The effect of maintenance energy requirements on biomass production during wastewater treatment

1999 ◽  
Vol 33 (3) ◽  
pp. 847-853 ◽  
Author(s):  
Euan W Low ◽  
Howard A Chase
Keyword(s):  
Wastewater Treatment ◽  
Biomass Production ◽  
Energy Requirements ◽  
Maintenance Energy

The use of chemical uncouplers for reducing biomass production during biodegradation

1998 ◽  
Vol 37 (4-5) ◽  
pp. 399-402 ◽  
Author(s):  
Euan W. Low ◽  
Howard A. Chase
Keyword(s):  
Biomass Production ◽  
Cell Mass ◽  
Model System ◽  
Energy Requirements ◽  
Simultaneous Increase ◽  
Maintenance Energy ◽  
Specific Substrate ◽  
Substrate Uptake ◽  
Activated Sludge Process ◽  
Substrate Uptake Rate

Reducing the energy available for anabolism of cell mass was identified as a method to minimise disposal requirements of excess biomass produced in the activated sludge process. A model system consisting of Pseudomonas putida, maintained in a chemostat, was employed to investigate biomass production in the presence of the energy dissipating protonphore, p-nitrophenol (pNP). The efficiency of biomass production was reduced by up to 62% when the feed was supplemented with 100 mg pNP.l−1 with a simultaneous increase in the specific substrate uptake rate. The data obtained have been analysed to reveal maintenance energy requirements and true growth yields. Cells were found to satisfy their maintenance energy requirements prior to utilising energy in anabolism. Decreases in pH alone had no effect on biomass production, but caused additional protonphore induced reduction of biomass production. A pH 6.2 the efficiency of biomass production was reduced by up to 77% when the feed was supplemented with 100 mg pNP.l−1.

Municipal wastewater treatment in Berlin with deep tanks and flotation for secondary clarification

1996 ◽  
Vol 33 (12) ◽  
pp. 199-210
Author(s):  
R. Gnirss ◽  
A. Peter-Fröhlich ◽  
V. Schmidt
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Municipal Wastewater ◽  
Energy Requirements ◽  
Municipal Wastewater Treatment ◽  
Space Saving ◽  
Process Energy ◽  
Near Future ◽  
Interesting Alternative ◽  
Pilot Tests

For municipal wastewater treatment, space-saving 10m deep activated sludge tanks are an interesting alternative to conventional tanks of shallow construction. Results from pilot tests in the Berlin-Ruhleben WWTP have shown that the biological P-elimination, nutrification and denitrification processes can be implemented as in shallow tanks. However, the activated sludge did not settle satisfactorily. Flotation was implemented in the process for secondary clarification and in the meanwhile has shown to be advantageous. Tests run over a period of some years with the pilot plant have proven the feasibility of this process. Energy requirements for both systems were found to be approximately the same. A cost estimate based on a preplan revealed a 10% advantage in favour of the 10m WWTP with flotation. For these reasons, one 10m WWTP with flotation for secondary clarification and a capacity of 80,000 m3/d will be built in Berlin in the near future.

scholarly journals Determination of Maintenance Energy Requirements for Fattening Castrated Korean Black Goats (Capra hircus coreanae)

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1543
Author(s):  
Sang-Ho Moon ◽  
Yeong Sik Yun ◽  
Na Yeon Kim ◽  
Sanguk Chung ◽  
Qi Man Zhang ◽  
...  
Keyword(s):  
Body Weight ◽  
Energy Intake ◽  
Energy Levels ◽  
Average Daily Gain ◽  
Nutrient Digestibility ◽  
Metabolic Energy ◽  
Energy Requirements ◽  
Capra Hircus ◽  
Maintenance Energy ◽  
Daily Gain

Twelve adult (10 months old) castrated Korean black goats, with an average initial body weight of 24.98 ± 3.7 kg, were used in this experiment to determine their maintenance energy requirements. Dry matter intakes (g/d, p = 0.945) were not affected by energy levels, but metabolic energy intake (kcal/d, p < 0.002) and average daily gain (g/d, p < 0.001) were significantly increased at higher energy levels. Nutrient digestibility was similar in the treatments, but crude fat digestibility increased with the addition of protective fat powder (p = 0.001). The energy required for fattening the castrated Korean black goats was estimated using the correlation between metabolic energy intake per dietary body weight and average daily gain per dietary body weight. The Y-axis intercept value was calculated to be 108.76 kcal/kg BW0.75 (p < 0.05, r2 = 0.6036), which was the metabolic energy requirement for maintaining the lives of the fattening Korean black goats. The estimated energy requirements of the black goat can improve specification techniques, such as the energy level and the amount of feed supply required for domestic black goats.

