N2O emissions from secondary clarifiers and their contribution to the total emissions of the WWTP

2014 ◽  
Vol 70 (4) ◽  
pp. 720-728 ◽  
Author(s):  
Anna Mikola ◽  
Mari Heinonen ◽  
Heta Kosonen ◽  
Maarit Leppänen ◽  
Pirjo Rantanen ◽  
...  
Keyword(s):  
Wastewater Treatment Plants ◽  
Weather Conditions ◽  
Cold Weather ◽  
N2o Emissions ◽  
Warm Weather ◽  
Nitrification Process ◽  
Term Variation ◽  
Online Measurements ◽  
June July

Recent studies have indicated that the emissions of nitrous oxide, N2O, constitute a major part of the carbon footprint of wastewater treatment plants (WWTPs). Denitrification occurring in the secondary clarifier basins has been observed by many researchers, but until now N2O emissions from secondary clarifiers have not been widely reported. The objective of this study was to measure the N2O emissions from secondary clarifiers and weigh the portion they could represent of the overall emissions at WWTPs. Online measurements over several days were carried out at four different municipal WWTPs in Finland in cold weather conditions (March) and in warm weather conditions (June–July). An attempt was made to define the conditions in which N2O emissions from secondary clarifiers may occur. It was evidenced that large amounts of N2O can be emitted from the secondary clarifiers, and that the emissions have long-term variation. It was assumed that part of the N2O released in secondary clarification was originally formed in the activated sludge basin. The emissions from secondary clarification thus seem to be dependent on conditions of the nitrification and denitrification accomplished in the denitrification–nitrification process and on the amount of sludge stored in the secondary clarifiers.

The Relationship Between Self-Regulatory Efficacy and Physical Activity in Adolescents With a Caveat: A Cross-Lag Design Examining Weather

2020 ◽  
Vol 32 (4) ◽  
pp. 210-216
Author(s):  
Kathleen S. Wilson ◽  
Kevin S. Spink
Keyword(s):  
Physical Activity ◽  
Self Efficacy ◽  
Structural Equation ◽  
Weather Conditions ◽  
Cold Weather ◽  
Equation Modeling ◽  
Future Research ◽  
School Year ◽  
Warm Weather ◽  
The Relationship

Purpose: The use of self-efficacy to predict physical activity has a long history. However, this relationship is complex, as self-efficacy is thought to influence and be influenced by physical activity. The directionality of the self-regulatory efficacy (SRE) and physical activity relationship was examined using a cross-lagged design. A secondary purpose was to examine these relationships across differing weather conditions. Methods: Canadian adolescents (N = 337; aged between 13 and 18 years) completed the physical activity and SRE measures 4 times during a school year. Structural equation modeling was used to perform a cross-lag analysis. Results: The relationships between physical activity and SRE appeared to be weather dependent. During a more challenging weather period (eg, cold weather), the relationship between physical activity and SRE was bidirectional. However, no relationship emerged when the 2 constructs were assessed during a more optimal weather period (eg, warm weather). Conclusions: Some support has been provided for the bidirectional nature of the relationship between physical activity and SRE. The relationship appeared to be qualified by climate considerations, suggesting that future research examine how weather may relate not just to physical activity but also to the correlates of physical activity.

scholarly journals Long-term variation in an occurrence of Rhabditis orbitalis parasitic larvae (Nematoda, Rhabditidae) in the eyes of montane rodents

2006 ◽  
Vol 43 (4) ◽  
pp. 232-236
Author(s):  
M. Kocianová-Adamcová ◽  
M. Špakulová ◽  
E. Kocianová
Keyword(s):  
Weather Conditions ◽  
Clethrionomys Glareolus ◽  
Seasonal Abundance ◽  
Term Variation ◽  
Chionomys Nivalis ◽  
Tatra Mts ◽  
Vole Species ◽  
First Time ◽  
Long Term Survey

AbstractDuring a long-term survey (1999–2005) of parasitic larvae of nidicolous nematode Rhabditis orbitalis Sudhaus et Schulte, 1986 in the West Tatra Mts, the nematodes were detected in the eye orbits of snow voles Chionomys nivalis in 1999, 2004 and 2005. In the last year, R. orbitalis was detected also in another vole species Clethrionomys glareolus and Microtus tatricus both in previously studied site and in the Low Tatra Mts, however, it has never appeared at other rodent species. For the first time, an irregular occurrence of the R. orbitalis parasitic larvae has been ascertained in natural conditions of the Slovak mountains. The eye nematodes occurred only during autumn or cold and rather wet summer months, when density of the preferred host Ch. nivalis was relatively low. A hypothesis has been put forward that an occasional appearance of parasitic eye larvae in the life cycle of bacteriophagous R. orbitalis represents a strategy for surviving periods of a scarcity of bacterial food, which could be influenced by a combination of weather conditions, density of host rodents and seasonal abundance of R. orbitalis in rodent nests.

