scholarly journals INCA Modelling of the Lee System: strategies for the reduction of nitrogen loads

2002 ◽  
Vol 6 (3) ◽  
pp. 467-484 ◽  
Author(s):  
N. J. Flynn ◽  
T. Paddison ◽  
P. G. Whitehead

Abstract. The Integrated Nitrogen Catchment model (INCA) was applied successfully to simulate nitrogen concentrations in the River Lee, a northern tributary of the River Thames for 1995-1999. Leaching from urban and agricultural areas was found to control nitrogen dynamics in reaches unaffected by effluent discharges and abstractions; the occurrence of minimal flows resulted in an upward trend in nitrate concentration. Sewage treatment works (STW) discharging into the River Lee raised nitrate concentrations substantially, a problem which was compounded by abstractions in the Lower Lee. The average concentration of nitrate (NO3) for the simulation period 1995-96 was 7.87 mg N l-1. Ammonium (NH4) concentrations were simulated less successfully. However, concentrations of ammonium rarely rose to levels which would be of environmental concern. Scenarios were run through INCA to assess strategies for the reduction of nitrate concentrations in the catchment. The conversion of arable land to ungrazed vegetation or to woodland would reduce nitrate concentrations substantially, whilst inclusion of riparian buffer strips would be unsuccessful in reducing nitrate loading. A 50% reduction in nitrate loading from Luton STW would result in a fall of up to 5 mg N l-1 in the reach directly affected (concentrations fell from maxima of 13 to 8 mg N l-1 , nearly a 40 % reduction), whilst a 20% reduction in abstractions would reduce maximum peaks in concentration in the lower Lee by up to 4 mg l-1 (from 17 to 13 mg N l-1, nearly a 25 % reduction),. Keywords: modelling, water quality, nitrogen, nitrate, ammonium, INCA, River Lee, River Thames, land-use.

1956 ◽  
Vol 34 (1) ◽  
pp. 1-15 ◽  
Author(s):  
S. M. Pady ◽  
L. Kapica

Numbers and kinds of fungi were determined from nutrient plate and silicone slide studies from the roof of the Sun Life Building, Montreal, between September 1950 and December 1951. Exposures of plates were made in the General Electric Bacterial Air Sampler, and plates and silicone slides in the Bourdillon Slit Sampler. A total of 978 exposures was made on 113 sampling days during 16 months; 507 plates in the G. E. Sampler, 344 plates and 127 slides in the Slit Sampler. Of 40,359 colonies examined, Cladosporium, Penicillium, yeasts, Aspergillus, Alternaria, and Actinomycetes were commonest, constituting 47.7, 15.8, 10.4, 4.6, 4.2, and 2.2% of the total. The next commonest fungi were Pullularia, Oöspora, Fusarium, Stemphylium, Verticillium, Rhizopus, Spicaria, Scopulariopsis, Phoma, Mucor, Botrytis, Cephalosporium, Trichoderma, Helmin-thosporium, Neurospora, Papularia, Cephalothecium, Pyrenochaeta, Zythia, and Nigrospora. In addition 12 genera were infrequently found. Unidentified colonies numbered 174 and nonsporulating 3371 (8.3%). On a cubic foot basis numbers in the plates varied from 17.7 per cu. ft. in August to 0.4 per cu. ft in February.Fungus spores showed a seasonal variation with summer highs averaging 244 per cu. ft. in July to a low of 0.8 per cu. ft. in December. The most abundant spores were Cladosporium, yeasts, smuts, Fusarium, Alternaria, Venturia-like, Stemphylium, rusts, Septoria, and Helminthosporium. Hyphal fragments and pollen grains were present also. On eight occasions during the summer, readings of over 200 spores per cu. ft. were recorded, the maximum being 445 per cu. ft. on September 6, 1951. Cladosporium in August reached a peak of 74.1 per cu. ft. and yeast cells in July had an average concentration of 100 per cu. ft.An analysis of the air masses indicated that pure polar air carried low numbers of fungi, whereas tropical air had very high numbers. Most of the air masses were modified polar air and their fungus content varied considerably. The fungi in the air over Montreal are believed to have had their origin in agricultural areas.


Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 515
Author(s):  
Luca Regni ◽  
Maria Luce Bartucca ◽  
Euro Pannacci ◽  
Francesco Tei ◽  
Daniele Del Buono ◽  
...  

Water pollution by excessive amounts of nitrate (NO3−) has become a global issue. Technologies to clean up nitrate-contaminated water bodies include phytoremediation. In this context, this research aimed to evaluate four tree species (Salix alba L., Populus alba L., Corylus avellana L. and Sambucus nigra L.) to remediate nitrate-contaminated waters (100 and 300 mg L−1). Some physiological parameters showed that S. alba L. and P. alba L. increased particularly photosynthetic activity, chlorophyll content, dry weight, and transpired water, following the treatments with the above NO3− concentrations. Furthermore, these species were more efficient than the others studied in the phytodepuration of water contaminated by the two NO3− levels. In particular, within 15 days of treatment, S. alba L. and P. alba L. removed nitrate quantities ranging from 39 to 78%. Differently, C. avellana L. and S. nigra L. did not show particular responses regarding the physiological traits studied. Nonetheless, these species removed up to 30% of nitrate from water. In conclusion, these data provide exciting indications on the chance of using S. alba L. and P. alba L. to populate buffer strips to avoid NO3− environmental dispersion in agricultural areas.


