scholarly journals Dynamics of cyanobacteria and cyanobacterial toxins and their correlation with environmental parameters in Tri An Reservoir, Vietnam

2016 ◽  
Vol 14 (4) ◽  
pp. 699-712 ◽  
Author(s):  
Thanh-Son Dao ◽  
Jorge Nimptsch ◽  
Claudia Wiegand
Keyword(s):  
Inorganic Nitrogen ◽  
Oxygen Demand ◽  
Environmental Parameters ◽  
Nutrient Competition ◽  
Physical Conditions ◽  
Nitrogen Concentrations ◽  
Local Residents ◽  
Total Inorganic Nitrogen ◽  
Correlation With Environmental Parameters ◽  
Cyanobacterial Biomass

This study evaluates the water quality from Tri An Reservoir, a drinking water supply for several million people in southern Vietnam, in terms of cyanobacterial biomass and their potent toxins, microcystins (MCs). Cyanobacteria, their toxins and environmental parameters were monitored monthly for 1 year (April 2008–March 2009) at six stations covering a transect through the reservoir. Dynamics of cyanobacterial abundance in relation to cyanobacterial biomass, toxins and environmental factors were investigated. Environmental variables from Tri An Reservoir favored algal and cyanobacterial development. However, cyanobacterial biomass and proportion varied widely, influenced by physical conditions, available nutrients and nutrient competition among the phytoplankton groups. Cyanobacterial biomass correlated slightly positively to temperature, pH and biochemical oxygen demand (BOD5), but negatively to total inorganic nitrogen concentrations. During most of the sampling times, MC concentrations in the reservoir were quite low (≤0.07 μg L−1 MC-LR equivalent), and presented a slight positive correlation to BOD5, total nitrogen:total phosphorus ratio and cyanobacterial biomass. However, in cyanobacterial scum samples, which now and then occurred in the reservoir, MC concentrations reached up to 640 μg g−1 DW−1. The occurrence of MC in the reservoir poses a risk to local residents who use the water daily for domestic purposes.

scholarly journals Membrane integrated process for advanced treatment of high strength Opium Alkaloid wastewaters

2018 ◽  
Vol 77 (7) ◽  
pp. 1899-1908 ◽  
Author(s):  
Güçlü Insel ◽  
Ahmet Karagunduz ◽  
Murat Aksel ◽  
Emine Cokgor ◽  
Gokce Kor-Bicakci ◽  
...  
Keyword(s):  
Inorganic Nitrogen ◽  
Oxygen Demand ◽  
High Strength ◽  
Complete Removal ◽  
Advanced Treatment ◽  
Treated Effluent ◽  
Aeration System ◽  
Total Inorganic Nitrogen ◽  
Conductivity Parameter ◽  
Activated Sludge Systems

Abstract In this study, an integrated aerobic membrane bioreactor (MBR)-nanofiltration (NF) system has been applied for advanced treatment of Opium processing wastewaters to comply with strict discharge limits. Aerobic MBR treatment was successfully applied to high strength industrial wastewater. In aerobic MBR treatment, a non-fouling unique slot aeration system was designed using computational fluid dynamics techniques. The MBR was used to separate treated effluent from dispersed and non-settleable biomass. Respirometric modeling using MBR sludge indicated that the biomass exhibited similar kinetic parameters to that of municipal activated sludge systems. Aerobic MBR/NF treatment reduced chemical oxygen demand (COD) from 32,000 down to 2,500 and 130 mg/L, respectively. The MBR system provided complete removal of total inorganic nitrogen; however, nearly 50 mgN/L organic nitrogen remained in the permeate. Post NF treatment after MBR permeate reduced nitrogen below 20 mgN/L, providing nearly total color removal. In addition, a 90% removal in the conductivity parameter was reached with an integrated MBR/NF system. Finally, post NF application to MBR permeate was found not to be practical at higher pH due to low flux (3–4 L/m2/hour) with low recovery rates (30–40%). As the permeate pH lowered to 5.5, 75% of NF recovery was achieved at a flux of 15 L/m2/hour.

scholarly journals Comparison of hybrid membrane aerated biofilm reactor (MABR)/suspended growth and conventional biological nutrient removal processes

2021 ◽  
Vol 83 (6) ◽  
pp. 1418-1428
Author(s):  
Avery L. Carlson ◽  
Huanqi He ◽  
Cheng Yang ◽  
Glen T. Daigger
Keyword(s):  
Inorganic Nitrogen ◽  
Oxygen Demand ◽  
Primary Treatment ◽  
Biofilm Reactor ◽  
Biological Nutrient Removal ◽  
Biofilm Reactors ◽  
Suspended Growth ◽  
Total Inorganic Nitrogen ◽  
Tin Removal ◽  
Biological Phosphorus