Effect of UV radiation and temperature on rheological features of multi-layer agricultural packaging foils

2008 ◽  
Vol 4 (1) ◽  
pp. 27-44 ◽  
Author(s):  
Attila Csatár ◽  
László Fenyvesi
Keyword(s):  
Uv Radiation ◽  
Environmental Temperature ◽  
Weather Conditions ◽  
Close Correlation ◽  
Relaxation Curve ◽  
Cold Weather ◽  
Transmission Properties ◽  
Warm Weather ◽  
Measured Relaxation ◽  
Maximum Transmission

The objective of the work reported here was to determine the influence of UV radiation and environmental temperature on the strength and rheological characteristics of multilayer agricultural packaging foils. The transmission properties of the experimental foils were tested in 286–363.5 nm range. The analysis of transmission properties of the foils showed that the maximum transmission was 10 % and 45 % with the experimental violet foils having 20 % and 5 % UV inhibitor in them, respectively. However, the transmission was higher than 80 % with the white foils of 5 % and 20 % inhibitor.The effect of the temperature on the tensile stress of commercial foils was investigated gated in the −20 ≤ T ≤ 50 °C temperature range. The measured relaxation curve was found to have a close correlation both for −10°C and 45°C with the calculated results. The highest reduced strength decreased as the function of the temperature according to the σ= −0,1861 T +19,107 [MPa] equation. Therefore, the probability of the break of the foils in cold weather is definitely higher than under warm weather conditions.

DROUGHT OCCURRENCE UNDER LITHUANIAN CLIMATIC CONDITIONS

2015 ◽  
Author(s):  
Laima TAPARAUSKIENĖ ◽  
Veronika LUKŠEVIČIŪTĖ
Keyword(s):  
Meteorological Data ◽  
Standardized Precipitation Index ◽  
Vegetation Period ◽  
Climatic Conditions ◽  
Precipitation Record ◽  
Calculation Step ◽  
Drought Conditions ◽  
The Standardized Precipitation Index ◽  
June July

This study provides the analysis of drought conditions of vegetation period in 1982-2014 year in two Lithuanian regions: Kaunas and Telšiai. To identify drought conditions the Standardized Precipitation Index (SPI) was applied. SPI was calculated using the long-term precipitation record of 1982–2014 with in-situ meteorological data. Calculation step of SPI was taken 1 month considering only vegetation period (May, June, July, August, September). The purpose of investigation was to evaluate the humidity/aridity of vegetation period and find out the probability of droughts occurrence under Lithuanian climatic conditions. It was found out that according SPI results droughts occurred in 14.5 % of all months in Kaunas region and in 15.8 % in Telšiai region. Wet periods in Kaunas region occurred in 15.8 %, and in Telšiai region occurrence of wet periods was – 18.8 % from all evaluated months. According SPI evaluation near normal were 69.7 % of total months during period of investigation in Kaunas and respectively – 65.5 % in Telšiai. The probability for extremely dry period under Lithuania climatic conditions are pretty low – 3.0 % in middle Lithuania and 2.4 % in western part of Lithuania.

Vulnerability of sweet cherry cultivars to continuous periods of spring frosts in Plovdiv, Bulgaria

2020 ◽  
Vol 12 (4) ◽  
pp. 348-352
Author(s):  
S. Malchev ◽  
S. Savchovska
Keyword(s):  
Sweet Cherry ◽  
Weather Conditions ◽  
Frost Damage ◽  
Cold Weather ◽  
Bud Burst ◽  
Intermediate Group ◽  
Air Temperatures ◽  
Wide Range ◽  
Group Form ◽  
Sweet Cherry Cultivars

Abstract. The periods with continuous freezing air temperatures reported during the spring of 2020 (13 incidents) affected a wide range of local and introduced sweet cherry cultivars in the region of Plovdiv. They vary from -0.6°C on March 02 to -4.9°C on March 16-17. The duration of influence of the lowest temperatures is 6 and 12 hours between March 16 and 17. The inspection of fruit buds and flowers was conducted twice (on March 26 and April 08) at different phenological stages after continuous waves of cold weather conditions alternated with high temperatures. During the phenological phase ‘bud burst’ (tight cluster or BBCH 55) some of the flowers in the buds did not develop further making the damage hardly detectable. The most damaged are hybrid El.28-21 (95.00%), ‘Van’ (91.89%) and ‘Bing’ (89.41%) and from the next group ‘Lapins’ (85.98%) and ‘Rosita’ (83.33%). A larger intermediate group form ‘Kossara’ (81.67%), ‘Rozalina’ (76.00%), ‘Sunburst’ (75.00%), ‘Bigarreau Burlat’ (69.11%) and ‘Kuklenska belitza’ (66.67%). Candidate-cultivar El.17-90 ‘Asparuh’ has the lowest frost damage values of 55.00% and El.17-37 ‘Tzvetina’ with damage of 50.60%.

Heating up trickling filters to tackle cold weather conditions

2000 ◽  
Vol 41 (1) ◽  
pp. 163-166 ◽  
Author(s):  
W. Gebert ◽  
P.A. Wilderer
Keyword(s):  
Waste Heat ◽  
Treatment Plant ◽  
Weather Conditions ◽  
Pilot Scale ◽  
Cold Weather ◽  
Filling Material ◽  
Trickling Filter ◽  
Biofilm Thickness ◽  
Trickling Filters ◽  
Biofilm Support

The investigated effects of heating the filling material in trickling filters were carried out at the Ingolstadt wastewater treatment plant, Germany. Two pilot scale trickling filters were set up. Heat exchanger pipings were embedded in the filter media of one of these trickling filters, and the temperature in the trickling filter was raised. The other trickling filter was operated under normal temperature conditions, and was used as a control. The results clearly demonstrate that the performance of trickling filters cannot be constantly improved by heating the biofilm support media. A sustained increase of the metabolic rates did not occur. The decrease of the solubility of oxgen in water and mass transfer limitations caused by an increase of the biofilm thickness are the main reasons for that. Thus, the heating of trickling filters (e.g. by waste heat utilization) in order to increase the capacity of trickling filters under cold weather conditions cannot be recommended.

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