scholarly journals Method of Estimating the Carbon Footprint of Wastewater Treatment Plants

2021 ◽  
Vol 9 (1) ◽  
pp. 30
Author(s):  
Ewa Szatyłowicz ◽  
Iwona Skoczko ◽  
Paweł Puzowski

Wastewater treatment operations focus on removing pollutants from wastewater to meet water quality standards for public health and environmental protection. However, in recent decades new sustainability targets for wastewater treatment plants have been postulated and implemented, which assume that energy is one of the key elements. Therefore, a transition from a negative energy balance (energy demand covered by external sources) to an energy-neutral or unevenly positive energy balance of wastewater treatment has been postulated. The carbon footprint (CF) is a new measure of sustainability in the wastewater sector for determining the overall impact of wastewater treatment plants on climate change. The following paper presents a method for estimating and assessing the carbon footprint of wastewater treatment plants.

2017 ◽  
Vol 86 (1) ◽  
pp. 59-65
Author(s):  
Ziling Fan ◽  
Shi Shu ◽  
Chuchu Xu ◽  
Changsheng Li ◽  
Xinhuan Xiao ◽  
...  

The aim of this investigation was to determine the relationship between postpartum anoestrus and negative energy balance in an intensive dairy farm from the Heilongjiang Province, China. At 14 to 21 d after parturition, 100 cows were randomly selected and their plasma indices, including β-hydroxybutyric acid, non-esterified fatty acid, and glucose were measured. Cows were assigned to a positive energy balance group (n = 37) and a negative energy balance group (n = 36) based on their β-hydroxybutyric acid concentrations (> 1.20 mmol/l). The two groups of cows were examined by B-mode ultrasonography and rectal examination from 60 to 90 d after parturition to identify the ovarian status of oestrous and anoestrous animals. The incidences of negative energy balance and positive energy balance were 49 and 57%, respectively, from14 to 21 d after parturition. From 60 to 90 d after parturition, 94.4% of the negative energy balance group were in anoestrus and 5.6% were in oestrus, while 62.2% of the positive energy balance group were in anoestrus and 37.8% were in oestrus. Furthermore, the proportion of inactive ovaries in the negative energy balance group was 61.8%. In conclusion, the negative energy balance is an important factor causing inactive ovaries in high-yielding dairy cows.


2017 ◽  
Vol 49 (06) ◽  
pp. 472-479
Author(s):  
Tássia Borba ◽  
Lígia Galindo ◽  
Kelli Ferraz-Pereira ◽  
Raquel da Silva Aragão ◽  
Ana Toscano ◽  
...  

AbstractThe obesity epidemic has been the target of several studies to understand its etiology. The pathophysiological processes that take to obesity generally relate to the rupture of energy balance. This imbalance can result from environmental and/or endogenous events. Among the endogenous events, the hypothalamic-pituitary-adrenal axis, which promotes stress response via glucocorticoid activity, is considered a modulator of energy balance. However, it remains controversial whether the increase in plasma levels of glucocorticoids results in a positive or negative energy balance. Furthermore, there are no studies comparing different routes of administration of glucocorticoids in this context. Here, we investigated the effects of intraperitoneal (i.p.) or intracerebroventricular (i.c.v.) administration of a specific agonist for glucocorticoid receptors on food intake and energy expenditure in rats. Sixty-day old rats were treated with i.p. or i.c.v. dexamethasone. Food intake and satiety were evaluated, as well as locomotor activity in order to determine energy expenditure. Both i.p. and i.c.v. dexamethasone increased food intake and decreased energy expenditure. Moreover, i.c.v. dexamethasone delayed the onset of satiety. Together, these results confirm that central glucocorticoid signaling promotes a positive energy balance and supports the role of the glucocorticoid system as the underlying cause of psychological stress-induced obesity.


1994 ◽  
Vol 77 (1) ◽  
pp. 366-372 ◽  
Author(s):  
M. I. Goran ◽  
J. Calles-Escandon ◽  
E. T. Poehlman ◽  
M. O'Connell ◽  
E. Danforth