Abstract Mathematical modelling was used to investigate the possibility to use membrane aerated biofilm reactors (MABRs) in a largely anoxic suspended growth bioreactor to produce the nitrate-nitrogen required for heterotrophic denitrification and the growth of denitrifying phosphorus accumulating organisms (DPAOs). The results indicate that such a process can be used to achieve a variety of process objectives. The capture of influent biodegradable organic matter while also achieving significant total inorganic nitrogen (TIN) removal can be achieved with or without use of primary treatment by operation at a relatively short suspended growth solids residence time (SRT). Low effluent TIN concentrations can also be achieved, irrespective of the influent wastewater chemical oxygen demand (COD)/total nitrogen (TN) ratio, with somewhat larger suspended growth SRT. Biological phosphorus and nitrogen removal can also be effectively achieved. Further experimental work is needed to confirm these modelling results.

scholarly journals Sulphur and nitrogen concentrations and fluxes in bulk precipitation and throughfall in the mountain and highland spruce stands in the Czech Republic

2010 ◽  
Vol 56 (No. 10) ◽  
pp. 429-441 ◽  
Author(s):  
I. Drápelová ◽  
L. Menšík ◽  
J. Kulhavý ◽  
I. Marková
Keyword(s):  
Czech Republic ◽  
Inorganic Nitrogen ◽  
Ammonium Nitrogen ◽  
Nitrogen Compounds ◽  
Bulk Precipitation ◽  
Sulphur Deposition ◽  
The Czech Republic ◽  
Spruce Stands ◽  
Nitrogen Concentrations ◽  
Total Inorganic Nitrogen

Concentrations and fluxes of sulphur and nitrogen compounds in bulk precipitation and in throughfall were evaluated and compared for two experimental sites in the Czech Republic: one situated at R&aacute;jec (Drahansk&aacute; upland, 610 m a.s.l.) and the second one at B&iacute;l&yacute; Kř&iacute;ž (Moravian-Silesian Beskids, 908 m a.s.l.) both with similar stands of young Norway spruce. The three-year study performed during 2006&ndash;2008, revealed statistically significant differences in nitrate nitrogen concentrations in bulk precipitations and in ammonium nitrogen concentrations both in bulk precipitation and in throughfall between the two sites. Higher nitrogen compounds concentrations in bulk precipitation were found at R&aacute;jec. Differences between the two sites in sulphur concentrations were not found out neither in bulk precipitation nor in throughfall waters. Total sulphur deposition amounted to 8.1, 8.3 and 6.7 kg S&middot;ha<sup>&ndash;1</sup> at R&aacute;jec and to 14.8, 16.9 and 15.4 kg S&middot;ha<sup>&ndash;1</sup> at Beskids for the three years studied, respectively. Total inorganic nitrogen throughfall flux amounted to 12.1, 11.6 and 11.6 at R&aacute;jec and 13.8, 18.9 and 15.0 kg&middot;ha<sup>&ndash;1</sup> at B&iacute;l&yacute; Kř&iacute;ž for the years 2006, 2007 and 2008, respectively. &nbsp;

scholarly journals Direct resource recovery from sewage using a combined system of anaerobic-aerobic biological treatment and food production

2021 ◽  
Author(s):  
Daisuke Tanikawa ◽  
Kenta Shimomura ◽  
Daisuke Motokawa ◽  
Yuya Itoiri ◽  
Zen-Ichiro Kimura
Keyword(s):  
Food Production ◽  
Inorganic Nitrogen ◽  
Low Cost ◽  
Sewage Treatment ◽  
Oxygen Demand ◽  
Resource Recovery ◽  
Ammonia Oxidizing Bacteria ◽  
Recycled Water ◽  
Combined System ◽  
Total Inorganic Nitrogen

Abstract A combined system of an anaerobic baffled reactor (ABR), a down-flow hanging sponge (DHS) reactor, an aquarium tank (AT), and a constructed wetland (CWL) was proposed as a new concept for sewage treatment. The ABR and DHS reactor, AT, and CWL were applied for biological sewage treatment, bioassay, and nutrient removal with food production, respectively. Killifishes and tomatoes were cultivated in the AT and CWL, respectively. In the ABR, 81.3% of total chemical oxygen demand and 76.5% of total biochemical oxygen demand were removed at 5.1 h of the hydraulic retention time (HRT). Most remaining organic matter and 47.1% of ammonia were removed in the DHS reactor. In the CWL, 97.0% of total inorganic nitrogen and 78.6% of phosphate were removed with a 3.87 kg/m2 of tomatoes producing yield at 4.4 days of the HRT. In addition, anaerobic ammonium-oxidizing bacteria Candidatus Scalindua and ammonia-oxidizing bacteria Nitrospira and Nitorosococcus were considered as contributors to nitrogen removal in the CWL. The final effluent's water can be utilized as recycled water by installation of sand filtration and disinfection processes. Therefore, the proposed system can be applied as a low-energy, low-cost sewage treatment system with direct resource recovery.

