Hydrolysis of return sludge for production of easily biodegradable carbon: effect of pre-treatment, sludge age and temperature

2006 ◽  
Vol 53 (12) ◽  
pp. 47-54 ◽  
Author(s):  
K. Jönsson ◽  
J. la C. Jansen

Return sludge from two Swedish and two Danish wastewater treatment plants were hydrolysed in laboratory reactors. Treatment plants with/without pre-sedimentation and with/without nitrification were represented. Soluble organic matter was produced from all types of sludge, but the yield was to a large extent dependent on what type of sludge was hydrolysed. Activated sludge from wastewater treatment plants without pre-treatment returned more soluble carbon after hydrolysis than sludge from treatment plants with pre-sedimentation. In addition, more soluble carbon was formed from non-nitrifying activated sludge than from nitrifying sludge. Moreover, the maximum yield of soluble COD at 10 °C was less than the yield at 20 °C. The initial hydrolysis rate was found to be between 0.35 and 1.8 mg soluble COD/(g VS × h). With the exception of one case, between 15 and 50% of the produced soluble COD was shown to be volatile fatty acids, a suitable carbon source for biological phosphorus removal. Nitrification rate measurements indicated that the viability of the activated sludge was not affected by the hydrolysis.

1994 ◽  
Vol 30 (2) ◽  
pp. 165-174 ◽  
Author(s):  
Ralf Otterpohl ◽  
Thomas Rolfs ◽  
Jörg Londong

Computer simulation of activated sludge plant for nitrogen removal has become a reliable tool to predict the behaviour of the plant Models including biological phosphorus removal still require some practical experience but they should be available soon. This will offer an even wider range than today's work with nitrogen removal. One major benefit of computer simulation of wastewater treatment plants (WTP) is the optimization of operation. This can be done offline if hydrographs of a plant are collected and computer work is done with “historical” analysis. With online simulation the system is fed with hydrographs up to the actual time. Prognosis can be done from the moment of the computer work based on usual hydrographs. The work of the authors shows how accuratly a treatment plant can be described, when many parameters are measured and available as hydrographs. A very careful description of all details of the special plant is essential, requiring a flexible simulation tool. Based on the accurate simulation a wide range of operational decisions can be evaluated. It was possible to demonstrate that the overall efficiency in nitrogen removal and energy consumption of ml activated sludge plant can be improved.


2001 ◽  
Vol 44 (1) ◽  
pp. 49-56 ◽  
Author(s):  
M. Wichern ◽  
F. Obenaus ◽  
P. Wulf ◽  
K.-H. Rosenwinkel

In 1999 the Activated Sludge Model no. 3 (ASM 3) by the IWA task Group on Mathematical Modeling for Design and Operation of Biological Wastewater Treatment was presented. The model is used for simulation of nitrogen removal. On the basis of a new calibration of the ASM 3 with the easy degradable COD measured by respiration simulation runs of this paper have been done. In 2000 a biological phosphorus removal module by the EAWAG was added to the calibrated version of ASM 3 and is now serving the current requirements for modelling the enhanced biological P-removal. Only little experiences with different load situations of large-scale wastewater treatment plants were made with both new models so far. This article reports the experiences with the simulation and calibration of the biological parameters using ASM 3 and the EAWAG BioP Module. Three different large-scale wastewater treatment plants in Germany with different treatment systems will be discussed (Koblenz: pre-denitrification; Hildesheim: simultaneous denitrification with EBPR; Duderstadt: intermediate denitrification with EBPR). Informations regarding the choice of kinetic and stoichiometric parameters will be given.


1998 ◽  
Vol 38 (4-5) ◽  
pp. 69-77 ◽  
Author(s):  
M. Kabacinski ◽  
B. Hultman ◽  
E. Plaza ◽  
J. Trela

Advanced process technology has been implemented at newly built wastewater treatment plants in Central and Eastern Europe. The wastewater treatment plant (WWTP) in Nowy Targ, Poland, the largest in Europe based on sequencing batch reactor (SBR) technology, has shown that newly constructed plants must be integrated into the system of water, wastewater, and sludge management in the city and the region. A significant supply of tannery wastewater with increasing chromium concentrations in the influent to the WWTP has resulted in many operational problems related mainly to sludge treatment. Evaluation of the process performance and sludge handling for 2 years of plant operation is presented. Efficient biological phosphorus removal with concentrations lower than 1 mg/l in effluent is obtained. Nitrogen removal is characterised by a low nitrification rate and a high denitrification rate. Problems with sludge handling are related to high excess sludge production, insufficient sludge stabilisation, low sludge dewatering efficiency and high chromium content in the sludge. Different strategies for sludge handling improvement are discussed. Sludge should be treated as a resource, which is recirculating in an eco-cycle with recovery of nutrients and energy. Such a process is proposed for the WWTP in Nowy Targ.


