited the highest enrichment (relative to aluminum) and an association with high concentrations of particulate carbon.Key words: Delaware Estuary, turbidity maxima, optical properties, suspended sediments, chemistry

scholarly journals Deterioration in the water quality of an urbanised estuary with recommendations for improvement

Water SA ◽  
2019 ◽  
Vol 45 (1 January) ◽  
Author(s):  
Adams JB ◽  
L Pretorius ◽  
GC Snow
Keyword(s):  
Water Quality ◽  
Inorganic Nitrogen ◽  
Vertical Mixing ◽  
Primary Source ◽  
Inorganic Phosphorus ◽  
Quality Data ◽  
Spatial And Temporal Variability ◽  
Phytoplankton Blooms ◽  
Water Quality Data

Water quality characteristics of the heavily urbanised and industrialised Swartkops River and Estuary in the Eastern Cape have been the focus of several studies since the 1970s. Overloaded and poorly maintained wastewater treatment works (WWTWs), polluted stormwater runoff and solid waste have all contributed to the deterioration in the water quality of the river and estuary. The objective of this study was to determine the current water quality status of the Swartkops Estuary, by investigating spatial and temporal variability in physico-chemical parameters and phytoplankton biomass and where possiblerelate this to historical water quality data. The present study found evidence suggesting that water is not flushed as efficiently from the upper reaches of the estuary as was previously recorded. Reduced vertical mixing results in strong stratification and persistent eutrophic conditions with phytoplankton blooms (> 20 μg chl a·L−1), extending from the middle reaches to the tidal head of the estuary. The Motherwell Canal was and still is a major source of nitrogen (particularly ammonium) to the estuary, but the Swartkops River is the primary source of phosphorus with excessive inputs from the cumulative effectof three WWTWs upstream. An analysis of historical water quality data in the Swartkops Estuary (1995 to 2013) shows that all recorded dissolved inorganic phosphorus measurements were classified as hypertrophic (> 0.1 mg P·L−1), whereas 41% of dissolved inorganic nitrogen measurements were either mesotrophic or eutrophic. If nutrient removal methods at the three WWTWs were improved and urban runoff into the Motherwell Canal better managed, it is likely that persistent phytoplankton blooms and health risks associated with eutrophication could be reduced.

Cholecalciferol has no effect on calcium and inorganic phosphorus balance in a naturally cholecalciferol-deplete subterranean mammal, the naked mole rat (Heterocephalus glaber)

1991 ◽  
Vol 129 (1) ◽  
pp. 21-26 ◽  
Author(s):  
R. Buffenstein ◽  
S. Yahav
Keyword(s):  
Biological Significance ◽  
Inorganic Phosphorus ◽  
Heterocephalus Glaber ◽  
Mole Rat ◽  
Glomerular Filtrate ◽  
Independent Process ◽  
Subterranean Mammal ◽  
Almost All ◽  
Underground Habitat ◽  
Circulating Levels

ABSTRACT Naked mole rats, Heterocephalus glaber, have no obvious source of cholecalciferol (D3) available to them, given their underground habitat and tubiferous diet. They have undetectable levels of 25-OH-D3 and as such appear to be naturally deplete in D3. The effect of an oral D3 supplement on mineral balance and homeostasis was therefore investigated. This D3 treatment did not affect circulating levels of Ca2+ and inorganic phosphorus (Pi). Nor did D3 treatment affect mineral intake and absorption. The Ca2+ and Pi present in the food was efficiently extracted and absorbed, resulting in an apparent fractional absorption (AFA) efficiency exceeding 98%. Irrespective of D3 treatment, the amount of Ca2+ and Pi absorbed was positively correlated with the amount ingested, suggesting that intestinal uptake is by a passive D3-independent process. After D3 supplementation urinary Ca2+ secretion was unchanged; however, the amount of Pi excreted in the urine increased (P ≤ 0·05). This resulted in a concomitant decline in Pi AFR (P ≤ 0·02 from 99·95±0·02% to 99·82±0·03%). Almost all the Ca2+ and Pi in the glomerular filtrate were reabsorbed, facilitating AFR efficiencies that approach physiological maxima (> 99%). Changes in AFR efficiency with D3 supplementation are therefore of no biological significance. Net mineral flux of both elements, irrespective of D3 treatment, was positive. It is speculated that the ever-growing incisors of these animals act as mineral dumps and assist in the tight regulation of plasma Ca2+ and Pi. These data suggest that naked mole rats utilize mechanisms independent of D3 in regulating mineral homeostasis and are therefore well-adapted to an environment devoid of sunlight. Journal of Endocrinology (1991) 129, 21–26

The Annual Variations of Major Nutrients and Assessments about Environmental Impacts of Xiangshan Bay East China Sea

2013 ◽  
Vol 316-317 ◽  
pp. 395-399
Author(s):  
Gen Hai Zhu ◽  
Jian Qian ◽  
Li Hong Chen ◽  
Mao Jin ◽  
Jing Jing Liu ◽  
...  
Keyword(s):  
East China Sea ◽  
Sea Water ◽  
Inorganic Nitrogen ◽  
Inorganic Phosphorus ◽  
East China ◽  
Nitrogen And Phosphorus ◽  
China Sea ◽  
Annual Variations ◽  
Xiangshan Bay ◽  
Major Nutrients