Comparison of the pollutant loads in dry and wet weather runoff in a southern California urban watershed

2002 ◽  
Vol 45 (9) ◽  
pp. 255-261 ◽  
Author(s):  
T.N. McPherson ◽  
S.J. Burian ◽  
H.J. Turin ◽  
M.K. Stenstrom ◽  
I.H. Suffet
Keyword(s):  
Southern California ◽  
Inorganic Nitrogen ◽  
Oxygen Demand ◽  
Management Plan ◽  
Deterministic Models ◽  
Relative Contribution ◽  
Creek Watershed ◽  
Total Inorganic Nitrogen ◽  
Wet Weather ◽  
Kjeldahl Nitrogen

This research compares the relative contributions of potential contaminants discharged in dry weather flow (DWF) and wet weather flow (WWF) from the highly urbanized Ballona Creek watershed (BCW) in southern California using empirical and deterministic models. These models were used to compare the loading of the following pollutants: total suspended solids, biochemical oxygen demand, total nitrogen, total inorganic nitrogen, total Kjeldahl nitrogen, total phosphorus, copper, lead, arsenic, nickel, cadmium, and chromium. The results indicate DWF contributes approximately 10–30% of the total annual flow discharged from Ballona Creek. The annual DWF volume was fairly consistent; the variation in DWF percentage contribution was dependent on the highly variable volume of WWF. The relative contribution to the annual pollutant load varied considerably between each pollutant. In general, the DWF load was found to be significant, especially in years with lower precipitation totals. The results from this investigation have identified the relative relationship between DWF and WWF loads in the BCW and will aid in the decision-making process during the development of an integrated DWF-WWF management plan and allocation of water pollution control funds between DWF and WWF management.

Implementation of Self-Organizing Maps (SOM) to analyses of environmental parameters and phytoplankton biomass in a macrotidal estuary and artificial lake

2012 ◽  
Vol 93 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Roksana Jahan ◽  
Hyu Chang Choi ◽  
Young Seuk Park ◽  
Young Cheol Park ◽  
Ji Ho Seo ◽  
...  
Keyword(s):  
Phytoplankton Biomass ◽  
Algal Blooms ◽  
Suspended Solids ◽  
Inorganic Nitrogen ◽  
Environmental Parameters ◽  
Ecological Data ◽  
Self Organizing Maps ◽  
Macrotidal Estuary ◽  
Phytoplankton Communities ◽  
Self Organizing

Self-Organizing Maps (SOM) have been used for patterning and visualizing ten environmental parameters and phytoplankton biomass in a mactrotidal (>10 m) Gyeonggi Bay and artificial Shihwa Lake during 1986–2004. SOM segregated study areas into four groups and ten subgroups. Two strikingly alternative states are frequently observed: the first is a diverse non-eutrophic state designated by three groups (SOM 1–3), and the second is a eutrophic state (SOM 4: Shihwa Lake and Upper Gyeonggi Bay; summer season) characterized by enhanced nutrients (3 mg l−1 dissolved inorganic nitrogen, 0.1 mg l−1 PO4) that act as a signal and response to that signal as algal blooms (24 µg chlorophyll-a l−1). Bloom potential in response to nitrification is affiliated with high temperature (r = 0.26), low salinity (r = −0.40) and suspended solids (r = –0.27). Moreover, strong stratification in the Shihwa Lake has accelerated harmful algal blooms and hypoxia. The non-eutrophic states (SOM 1–3) are characterized by macro-tidal estuaries exhibiting a tolerance to pollution with nitrogen-containing nutrients and retarding any tendency toward stratification. SOM 1 (winter) is more distinct from SOM 4 due to higher suspended solids (>50 mg l−1) caused by resuspension that induces light limitation and low chlorophyll-a (<5 µg l−1). In addition, eutrophication-induced shifts in phytoplankton communities are noticed during all the seasons in Gyeonggi Bay. Overall, SOM showed high performance for visualization and abstraction of ecological data and could serve as an efficient ecological map that can specify blooming regions and provide a comprehensive view on the eutrophication process in a macrotidal estuary.

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