Examples of energy self-sufficient municipal nutrient removal plants

2011 ◽  
Vol 64 (1) ◽  
pp. 1-6 ◽  
Author(s):  
O. Nowak ◽  
S. Keil ◽  
C. Fimml
Keyword(s):  
Organic Matter ◽  
Particulate Organic Matter ◽  
Nutrient Removal ◽  
Energy Efficient ◽  
Aeration Tank ◽  
Sludge Digestion ◽  
Self Sufficiency ◽  
And Control ◽  
Aerobic Sludge ◽  
Aeration Control

In Austria, two municipal WWTPs (the Strass TP and Wolfgangsee-Ischl TP) operated with nutrient removal and aerobic sludge digestion are now energy self-sufficient. This is the result of a long-standing and on-going optimisation process at both plants including optimal aeration control and control of the aerobic section of the aeration tank to optimise denitrification and prevent degradation of particulate organic matter that should be degraded in the digester. Both TPs are now equipped with energy-efficient CHP units. However, it is maybe more sustainable to use the biogas as bio-methane/bio-fuel than in conventional CHP at the WWTP. It is shown that energy self-sufficiency should be in reach at other municipal WWTPs, too.

scholarly journals Enhancement of performance and biodegradability kinetics of aerobic-anaerobic sludge digestion

2020 ◽  
Vol 167 ◽  
pp. 01010 ◽  
Author(s):  
Boonchai Wichitsathian ◽  
Jareeya Yimratanabovorn ◽  
Watcharapol Wonglertarak
Keyword(s):  
Organic Matter ◽  
Removal Efficiency ◽  
Aeration Rate ◽  
Anaerobic Sludge ◽  
Sludge Reduction ◽  
Excess Sludge ◽  
Sludge Digestion ◽  
Anaerobic Sludge Digestion ◽  
Aerobic Sludge ◽  
Biodegradable Organic Matter

The excess sludge problem from a wastewater treatment plant is a great concerned due to the high cost of sludge management accounting for about 20% to 50% of the total operating cost. Therefore, sludge reduction is critical. Currently, aerobic and/or anaerobic sludge digestions are widely used in the industries for treating the excess sludge. The objective of this research was to study the effects of aeration rate and temperature on the excess sludge reduction by using the aerobic-anaerobic digestion system in the laboratory. The aeration rates of 1.0, 0.5, and 0.1 volume air per volume slurry per minute (vvm) at the room temperature and the thermophilic temperature (55 ± 2°C) were investigated. The results showed that the highest removal efficiency of aerobic sludge digestion was obtained at the thermophilic temperature and aeration rate of 1.0 vvm. The removal efficiency of organic matter in terms of COD, total solids (TS) and volatile solids (VS) were 34.76%, 33.01% and 43.45%, respectively. Consequently, the highest specific growth rate of microorganisms was 0.39 per hour and the substrate removal rate was 0.55 milligram CODremoved per milligram VSS per hour. Furthermore, slowly biodegradable organic matter was hydrolyzed to readily biodegradable organic matter and inert soluble organic matter. When the sludge effluent from aerobic sludge digestion was feed to the anaerobic sludge digestion, the removal efficiency of organic matter in terms of COD, TS and VS were increased by 25%, 17% and 28%, respectively. Moreover, the obtained methane production rate in the anaerobic sludge digestion was approximate 0.234 m3/kg COD removed.

Reactive tracers reveal hydraulic and control instabilities in full-scale activated sludge plant

2008 ◽  
Vol 57 (7) ◽  
pp. 1001-1007 ◽  
Author(s):  
D. Braun ◽  
W. Gujer
Keyword(s):  
Large Scale ◽  
Oxygen Sensor ◽  
Electrochemical Sensors ◽  
Aeration Tank ◽  
Control Loop ◽  
Reactive Tracers ◽  
And Control ◽  
Present Case Study ◽  
Aeration Control

The hydraulic characteristics of aeration tanks in WWTPs have a major impact on the degradation of pollutants, as well as on the control of the aeration. In particular in long reactors, which are not separated by baffles, hydraulic shortcuts or large scale recirculation can lead to a loss of performance. This work demonstrates that reactive tracers such as ammonium and oxygen can be used to investigate the hydraulics of aeration tanks in detail. With the use of electrochemical sensors it is possible to investigate effects in a broad range of time scales. In the present case study a slow oscillation of the aeration control loop was investigated. Large scale recirculation in the aeration tank and fast fluctuations of the ammonium concentrations close to the oxygen sensor were identified as the cause of these oscillations. Both, the recirculation as well as the fluctuation of the ammonium have a substantial influence on the performance of the aeration tank and the aeration control loop.