2019 ◽  
Vol 69 (3) ◽  
pp. 288-297 ◽  
Author(s):  
Anatoli Vassiljev ◽  
Ivar Annus ◽  
Nils Kändler ◽  
Katrin Kaur

Abstract In addition to traditional sources, drained peat soils have been found to be a significant source of nitrogen in Estonia. As a result, supplementary measures are required to improve water quality in rivers. Modelling is a widespread method to select means for improving water quality. At present, modelling of nitrogen in rivers has been concentrated on the influence of agricultural activity. However, drained peat can increase nitrogen concentrations even without fertilization and farming activities. This investigation describes the attempt to model water quality in the watershed with a large share of drained peat soils. The results showed a good alignment between measured and modelled nitrate concentrations using the MACRO and the SOILN for MACRO models. Some measures to improve water quality were tested using these models.


2020 ◽  
Vol 20 (4) ◽  
pp. 1484-1492
Author(s):  
Denny Helard ◽  
Shinta Indah ◽  
Michella Oktavia

Abstract The objective of this study is to analyze the spatial variability of ammonia, nitrite, and nitrate concentrations along the Batang Arau River, one of the most important rivers in West Sumatera, Indonesia. The results showed that the ammonium, nitrite, and nitrate concentrations were in the range of 0.180–0.510 mg/L, 0.0–0.178 mg/L, and 0.675–1.165 mg/L, respectively. The ammonium and nitrate concentrations were still below the maximum permissible concentrations for the river water quality standard of class II established by the Regulation Governor of West Sumatera at all of the sampling locations, except at midstream for ammonium, while the nitrite concentration had exceeded the quality standard from midstream to downstream of the river. The increase of the nitrogen concentration was observed from upstream to downstream of the river. Spatial analysis shows significant differences in nitrogen concentrations were obtained between the upstream and the midstream of the Batang Arau River (p < 0.05) but were not observed between the midstream and the downstream. This indicates the effect of different anthropogenic activities along the river. Based on the obtained results, for an effective monitoring program of the nitrogen concentration along the Batang Arau River, reducing the sampling locations from eight to five could be implemented.


Proceedings ◽  
2018 ◽  
Vol 2 (11) ◽  
pp. 619 ◽  
Author(s):  
Anatoli Vassiljev ◽  
Ivar Annus ◽  
Nils Kändler ◽  
Katrin Kaur

Investigations have indicated that in addition to traditional sources, drained peat soils can be considered as a significant source of nitrogen in Estonia. This changes the measures to improve water quality in rivers. At present modelling of nitrogen in rivers has been concentrated on influence of agricultural activity. However, drained peat can increase nitrogen concentrations even without fertilization and farming activities. This investigation describes the attempt to model water quality in the watershed with large share of drained peat soils. A good alignment between measured and modelled nitrate concentrations using the MACRO and the SOILN for MACRO models was shown.


2001 ◽  
Vol 44 (10) ◽  
pp. 101-106 ◽  
Author(s):  
M. Tateda ◽  
N.V. Hung ◽  
H. Kaku ◽  
M. Asano ◽  
M. Ike ◽  
...  

A method of quantitative analysis of nonylphenol polyethoxylates (NPnEOs) and their biodegration products (NPE-BDPs) in sewage sludge, which is effective, economical, and applicable to a high performance liquid chromatography was developed and actual sludge samples collected from Japanese sewage treatment plants (STPs) were analyzed using the method to confirm its effectiveness. Soxhlet extraction showed better recovery in a spike and recovery test than shaking extraction. Among the four pretreatments for Soxhlet extraction tested, the condition in which samples were freeze-dried, ultrasonicated, and extracted with methanol showed the best recovery efficiency. Quantitative analysis of NPE-BDPs in STP sludge resulted in 6.1 μg/g, 4.3 μg/g, and 8. μg/g in average concentration for NPnEOs (n=1-3), NPnEOs (n=4-18), and nonylphenol ethoxycarboxylates (NPnECs (n=1-3)), respectively, and the values of concentration were 100-1000 times higher than those in effluent at Japan's STPs. The results implied importance of quantitation of NPE-BDPs in sewage sludge to assess the risk to the environment.


