scholarly journals Spatiotemporal Dissolved Silicate Variation, Sources, and Behavior in the Eutrophic Zhanjiang Bay, China

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3586
Author(s):  
Peng Zhang ◽  
Jia-Lei Xu ◽  
Ji-Biao Zhang ◽  
Jian-Xu Li ◽  
Yan-Chan Zhang ◽  
...  
Keyword(s):  
Coastal Water ◽  
Anthropogenic Activities ◽  
Inorganic Nitrogen ◽  
Water Discharge ◽  
Inorganic Phosphorus ◽  
Average Concentration ◽  
Source Water ◽  
Input Concentration ◽  
Planktonic Diatoms ◽  
Dissolved Silicate

Dissolved silicate (DSi) is an important nutrient in coastal water, which is used by planktonic diatoms for cell division and growth. In this study, surface water samples were collected in the eutrophic Zhanjiang Bay (ZJB) in 2019, covering a seasonal variation of coastal water and land-based source water discharge. The spatiotemporal DSi distribution, land-based sources flux input and behaviors in ZJB were studied and discussed. The results show that the DSi concentration had significant differences in spatiotemporal scale. The average concentration of DSi in ZJB was 38.00 ± 9.48 μmol·L−1 in spring, 20.23 ± 11.27 μmol·L−1 in summer, 12.48 ± 1.42 μmol·L−1 in autumn and 11.96 ± 4.85 μmol·L−1 in winter. The spatiotemporal DSi distribution showed a decreasing gradient from the top to the mouth of ZJB, which was affected by land source inputs and hydrodynamics. The land-based sources’ input concentration of DSi in ZJB ranged from 0.021 to 0.46 mol·L−1, with an average of 0.14 mol·L−1, and the total annual flux of DSi was 1.06 × 109 mol, comprising up to 8.28%, 41.55% and 50.17% in dry, normal, and wet seasons, respectively. The Suixi River contributed the highest DSi flux proportion in all seasons. The DSi in land-based source water was mainly affected by water flow discharge, diatom uptake and impacts from anthropogenic activities. Compared with dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphorus (DIP), the DSi was the limitation nutrient in ZJB. Additionally, the DSi concentration in the coastal water was negatively correlated with salinity. The seasonal DSi/DIN and DSi/DIP ratios in land-based sources discharge water was significantly higher than that in coastal water (p < 0.05). Land-based sources of DSi input played an important role in nutrients composition that sustained diatoms as the dominant species in ZJB.

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 Suspended Particular Matter drives the spatial segregation of nitrogen turnover along the hyper-turbid Ems estuary

2021 ◽  
Author(s):  
Gesa Schulz ◽  
Tina Sanders ◽  
Justus E. E. van Beusekom ◽  
Yoana G. Voynova ◽  
Andreas Schöl ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Nitrous Oxide ◽  
Water Column ◽  
Anthropogenic Activities ◽  
Inorganic Nitrogen ◽  
Nitrate Removal ◽  
Tidal River ◽  
Nutrient Loads ◽  
Ems Estuary ◽  
Nitrogen Turnover

Abstract. Estuaries are nutrient filters and change riverine nutrient loads before they reach coastal oceans. They have been extensively changed by anthropogenic activities like draining, deepening, and dredging to meet economic and social demand, causing significant regime changes like tidal amplifications and in some cases to hyper-turbid conditions. Furthermore, increased nutrient loads, especially nitrogen, mainly by agriculture cause coastal eutrophication. Estuaries can either act as a sink or as a source of nitrate, depending on environmental and geomorphological conditions. These factors vary along an estuary, and change nitrogen turnover in the system. Here, we investigate the factors controlling nitrogen turnover in the hyper-turbid Ems estuary (Northern Germany) that has been strongly impacted by human activities. During two research cruises in August 2014 and June 2020, we measured water column properties, dissolved inorganic nitrogen, dual stable isotopes of nitrate and dissolved nitrous oxide concentration along the estuary. Overall, the Ems estuary acts as a nitrate sink in both years. However, three distinct biogeochemical zones exist along the estuary. A strong fractionation (~ 26 ‰) of nitrate stable isotopes points towards nitrate removal via water column denitrification in the hyper-turbid Tidal River, driven by anoxic conditions in deeper water layers. In the Middle Reaches of the estuary nitrification gains in importance turning this section into a net nitrate source. The Outer Reaches are dominated by mixing with nitrate uptake in 2020. We find that the overarching control on biogeochemical nitrogen cycling, zonation and nitrous oxide production in the Ems estuary is exerted by suspended particulate matter concentrations and the linked oxygen deficits.

scholarly journals Abatement vs. treatment for efficient diffuse source water pollution management in terrestrial-marine systems

2015 ◽  
Vol 72 (5) ◽  
pp. 730-737 ◽  
Author(s):  
P. C. Roebeling ◽  
M. C. Cunha ◽  
L. Arroja ◽  
M. E. van Grieken
Keyword(s):  
Water Pollution ◽  
Management Practices ◽  
Inorganic Nitrogen ◽  
Pollution Abatement ◽  
Source Water ◽  
Diffuse Source ◽  
Marine Systems ◽  
Pollution Management ◽  
Pollution Treatment ◽  
Water Pollution Management