Use of ORP for Monitoring and Control of Aerobic Sludge Digestion

1990 ◽  
Vol 116 (3) ◽  
pp. 461-471 ◽  
Author(s):  
Craig C. Peddie ◽  
Donald S. Mavinic ◽  
Christopher J. Jenkins
Keyword(s):  
Monitoring And Control ◽  
Sludge Digestion ◽  
And Control ◽  
Aerobic Sludge

scholarly journals Effects of ageing under field conditions on soil organic matter in earthworm casts produced by the anecic earthworm Amynthas adexilis in northern Vietnam

2021 ◽  
Author(s):  
Nicolas Jean Bernard Puche ◽  
Cornelia Rumpel ◽  
Nicolas Bottinelli
Keyword(s):  
Organic Matter ◽  
Particulate Organic Matter ◽  
Soil Aggregates ◽  
Ct Images ◽  
Field Conditions ◽  
Strong Positive Correlation ◽  
Micro Ct ◽  
Earthworm Casts ◽  
Biogeochemical Models ◽  
And Control

<p>Carbon sequestration in soils became a major issue that governments have to face under their sustainable development objectives and the international 4p1000 program. Although, earthworms are recognized to play a key role in the structure and dynamics of organic matter (OM) in soils, their contribution to soil OM cycling is not taken into account in biogeochemical models nor well understood. In particular, the fate of OM protected in earthworm casts is unknown. In this study, we investigated the effects of ageing under field conditions on the OM dynamics contained in casts produced by the anecic earthworm Amynthas adexilis in North Vietnam. To this end we investigated (1) the microscale organisation of particulate organic matter and pores during the exposure of casts and control aggregates during 12 months and (2) compared it to the potential OM mineralisation during a laboratory incubation.</p><p>Our results indicated that fresh casts contained significantly more particulate organic matter (POM) than control soil aggregates and field aged earthworm casts. Conversely, the porosity was higher in soil control aggregates than in casts and the porosity of casts tended to increase with their ageing. The analyses of micro-CT images also revealed that POM and Pores contents between casts samples presented strong variabilities even in the youngest casts category. We found, on average, higher mineralisation rates for casts than for controls and a reduction of the OM mineralisation with the ageing of casts. Our results also highlighted a strong positive correlation (r<sup>2</sup> = 0.89) between POM contents determined by the segmentation of micro CT images and CO<sub>2</sub> emissions from the incubation experiment. We conclude that earthworms impact the microscale organisation of POM and pores in their casts and thereby influence soil OM dynamics.</p>

Relating particulate organic matter-nitrogen (POM-N) and non-POM-N with pulse crop residues, residue management and cereal N uptake

Agronomie ◽  
2002 ◽  
Vol 22 (7-8) ◽  
pp. 777-787 ◽  
Author(s):  
Graeme D. Schwenke ◽  
Warwick L. Felton ◽  
David F. Herridge ◽  
Dil F. Khan ◽  
Mark B. Peoples
Keyword(s):  
Organic Matter ◽  
Particulate Organic Matter ◽  
Crop Residues ◽  
N Uptake ◽  
Residue Management ◽  
Pulse Crop

CONCEPTUAL POSITIONS OF MODERNIZATION OF EXISTING INEFFICIENT DISTRICT HEATING SYSTEMS

2017 ◽  
pp. 11-21
Author(s):  
Ye.Ye. Nikitin
Keyword(s):  
Energy Efficient ◽  
Mutual Influence ◽  
District Heating ◽  
Current Status ◽  
Cognitive Approach ◽  
Heating Systems ◽  
Energy Management Systems ◽  
Current State ◽  
Self Sufficiency ◽  
District Heating Systems

The current situation in the sphere of district heating is analysed on the basis of use of the cognitive approach. The presence of closed chains of cause-effect relationships of negative factors and conflicts of target settings of the subjects in the field of district heating is shown. The conceptual model of energy efficient modernization of district heating systems is proposed. This model includes indicators of the current status of heat sources, networks and heat consumers, energetic and economic models, restrictions, procedure of forming and analysis of the mutual influence of the recommended projects. The quantitative data on indicators of the current state of district heating systems of the cities of Ukraine are presented. The interrelation between indicators of the current state and projects of energy efficient modernization of district heating systems is shown. Assessment of energy self-sufficiency of municipal district heating systems on condition of thermal modernization of buildings is carried out. The creation of energy management systems at the district heating enterprises is proposed. Bib. 6, Fig. 7, Tab. 5.