Author(s):  
Karolina Sawa ◽  
Leszek Hejduk ◽  
Johannes Deelstra ◽  
Lillian Øygarden

Nutrient output from rural areas on the example of two catchments Skuterud and Zagożdżonka In this paper, two rural catchment - the Zagożdżonka catchment in Poland and the Skuterud catchment in Aas, Akershus county in Norway are compared. In addition to the general description, more in particular information, runoff, N-NO3 load, P-PO4 load, total phosphorus and total nitrogen concentrations in streams are compared. The data compared are from 1993 to 1995 in Zagożdżonka catchment and from 1994-1996 from Skuterud catchment. The average concentration of N-NO3 in Zagożdżonka River in the period was 0.85 mg·l-1 and the mean concentration of P-PO4 was 0.13 mg·l-1. In the stream in Skuterud catchment the average concentration of N-NO3 was 4.95 mg·l-1 and the mean concentration of P-PO4 was 0.04 mg·l-1. For both catchments the same data were also compared for the 2008. In Skuterud catchment the highest concentration of nutrients occurred in November, March and April, which was connected to the higher runoff from agricultural areas during the snowmelt period. In Zagożdżonka catchment the highest concentration of nutrients was noted in March, April and in summer time, which was connected to periods with high amounts of precipitation. Comparison of the two rural catchments showed many differences in applied measurement methods for water sampling, water measurement, discharge measurement, runoff amounts and management practices, which had an effect on results of monitoring program. The compared data can be useful to predict the development of future environmental conditions for example water quality. It can also be useful for predict how nutrient runoff will be in future. What is more the different conditions for runoff in Skuterud and Zagożdżonka then different measures are needed.


2012 ◽  
Vol 610-613 ◽  
pp. 1099-1102 ◽  
Author(s):  
Zhen Wang ◽  
Qi Zhang ◽  
Xiu Li Xu ◽  
Hai Ying Gao

Suspended sediment (SS) is one of the important parameters quantifying the degree of water pollution. In order to explore the spatiotemporal variation of the SS in Le’an river catchment, an important sub-catchment of Poyang lake basin, a total of 17 sampling points at rivers were selected for observations. Results show that, the concentration of SS is quite different across the catchment. The average concentration of SS in the upstream of the catchment with forest as the dominant land use, is 6.92mg/L, while the concentration in the downstream with a certain percentage of arable land is 14.39mg/L. The SS concentration shows an increasing trend from the upstream to the downstream, in correlation with the change of land uses. Also there exists a considerable deviation of the SS concentration in different seasons. The concentration in summer is relatively high, while lower in other seasons, with a likely relationship to rainfall events.


2010 ◽  
Vol 62 (11) ◽  
pp. 2501-2509 ◽  
Author(s):  
L. Y. Wang ◽  
X. H. Zhang ◽  
N. F. Y. Tam

Seven typical endocrine-disrupting chemicals (EDCs), including bisphenol A (BPA), 4-tert-octylphenol (OP), estrone (E1), estradiol (E2), 17α-estradiol (17α-E2), estriol (E3) and 17α-ethinylestradiol (EE2) in wastewater, were simultaneously determined with gas chromatography–mass spectrometry (GC–MS). Samples, including influents, effluents and wastewater of different unit processes, were taken seasonally from three different sewage treatment plants. The result showed that BPA and EE2 were the two main types of EDCs in all the samples. The average concentration of BPA were in the range of 268.1–2,588.5 ng l−1 in influents and 34.0–3,099.6 ng l−1 in effluents, while EE2 ranging from 133.1 to 403.2 ng l−1 and from 35.3 to 269.1 ng l−1, respectively. Seasonal change of EDCs levels in effluents was obvious between wet season and dry season. Besides, BPA and E3 could be effectively removed by the biological treatment processes (oxidation ditch and A2/O) with the unit removal of 64–91% and 63–100% for each compound, while other five EDCs had moderate or low removal rates. The study also proved that physical treatment processes, including screening, primary sedimentation and pure aeration, had no or little effect on EDCs removal.


2017 ◽  
Vol 43 (4) ◽  
pp. 58-65 ◽  
Author(s):  
Marta Małecka-Adamowicz ◽  
Łukasz Kubera ◽  
Wojciech Donderski ◽  
Katarzyna Kolet

AbstractThe study was aimed at evaluating microbial contamination on the premises of the sewage treatment plant by determining the concentrations of selected groups of airborne microorganisms. Another objective was to determine the antibiotic sensitivity patterns of isolated strains of staphylococci. The research was conducted in a seasonal cycle, by the impaction method using Merck MAS-100 air sampler. Samples were collected at six sites, each representing a different stage of sewage treatment. The susceptibility of isolated staphylococci was assessed with the disc-diffusion method, following the recommendations of the EUCAST. The results indicate that the microbial population in the air of the investigated area was dominated by mold fungi, whose highest average concentration was recorded at site IV located near the final clarifier (7672 CFU•m-3). Heterotrophic bacteria and mannitol-positive staphylococci were the most numerous at locations where sewage undergoes primary treatment. In each subseuqent stage the number of microorganisms emitted into the air from the sewage was lower. Antibiograms show that more than 50% of Staphylococcus spp. exhibited resistance to penicillin and 20% to rifampicin. In addition, 90% of the analyzed strains were sensitive to other antibiotics. The fungal community included the following genera: Cladosporium, Fusarium, Alternaria, Penicillium, Aspergillus, Aureobasidium, and Acremonium.The highest air contamination with all studied groups of microorganisms was recorded at the locations where mechanical sewage treatment was performed. During the subsequent stages lower numbers of heterotrophic bacteria were emitted into the air. The air in the investigated sewage treatment plant did not contain multidrug-resistant staphylococci.


Sign in / Sign up

Export Citation Format

Share Document