This study was designed to examine effects of alterations in energy balance on adaptive changes in components of total energy expenditure (TEE). Nineteen young healthy males were studied during a 10-day sedentary energy balance baseline period and then randomly assigned to one of four 10-day treatment groups: 1) no change in energy intake (EI) or physical activity (PA; energy balance at low energy flux), 2) EI increased by 50% with no change in PA (positive energy balance), 3) TEE increased by 50% by increasing PA, matched by a 50% increase in EI (energy balance at high energy flux), and 4) TEE increased by 50% by increasing PA with no change in EI (negative energy balance). TEE was measured with doubly labeled water, resting metabolic rate (RMR) by indirect calorimetry, and thermic response to feeding (TEF) by indirect calorimetry; energy expenditure of physical activity (EEPA) was estimated by subtracting RMR, TEF, and prescribed PA from TEE. TEE was significantly increased by PA (by design) but not EI. There was a significant main effect of intake and a significant intake-by-activity interaction for changes in RMR. In post hoc analysis, RMR was significantly increased during positive energy balance and energy balance at high energy flux relative to change in RMR when energy balance was maintained at low energy flux. A significant increase in RMR was also noted during negative energy balance after adjustment for change in fat-free mass. There was no significant difference in change in RMR among the three treatment groups.(ABSTRACT TRUNCATED AT 250 WORDS)


2003 ◽  
Vol 284 (1) ◽  
pp. R101-R115 ◽  
Author(s):  
Iain J. Clarke ◽  
Alexandra Rao ◽  
Yves Chilliard ◽  
Carole Delavaud ◽  
Gerald A. Lincoln

Relationship between voluntary food intake (VFI) and gene expression for appetite-regulating peptides was examined in the brains of Soay rams under contrasting photoperiods. Two groups ( n = 8) were subjected to alternating block long-day (LD) and short-day photoperiods (SD) over a period of 42 wk to entrain long-term cycles in VFI. Five animals from each group were killed 18 wk into LD or SD, and the brains were collected for in situ hybridization studies. VFI was fourfold higher under LD compared with SD. Body weight, abdominal fat, or plasma leptin levels were similar under LD and SD. LD animals were in positive energy balance and sexually inactive, and SD animals were in negative energy balance and sexually active. Neuropeptide Y (NPY) mRNA levels were higher in the arcuate nucleus (ARC) under LD, and pro-opiomelanocortin expression was lower under LD. Leptin receptor (Ob-Rb) was higher in the ARC under LD. We conclude that photoperiod-induced increase in VFI correlates with expression of NPY, but not with expression of genes for other putative orexigenic peptides. Ob-Rb gene expression is regulated by photoperiod.


2021 ◽  
pp. 1-25
Author(s):  
Xiaoping Jing ◽  
Yamin Guo ◽  
Allan Degen ◽  
Wenji Wang ◽  
Jingpeng Kang ◽  
...  

Abstract Seasonal energy intake of Tibetan sheep on the harsh Qinghai-Tibetan Plateau (QTP) fluctuates greatly and is often well below maintenance requirements. The aim of this study was to gain insight into how the hypothalamus regulates energy homeostasis in Tibetan and Small-tailed Han sheep. We compared Tibetan and Small-tailed Han sheep (n=24 of each breed), which were offered one of four diets that differed in digestible energy (DE) densities: 8.21, 9.33, 10.45 and 11.57 MJ/kg dry matter. Sheep were weighed every two weeks, and it was assumed that the change in body weight reflected the change in energy balance. The arcuate nucleus of the hypothalamus in Tibetan sheep had greater protein expressions of neuropeptide Y (NPY) and agouti-related peptide (AgRP) when in negative energy balance, but lesser protein expressions of proopiomelanocortin (POMC) and cocaine and amphetamine-regulated transcript (CART) when in positive energy balance than Small-tailed Han sheep. As a result, Tibetan sheep had a lesser body weight (BW) loss when in negative energy balance and stored more energy and gained more BW when in positive energy balance than Small-tailed Han sheep with the same dietary intake. Moreover, in the hypothalamic AMPK regulation pathway, Tibetan sheep had greater AMPKα2 protein expression than Small-tailed Han sheep, which supported the premise of a better ability to regulate energy homeostasis and better growth performance. These differences in the hypothalamic NPY/AgRP, POMC/CART and AMPK pathways between breeds conferred an advantage to the Tibetan over Small-tailed Han sheep to cope with low energy intake on the harsh QTP.


2005 ◽  
Vol 48 (5) ◽  
pp. 417-427 ◽  
Author(s):  
U. Müller ◽  
A. R. Sharifi ◽  
R. Staufenbiel ◽  
L. Hasselmann ◽  
R. Tripmacher ◽  
...  