The 30 years’ annual variations of major nutrients dissolved inorganic nitrogen(DIN) and dissolved inorganic phosphorus(DIP) in Xiangshan Bay East China Sea between 1982 and 2011 were reported. The results showed that the concentrations of nitrogen and phosphorus nutrients increased year by year, consistent with the trend of nitrogen and phosphorus consumption in our country. Inorganic nitrogen was the main pollutant, then was inorganic phosphorus in Xiangshan harbor. The annual average change of DIN ranged from 0.21 to 0.76 mg∙dm-3 while DIP ranged from 0.018 to 0.054 mg∙dm-3. And the change trend of DIN and DIP was as following: winter > autumn > summer > spring. The DIN and DIP in Xiangshan horbor exceeded the standard limits greatly, the water quality in culture areas exceeded national criteria for sea water Level IV and most water qualities were inferior Level IV.

Characterising and predicting algal blooms in a subtropical coastal lagoon

2014 ◽  
Vol 65 (3) ◽  
pp. 191 ◽  
Author(s):  
Kwee Siong Tew ◽  
Pei-Jie Meng ◽  
David C. Glover ◽  
Jih-Terng Wang ◽  
Ming-Yih Leu ◽  
...  
Keyword(s):  
Coastal Lagoon ◽  
Algal Blooms ◽  
Algal Bloom ◽  
Coastal Lagoons ◽  
Inorganic Nitrogen ◽  
Inorganic Phosphorus ◽  
Reliable Measure ◽  
Exponential Relationship ◽  
Outlet Channel ◽  
Chl A

Algal bloom is a major concern worldwide. In this study, we characterised the physical and biochemical parameters during an algal bloom event in a coastal lagoon in an attempt to predict local blooms in the future. Results showed that the highest concentrations of dissolved inorganic phosphorus (DIP), chlorophyll a (chl a) and phytoplankton abundance were found in the inner area, whereas the highest dissolved inorganic nitrogen (DIN) concentration occurred near the inlet-outlet channel. Chl a was correlated with DIP, and there was a significant exponential relationship between chl a and the nitrogen to phosphorus ratio (N/P ratio) across all sampling stations and times. A higher proportion of the variation in chl a was explained by the N/P ratio than either DIP or DIN. We found that a N/P ratio <2.38 will likely trigger an algal bloom (chl a ≥ 10 µgL–1) in the lagoon. Our results suggest that the N/P ratio could be used as an expedient and reliable measure of the potential eutrophic status of coastal lagoons.

scholarly journals Production, partitioning and stoichiometry of organic matter under variable nutrient supply during mesocosm experiments in the tropical Pacific and Atlantic Ocean

2012 ◽  
Vol 9 (11) ◽  
pp. 4629-4643 ◽  
Author(s):  
J. M. S. Franz ◽  
H. Hauss ◽  
U. Sommer ◽  
T. Dittmar ◽  
U. Riebesell
Keyword(s):  
Organic Matter ◽  
Coastal Upwelling ◽  
Global Climate ◽  
Inorganic Nitrogen ◽  
Euphotic Zone ◽  
N:P Ratio ◽  
Nutrient Supply ◽  
N Availability ◽  
Intermediate Water ◽  
The Impact

Abstract. Oxygen-deficient waters in the ocean, generally referred to as oxygen minimum zones (OMZ), are expected to expand as a consequence of global climate change. Poor oxygenation is promoting microbial loss of inorganic nitrogen (N) and increasing release of sediment-bound phosphate (P) into the water column. These intermediate water masses, nutrient-loaded but with an N deficit relative to the canonical N:P Redfield ratio of 16:1, are transported via coastal upwelling into the euphotic zone. To test the impact of nutrient supply and nutrient stoichiometry on production, partitioning and elemental composition of dissolved (DOC, DON, DOP) and particulate (POC, PON, POP) organic matter, three nutrient enrichment experiments were conducted with natural microbial communities in shipboard mesocosms, during research cruises in the tropical waters of the southeast Pacific and the northeast Atlantic. Maximum accumulation of POC and PON was observed under high N supply conditions, indicating that primary production was controlled by N availability. The stoichiometry of microbial biomass was unaffected by nutrient N:P supply during exponential growth under nutrient saturation, while it was highly variable under conditions of nutrient limitation and closely correlated to the N:P supply ratio, although PON:POP of accumulated biomass generally exceeded the supply ratio. Microbial N:P composition was constrained by a general lower limit of 5:1. Channelling of assimilated P into DOP appears to be the mechanism responsible for the consistent offset of cellular stoichiometry relative to inorganic nutrient supply and nutrient drawdown, as DOP build-up was observed to intensify under decreasing N:P supply. Low nutrient N:P conditions in coastal upwelling areas overlying O2-deficient waters seem to represent a net source for DOP, which may stimulate growth of diazotrophic phytoplankton. These results demonstrate that microbial nutrient assimilation and partitioning of organic matter between the particulate and the dissolved phase are controlled by the N:P ratio of upwelled nutrients, implying substantial consequences for nutrient cycling and organic matter pools in the course of decreasing nutrient N:P stoichiometry.

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