Proteomes ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 16 ◽  
Author(s):  
Herbst ◽  
Dueholm ◽  
Wimmer ◽  
Nielsen

The activated sludge in wastewater treatment plants (WWTP) designed for enhanced biological phosphorus removal (EBPR) experiences periodically changing nutrient and oxygen availability. Tetrasphaera is the most abundant genus in Danish WWTP and represents up to 20–30% of the activated sludge community based on 16S rRNA amplicon sequencing and quantitative fluorescence in situ hybridization analyses, although the genus is in low abundance in the influent wastewater. Here we investigated how Tetrasphaera can successfully out-compete most other microorganisms in such highly dynamic ecosystems. To achieve this, we analyzed the physiological adaptations of the WWTP isolate T. elongata str. LP2 during an aerobic to anoxic shift by label-free quantitative proteomics and NMR-metabolomics. Escherichia coli was used as reference organism as it shares several metabolic capabilities and is regularly introduced to wastewater treatment plants without succeeding there. When compared to E. coli, only minor changes in the proteome of T. elongata were observed after the switch to anoxic conditions. This indicates that metabolic pathways for anaerobic energy harvest were already expressed during the aerobic growth. This allows continuous growth of Tetrasphaera immediately after the switch to anoxic conditions. Metabolomics furthermore revealed that the substrates provided were exploited far more efficiently by Tetrasphaera than by E. coli. These results suggest that T. elongata prospers in the dynamic WWTP environment due to adaptation to the changing environmental conditions.


2019 ◽  
Author(s):  
Florian-Alexander Herbst ◽  
Morten S. Dueholm ◽  
Reinhard Wimmer ◽  
Per Halkjær Nielsen

AbstractThe activated sludge in wastewater treatment plants (WWTP) designed for enhanced biological phosphorus removal (EBPR) experiences periodically changing nutrient and oxygen availability. Tetrasphaera is the most abundant genus in Danish WWTP and represent up to 20-30% of the activated sludge community based on 16S rRNA amplicon sequencing and quantitative fluorescence in situ hybridization analyses, although it is in low abundance in the influent wastewater. Here we investigate how Tetrasphaera can successfully out-compete most other microorganisms in such highly dynamic ecosystems. To achive this, we analyze the physiological adaptations of the WWTP isolate T. elongata str. LP2 during an aerobic to anoxic shift by label-free quantitative proteomics and NMR-metabolomics. Escherichia coli was used as reference organism as it shares several metabolic capabilities and is regularly introduced to wastewater treatment plants, but without succeeding there. When compared to E. coli, only minor changes in the proteome of T. elongata were observed after the switch to anoxic conditions. This indicates that metabolic pathways for anaerobic energy harvest were already expressed during the aerobic growth. This allows continuous growth of Tetrasphaera immediately after the switch to anoxic conditions. Metabolomics furthermore revealed that the substrates provided were exploited far more efficiently by Tetrasphaera than by E. coli. These results suggest that T. elongata prosper in the dynamic WWTP environment due to adaptation to the changing environmental conditions.Significance of the studyMembers of the genus Tetrasphaera are widely distributed and highly abundant in most well-operating WWTPs with EBPR configuration. However, despite their high abundance in situ, little is known about their physiology and ecological role. Although the importance of Tetrasphaera in engineered wastewater treatment systems is slowly being recognized, additional information is needed to understand the full extent of functions the microorganisms have in many of the essential biological processes in the WWTP. Such information may improve available process models and ultimately lead to better wastewater treatment as well as resource recovery. This study supplies proteomic and metabolomic data on the aerobic/anoxic adaptation of Tetrasphaera and provides a hypothesis on how Tetrasphaera might compete in dynamic engineered systems.