Abstract. Fourteen pairs of identical female Holstein twins were used for a feeding trial during a period between 3rd and 21st month. One in two sibling was reared continuously at a medium (M) and the other one at a high (H) feeding intensity. Lasting diet effects of body weight (BW), back fat thickness (BFT), and milk performance (M-kg) were analyzed for the subsequent lactation. A lasting diet effect was verifiable for BFT, whereas BW don’t differ between groups. BFT indicated the changes from negative to positive energy balance 7 and 10 weeks later than BW, for M and H group, respectively. Besides, BFT showed, that the duration and dimension of negative energy balance was longer in H group than in M group. BFT difference became smaller according day of lactation and resulted in about zero at day 305 of lactation. If the groups were compared only by feeding intensity, the daily milk yield was 1.7 kg higher in M than in H group, but the difference didn’t show any significance (p=0.22). However, the tendency of superiority was completely absorbed after the addition of the covariate age at first calving (AFC) in the model. Presented date in identical twins give no indications for lasting feeding effects per se on milk performance.


1988 ◽  
Vol 64 (3) ◽  
pp. 238-245 ◽  
Author(s):  
H. R. Timmermann ◽  
J. G. McNicol

A review of the literature describing moose habitat needs is presented. The growing season is a period of positive energy balance when moose feed extensively on a variety of deciduous leaves, aquatic macrophytes and herbaceous vegetation which satisfy nutritional requirements for weight gain and development. In winter, a period of negative energy balance, food intake and metabolism are reduced to conserve energy and minimize weight loss. In addition, good moose winter habitat includes shelter from extreme temperatures, deep snow and access to secure areas to help avoid predators expecially during spring calving. Optimum habitats contain an interspersion of food and cover within traditionally used seasonal home ranges.


Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 6056 ◽  
Author(s):  
Adam Masłoń ◽  
Joanna Czarnota ◽  
Aleksandra Szaja ◽  
Joanna Szulżyk-Cieplak ◽  
Grzegorz Łagód

The improvement of energy efficiency ensuring high nutrients removal is a great concern for many wastewater treatment plants (WWTPs). The energy balance of a WWTP can be improved through the application of highly efficient digestion or its intensification, e.g., through the introduction of the co-substrates with relatively high energy potential to the sewage sludge (SS). In the present study, the overview of the energetic aspect of the Polish WWTPs was presented. The evaluation of energy consumption at individual stages of wastewater treatment along with the possibilities of its increasing was performed. Additionally, the influence of co-digestion process implementation on the energy efficiency of a selected WWTP in Poland was investigated. The evaluation was carried out for a WWTP located in Iława. Both energetic and treatment efficiency were analyzed. The energy balance evaluation of this WWTP was also performed. The obtained results indicated that the WWTP in Iława produced on average 2.54 GWh per year (7.63 GWh of electricity in total) as a result of the co-digestion of sewage sludge with poultry processing waste. A single cubic meter of co-substrates fed to the digesters yielded an average of 25.6 ± 4.3 Nm3 of biogas (between 18.3 and 32.2 Nm3/m3). This enabled covering the energy demand of the plant to a very high degree, ranging from 93.0% to 99.8% (98.2% on average). Importantly, in the presence of the co-substrate, the removal efficiency of organic compounds was enhanced from 64% (mono-digestion) to 69–70%.


2015 ◽  
Vol 75 (3) ◽  
pp. 319-327 ◽  
Author(s):  
David J. Clayton ◽  
Lewis J. James

The belief that breakfast is the most important meal of day has been derived from cross-sectional studies that have associated breakfast consumption with a lower BMI. This suggests that breakfast omission either leads to an increase in energy intake or a reduction in energy expenditure over the remainder of the day, resulting in a state of positive energy balance. However, observational studies do not imply causality. A number of intervention studies have been conducted, enabling more precise determination of breakfast manipulation on indices of energy balance. This review will examine the results from these studies in adults, attempting to identify causal links between breakfast and energy balance, as well as determining whether consumption of breakfast influences exercise performance. Despite the associations in the literature, intervention studies have generally found a reduction in total daily energy intake when breakfast is omitted from the daily meal pattern. Moreover, whilst consumption of breakfast supresses appetite during the morning, this effect appears to be transient as the first meal consumed after breakfast seems to offset appetite to a similar extent, independent of breakfast. Whether breakfast affects energy expenditure is less clear. Whilst breakfast does not seem to affect basal metabolism, breakfast omission may reduce free-living physical activity and endurance exercise performance throughout the day. In conclusion, the available research suggests breakfast omission may influence energy expenditure more strongly than energy intake. Longer term intervention studies are required to confirm this relationship, and determine the impact of these variables on weight management.


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