Macrophyte-derived detritus in shallow coastal waters contributes to suspended particulate organic matter and increases growth rates of Mytilus edulis

2020 ◽  
Vol 644 ◽  
pp. 91-103
Author(s):  
D Bearham ◽  
MA Vanderklift ◽  
RA Downie ◽  
DP Thomson ◽  
LA Clementson
Keyword(s):  
Organic Matter ◽  
Mytilus Edulis ◽  
Particulate Organic Matter ◽  
Coastal Waters ◽  
Gill Tissue ◽  
Suspension Feeder ◽  
Food Sources ◽  
Suspension Feeders ◽  
Blue Mussels ◽  
Suspended Particulate

Benthic suspension feeders, such as bivalves, potentially have several different food sources, including plankton and resuspended detritus of benthic origin. We hypothesised that suspension feeders are likely to feed on detritus if it is present. This inference would be further strengthened if there was a correlation between δ13C of suspension feeder tissue and δ13C of particulate organic matter (POM). Since detritus is characterised by high particulate organic matter (POC):chl a ratios, we would also predict a positive correlation between POM δ13C and POC:chl a. We hypothesised that increasing depth and greater distance from shore would produce a greater nutritional reliance by experimentally transplanted blue mussels Mytilus edulis on plankton rather than macrophyte-derived detritus. After deployments of 3 mo duration in 2 different years at depths from 3 to 40 m, M. edulis sizes were positively correlated with POM concentrations. POC:chl a ratios and δ13C of POM and M. edulis gill tissue decreased with increasing depth (and greater distance from shore). δ13C of POM was correlated with δ13C of M. edulis. Our results suggest that detritus comprised a large proportion of POM at shallow depths (<15 m), that M. edulis ingested and assimilated carbon in proportion to its availability in POM, and that growth of M. edulis was higher where detritus was present and POM concentrations were higher.

Hydrolysis of organic wastewater particles in laboratory scale and pilot scale biofilm reactors under anoxic and aerobic conditions

1998 ◽  
Vol 38 (8-9) ◽  
pp. 179-188 ◽  
Author(s):  
K. F. Janning ◽  
X. Le Tallec ◽  
P. Harremoës
Keyword(s):  
Organic Matter ◽  
Mass Balance ◽  
Particulate Organic Matter ◽  
Removal Rate ◽  
Pilot Scale ◽  
Laboratory Scale ◽  
Synthetic Wastewater ◽  
Aerobic Conditions ◽  
Biofilm Reactors ◽  
Hydrolysis Of

Hydrolysis and degradation of particulate organic matter has been isolated and investigated in laboratory scale and pilot scale biofilters. Wastewater was supplied to biofilm reactors in order to accumulate particulates from wastewater in the filter. When synthetic wastewater with no organic matter was supplied to the reactors, hydrolysis of the particulates was the only process occurring. Results from the laboratory scale experiments under aerobic conditions with pre-settled wastewater show that the initial removal rate is high: rV, O2 = 2.1 kg O2/(m3 d) though fast declining towards a much slower rate. A mass balance of carbon (TOC/TIC) shows that only 10% of the accumulated TOC was transformed to TIC during the 12 hour long experiment. The pilot scale hydrolysis experiment was performed in a new type of biofilm reactor - the B2A® biofilter that is characterised by a series of decreasing sized granular media (80-2.5 mm). When hydrolysis experiments were performed on the anoxic pilot biofilter with pre-screened wastewater particulates as carbon source, a rapid (rV, NO3=0.7 kg NO3-N/(m3 d)) and a slowler (rV, NO3 = 0.3 kg NO3-N/(m3 d)) removal rate were observed at an oxygen concentration of 3.5 mg O2/l. It was found that the pilot biofilter could retain significant amounts of particulate organic matter, reducing the porosity of the filter media of an average from 0.35 to 0.11. A mass balance of carbon shows that up to 40% of the total incoming TOC accumulates in the filter at high flow rates. Only up to 15% of the accumulated TOC was transformed to TIC during the 24 hour long experiment.

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