Marine ecosystems are affected by water pollution originating from coastal catchments. The delivery of water pollutants can be reduced through water pollution abatement as well as water pollution treatment. Hence, sustainable economic development of coastal regions requires balancing of the marginal costs from water pollution abatement and/or treatment and the associated marginal benefits from marine resource appreciation. Water pollution delivery reduction costs are, however, not equal across abatement and treatment options. In this paper, an optimal control approach is developed and applied to explore welfare maximizing rates of water pollution abatement and/or treatment for efficient diffuse source water pollution management in terrestrial-marine systems. For the case of diffuse source dissolved inorganic nitrogen water pollution in the Tully-Murray region, Queensland, Australia, (agricultural) water pollution abatement cost, (wetland) water pollution treatment cost and marine benefit functions are determined to explore welfare maximizing rates of water pollution abatement and/or treatment. Considering partial (wetland) treatment costs and positive water quality improvement benefits, results show that welfare gains can be obtained, primarily, through diffuse source water pollution abatement (improved agricultural management practices) and, to a minor extent, through diffuse source water pollution treatment (wetland restoration).

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.

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.

Characterization of dissolved organic matter and disinfection characteristics of source water from the Pearl River

2007 ◽  
Vol 7 (2) ◽  
pp. 205-212
Author(s):  
Z.Y. Zhao ◽  
J.D. Gu ◽  
H.B. Li
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Chlorine Dioxide ◽  
Anthropogenic Activities ◽  
Apparent Molecular Weight ◽  
Water Disinfection ◽  
Size Exclusion ◽  
Pearl River ◽  
Source Water ◽  
Raw Water

Source water samples were collected from Guangzhou segment of Pearl River and filtered through Amicon® YC-05, YM-1, YM-3, YM-10, YM-30, YM-100 and ZM-500 membranes sequentially after pre-treatment. The apparent molecular weights of the 8 fractions were calibrated using high-performance size exclusion chromatograph (HPSEC) and they ranged from 0.36 to 182.6 kDa. These fractionated isolates and the raw water were disinfected by chlorine or chlorine dioxide to determine their disinfection characteristics. Results showed that apparent molecular weight of the main dissolved organic matter (DOM) in the RO isolate of water sample was less than 360 Da and this part of the DOM was mainly from anthropogenic activities and contamination of wastewater. RO fraction was the controlling factor for the raw water disinfection process according to the THMs concentrations detected. Disinfection by chlorine dioxide produced less THMs that by chlorine.

scholarly journals DISSOLVED SILICATE IN COASTAL WATER OF SOUTH SULAWESI

2015 ◽  
Vol 6 (2) ◽  
Author(s):  
Muhammad Lukman ◽  
Andriani Nasir ◽  
Khairul Amri ◽  
Rahmadi Tambaru ◽  
Muhammad Hatta ◽  
...  
Keyword(s):  
Water Quality ◽  
Chlorophyll A ◽  
Coastal Water ◽  
Coastal Waters ◽  
Dry Season ◽  
Limiting Factor ◽  
Western Coast ◽  
Wet Season ◽  
South Sulawesi ◽  
Dissolved Silicate

ABSTRACT Dissolved silicate (DSi) in coastal waters plays a crucial role in phytoplankton growth particularly diatom. This study aimed to determine DSi concentration seasonally in waters of the western coast of South Sulawesi in relation to coastal water quality indicator. Water, chlorophyll-a, and diatom samples were collected from the coastal areas of the Tallo-Makassar, Maros, and Pangkep, in April 2013 (transitional season), June 2013 (dry season), and February 2014 (wet season). Factorial analysis of variance was used to identify significant seasonal and temporal variations, and linear regression was used to test the relationship of chlorophyll-a and diatom abundance to DSi concentrations. The results showed that the DSi concentration was higher in the wet season of 35.2-85.2 µM than in the other seasons (transitional season: 10.8-68.4 µM, dry season: 9.59-24.1 µM). The abundance of diatoms during the transitional season reached ~9.7x107 cell/m3 in the Pangkep river, 2.3x107 cell/m3 in the Tallo river, and 1.3 x 107 cell/m3 in the Maros river. Chaetoceros, Nitzschia, and Rhizosolenia dominated the diatom composition. The mean concentration of chlorophyll-a in the Makassar coastal waters was 4.52±4.66 mg/m3, while in the Maros and Pangkep waters of 1.40±1.06, and 2.72±1.94  mg/m3, respectively. There was no strong linear corelation between DSi and diatom abundances, nor chlorophyll-a. These results suggested that DSi become a non-limiting factor for the diatom growth and potentially reduce the water quality via eutrophication and diatom blooms. Keywords: dissolved silicate, diatom, chlorophyll-a, coastal waters, South Sulawesi

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