scholarly journals A Cyanobacteria-Based Biofilm System for Advanced Brewery Wastewater Treatment

2020 ◽  
Vol 11 (1) ◽  
pp. 174
Author(s):  
Konstantinos P. Papadopoulos ◽  
Christina N. Economou ◽  
Athanasia G. Tekerlekopoulou ◽  
Dimitris V. Vayenas
Keyword(s):  
Wastewater Treatment ◽  
Biomass Production ◽  
Low Cost ◽  
Oxygen Demand ◽  
Dry Weight ◽  
Surface Hydrophobicity ◽  
Reactor Performance ◽  
Brewery Wastewater ◽  
Kjeldahl Nitrogen ◽  
Supporting Materials

Algal/cyanobacterial biofilm photobioreactors provide an alternative technology to conventional photosynthetic systems for wastewater treatment based on high biomass production and easy biomass harvesting at low cost. This study introduces a novel cyanobacteria-based biofilm photobioreactor and assesses its performance in post-treatment of brewery wastewater and biomass production. Two different supporting materials (glass/polyurethane) were tested to investigate the effect of surface hydrophobicity on biomass attachment and overall reactor performance. The reactor exhibited high removal efficiency (over 65%) of the wastewater’s pollutants (chemical oxygen demand, nitrate, nitrite, ammonium, orthophosphate, and total Kjeldahl nitrogen), while biomass per reactor surface reached 13.1 and 12.8 g·m−2 corresponding to 406 and 392 mg·L−1 for glass and polyurethane, respectively, after 15 days of cultivation. The hydrophilic glass surface favored initial biomass adhesion, although eventually both materials yielded complete biomass attachment, highlighting that cell-to-cell interactions are the dominant adhesion mechanism in mature biofilms. It was also found that the biofilm accumulated up to 61% of its dry weight in carbohydrates at the end of cultivation, thus making the produced biomass a suitable feedstock for bioethanol production.

Maintenance energy requirements of grazing sheep: A detailed comparison between models

1984 ◽  
Vol 15 (1) ◽  
pp. 1-22 ◽  
Author(s):  
Daniel Wallach ◽  
Jean Michel Elsen ◽  
Jean Louis Charpenteau
Keyword(s):  
Detailed Comparison ◽  
Energy Requirements ◽  
Maintenance Energy ◽  
Grazing Sheep

scholarly journals Measurement of Energy Production from Biogas: Evidence from the Wastewater Treatment Plant in Durres

2020 ◽  
Vol 5 (10) ◽  
pp. 1260-1262
Author(s):  
Stela Sefa ◽  
Tania Floqi ◽  
Julian Sefa
Keyword(s):  
Energy Efficiency ◽  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Energy Production ◽  
Biogas Production ◽  
Treatment Plant ◽  
Electricity Consumption ◽  
Waste To Energy ◽  
Energy Requirements ◽  
Daily Consumption

The wastewater treatment plant serving the city of Durres, which is the second most populous city of Albania, employs the tertiary advanced wastewater treatment method and engages in biogas production to achieve energy efficiency. In order to empirically evaluate the plant’s energy efficiency realization, the total biogas produced and converted to electricity for daily consumption was measured during a three years period (2016 - 2018). The highest electricity produced was recorded in 2016, with a daily average of 844kWh compared to 550kWh and 370kWh in 2017 and 2018, respectively. So that the plant meets proper criteria to classify as an energy-efficient entity, 30.0 percent of its electricity consumption must be derived from biogas. Converted in kWh, the plant should generate 2,975 kWh/day. Based on the biomass and energy values measured during the study period, it is concluded that electricity supplied from biogas met 6.0 percent of the plant’s energy requirements, or one fifth of the energy-efficiency target. While the plant was successful in carrying out the full waste-to-energy production process, the electricity supplied from biogas was very low and did not fulfil the plant’s self-energy requirements.

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