Full-scale in-line hydrolysis and simulation for potential energy and resource savings in activated sludge – a case study

2012 ◽  
Vol 33 (15) ◽  
pp. 1819-1825 ◽  
Author(s):  
Tobias Hey ◽  
Karin Jönsson ◽  
Jes la Cour Jansen
2013 ◽  
Vol 8 (1) ◽  
pp. 142-150 ◽  
Author(s):  
Adam Sochacki ◽  
Jakub Kubiatowicz ◽  
Joanna Surmacz-Górska ◽  
Joanna Ćwikła

In last decade the focal point of the activated sludge (AS) modelling shifted from a secondary-treatment to a plant-wide level. This new approach offers more possibilities, therefore demands more effort and expertise from a modeller. This paper presents a plant-wide approach to modelling and simulation of a full-scale AS wastewater treatment plant (WWTP). The construction and routine operational data of the full-scale Central WWTP in Gliwice (Poland) were used in this study to develop an integrated model of the water and sludge lines of the plant. The core of the plant model was the Activated Sludge Model No.1 (ASM1), which combined with sub-models of the other processes, was implemented in the WEST® Software version 3.7.6. The calibration strategy, verification and predictive capacity of the model are discussed. The calibrated model permitted acceptable accuracy of the simulation, yet limited data restrained its scope. Thus, the obtained mathematical description of the plant is a preliminary yet sound basis for a more versatile model. The model limitations and opportunities for its further applications and development are discussed.


2014 ◽  
Vol 70 (7) ◽  
pp. 1251-1260 ◽  
Author(s):  
L. J. P. Snip ◽  
R. Boiocchi ◽  
X. Flores-Alsina ◽  
U. Jeppsson ◽  
K. V. Gernaey

It is common practice in wastewater engineering to extend standard activated sludge models (ASMs) with extra process equations derived from batch experiments. However, such experiments have often been performed under conditions different from the ones normally found in wastewater treatment plants (WWTPs). As a consequence, these experiments might not be representative for full-scale performance, and unexpected behaviour may be observed when simulating WWTP models using the derived process equations. In this paper we want to highlight problems encountered using a simplified case study: a modified version of the Activated Sludge Model No. 1 (ASM1) is upgraded with nitrous oxide (N2O) formation by ammonia-oxidizing bacteria. Four different model structures have been implemented in the Benchmark Simulation Model No. 1 (BSM1). The results of the investigations revealed two typical difficulties: problems related to the overall mathematical model structure and problems related to the published set of parameter values. The paper describes the model implementation incompatibilities, the variability in parameter values and the difficulties of reaching similar conditions when simulating a full-scale activated sludge plant. Finally, the simulation results show large differences in oxygen uptake rates, nitritation rates and consequently the quantity of N2O emission (GN2O) using the different models.


PCI Journal ◽  
2015 ◽  
Vol 60 (6) ◽  
pp. 39-50 ◽  
Author(s):  
Brett Tempest ◽  
Clarke Snell ◽  
Thomas Gentry ◽  
Maria Trejo ◽  
Keith Isherwood

1996 ◽  
Vol 33 (1) ◽  
pp. 311-323 ◽  
Author(s):  
A. Witteborg ◽  
A. van der Last ◽  
R. Hamming ◽  
I. Hemmers

A method is presented for determining influent readily biodegradable substrate concentration (SS). The method is based on three different respiration rates, which can be measured with a continuous respiration meter which is operated in a cyclic way. Within the respiration meter nitrification is inhibited through the addition of ATU. Simulations were used to develop the respirometry set-up and decide upon the experimental design. The method was tested as part of a large measurement programme executed at a full-scale plant. The proposed respirometry set-up has been shown to be suitable for a semi-on-line determination of an influent SS which is fully based on the IAWQ #1 vision of the activated sludge process. The YH and the KS play a major role in the principle, and should be measured directly from the process.


1999 ◽  
Vol 40 (11-12) ◽  
pp. 223-229 ◽  
Author(s):  
Frédéric Clauss ◽  
Christel Balavoine ◽  
Delphine Hélaine ◽  
Gaëtan Martin

Forest industry wastewaters are difficult to clean: hydraulic and organic load variations, filamentous bulking or pin-point flocs negatively impact depollution processes. The addition of a fine, mineral, talc-based powder, Aquatal, into the aeration tanks of wastewater treatment plants connected to pulp and paper factories has been successfully tested since end of '97. The first case-study presents full results obtained over a period of 18 months in a 20,000 p.e. plant connected to a paper factory. The mineral powder was regularly added to control sludge volume index, thereby ensuring low suspended solids concentration in the outfluent. Plant operators could easily adapt biomass concentration to match organic load variation, thereby maintaining pollution micro-organisms ratio constant. In a second case study, a trouble-shooting strategy was implemented to counteract filamentous bulking. A one-off, large dosage enabled the plant operator to deal effectively with poor settleability sludge and rapidly control sludge blanket expansion. In both cases, the main common characteristics observed were an increase in floc aggregation and the production of heavier and well-structured flocs. The sludge settling velocity increased and an efficient solid/liquid separation was obtained. After a few days, the mineral particles of Aquatal were progressively integrated into the sludge floc structure. When the mineral powder was added to the activated sludge in the aeration basin, chemical interactions frequently encountered with other wastewater treatment additives did not pose a problem. Moreover, with this mineral additive, the biological excess sludge displayed good thickening properties and dewatering was improved. Despite the addition of the insoluble mineral particles, the amount of wet sludge expelled did not increase. Aquatal offers a rapid solution to floc settleability problems which so frequently arise when physical or biological disorders appear in forest industry wastewater treatment plants.


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