1991 ◽  
Vol 26 (4) ◽  
pp. 475-494
Author(s):  
Lise Raymond ◽  
Yves Comeau ◽  
Jean F. Riel ◽  
François G. Brière

Abstract A weighted rating system to evaluate the feasibility of implementing biological phosphorus removal to wastewater treatment plants was developed and applied to identify the most promising existing Quebec plants using activated sludge that may benefit from this advanced technology. Three main categories of criteria were considered, (A) phosphorus discharge standards, (B) influent and effluent characteristics and (C) process characteristics. The percentage of the total weight attributed to each category was 12%, 29% and 59%, respectively. The most important factors were proposed to be the plant flexibility and configuration, the influent BOD5/TP and TKN/COD ratios, the existence of a primary clarifier, the requirements to comply with phosphorus standards, the presence of a sand filter and the possibility of mixing without air entrainment the zones of the process that should not be aerated. Among the 16 activated sludge plants for which operating data was available for 1989, 9 showed an interesting potential for conversion to biological phosphorus removal (6 with aeration tanks, 1 with oxidation ditches and 2 with sequencing batch reactors). Operation and construction modifications were proposed to convert these 9 plants to biological phosphorus removal and the rating system was used to assess the beneficial effect of the proposed modifications. A preliminary cost estimate performed on 7 of these plants indicated that conversion costs to biological phosphorus removal were either negligible (4 or 5 plants) or comparable to the present value of the cost of chemicals over a 20-year period (2 plants). With these conversions, biological phosphorus removal could replace partially or completely chemical phosphorus precipitation, depending on the phosphorus standards, wastewater and plant characteristics.


2003 ◽  
Vol 47 (11) ◽  
pp. 211-218 ◽  
Author(s):  
M. Wichern ◽  
M. Lübken ◽  
R. Blömer ◽  
K.-H. Rosenwinkel

In 1999, the Activated Sludge Model No. 3 by the IWA Task Group on Mathematical Modelling for the Design and Operation of Biological Wastewater Treatment was presented. The model is used for the simulation of nitrogen removal. The simulations in this paper were done on the basis of a new calibration of the ASM 3 by Koch et al., with the easily degradable COD measured by respiration. For modelling of EBPR the BioP-Module of Rieger et al., was used. Six German wastewater treatment plants were simulated during this research to test the existing set of parameters of the models on various large scale plants. It was shown that changes for nitrification and enhanced biological phosphorus removal in the set of biological parameters were necessary. Sensible parameters and recommended values are presented in this article. Apart from the values of the changed biological parameters, we will in our examination discuss the modelling of the different activated sludge systems and the influent fractioning of the COD. Two plants with simultaneous denitrification in the recirculation ditch (EBPR) are simulated, one with preliminary dentrification, one with intermittent denitrification (EBPR), one with cascade denitrification (EBPR), and one pilot plant according to the Johannesburg-process (EBPR) which was simulated over a period of three months.


2020 ◽  
Vol 15 (2) ◽  
pp. 142-151
Author(s):  
Peter Lukac ◽  
Lubos Jurik

Abstract:Phosphorus is a major substance that is needed especially for agricultural production or for the industry. At the same time it is an important component of wastewater. At present, the waste management priority is recycling and this requirement is also transferred to wastewater treatment plants. Substances in wastewater can be recovered and utilized. In Europe (in Germany and Austria already legally binding), access to phosphorus-containing sewage treatment is changing. This paper dealt with the issue of phosphorus on the sewage treatment plant in Nitra. There are several industrial areas in Nitra where record major producers in phosphorus production in sewage. The new wastewater treatment plant is built as a mechanicalbiological wastewater treatment plant with simultaneous nitrification and denitrification, sludge regeneration, an anaerobic zone for biological phosphorus removal at the beginning of the process and chemical phosphorus precipitation. The sludge management is anaerobic sludge stabilization with heating and mechanical dewatering of stabilized sludge and gas management. The aim of the work was to document the phosphorus balance in all parts of the wastewater treatment plant - from the inflow of raw water to the outflow of purified water and the production of excess sludge. Balancing quantities in the wastewater treatment plant treatment processes provide information where efficient phosphorus recovery could be possible. The mean daily value of P tot is approximately 122.3 kg/day of these two sources. The mean daily value of P tot is approximately 122.3 kg/day of these two sources. There are also two outflows - drainage of cleaned water to the recipient - the river Nitra - 9.9 kg Ptot/day and Ptot content in sewage sludge - about 120.3 kg Ptot/day - total 130.2 kg Ptot/day.


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