Preliminary Investigation of Primary Sludge Hydrolysis

Author(s):  
Regimantas Dauknys ◽  
Aušra Mažeikienė ◽  
Anna Haluza ◽  
Illia Halauniou ◽  
Victor Yushchenko

One of reasons of non-effective biological nutrient removal from wastewater is lack of readily biodegradable organic matter. This problem could be solved by application of sludge hydrolysis process. The conditions for hydrolysis of primary sludge could be created performing the recirculation of the primary sludge and ensuring the required sludge retention time. In the period of preliminary investigation, the following conditions were created in the primary sedimen-tation tank of Vitebsk WWTP: average sludge recirculation was 4.8 % of the inlet flowrate to the sedimentation tank and average SRT was 5 days. Obtained results showed that hydrolysis process allowed improving the ratio between organic matter and nutrients in wastewater.

2008 ◽  
Vol 3 (1) ◽  
Author(s):  
Julien Chauzy ◽  
Didier Cretenot ◽  
Anne Bausseron ◽  
Stéphane Deleris

Veolia Water has developed during these last years its own THP (Thermal Hydrolysis Process) named BIOTHELYS® in order to enhance MAD (mesophilic anaerobic digestion) of municipal or industrial sludge. The first reference BIOTHELYS® has been installed at Saumur in France, an extended aeration biological nutrient removal facility, and commissioned in April 2006. The thermal hydrolysis of dewatered sludge is realised by steam injection at a temperature of 160°C for duration of circa 30 minutes. The THP reactors are paired in order to recover flash steam and heat sludge economically. The MAD of hydrolysed sludge is done within a HRT of 15 days and reaches volatile reduction of more than 45% on extended aeration biological sludge. BIOTHELYS® turns the MAD of extended aeration biological sludge into a very attractive solution while producing green energy with biogas. MAD is thus no more only reserved for mixed sludge but also for pure biological sludge when using THP.


1996 ◽  
Vol 34 (1-2) ◽  
pp. 417-423 ◽  
Author(s):  
G. J. Hatziconstantinou ◽  
P. Yannakopoulos ◽  
A. Andreadakis

Primary sludge hydrolysis can enrich primary effluent with the soluble organics which in turn can be a valuable carbon source to subsequent nutrient removal processes. By controlling hydraulic retention time and temperature it is possible to confine the anaerobic digestion of the primary sludge to the acidogenic and acetogenic phase (hydrolysis/fermentation process), and take advantage of the soluble organics produced. This paper presents the results of a research involving bench and pilot scale experiments related to primary sludge hydrolysis. The pilot scale sedimentation tank (4.10 m in diameter, 3.20 m in depth) operated over an expended period of 21 months as a conventional clarifier and following this as a fermentor unit employing sludge recirculation. Parallel to the pilot scale experiments, several batch and continuous flow bench scale experiments were conducted in order to determine the factors controlling the production of soluble organics and the effect of the latter on the denitrification process. The conclusions drawn were that a) a soluble COD production of the order of 5-6% in terms of sludge TCOD can be expected in a batch fermentor operating with HRT≅2days at T≤ 20°C, b) in a continuous flow fermentor, combinations of T>20°C and SRT>2 should be applied in order to achieve a production of the order of 10%, c) significant soluble carbon production can be achieved in primary sedimentation tanks (over 30% in terms of influent SCOD) when relatively increased SRTs (4 to 5 days) in combination with sludge recirculation are employed, under T>22°C, and d) increased denitrification performance of the order of 9 mgNOx/g MLSS.hr, can be achieved with hydrolysate as a carbon source.


1999 ◽  
Vol 39 (6) ◽  
pp. 1-11 ◽  
Author(s):  
George A. Ekama ◽  
Mark C. Wentzel

Filamentous bulking and the long sludge age required for nitrification are two important factors that limit the wastewater treatment capacity of biological nutrient removal (BNR) activated sludge systems. A growing body of observations from full-scale plants indicate support for the hypothesis that a significant stimulus for filamentous bulking in BNR systems in alternating anoxic-aerobic conditions with the presence of oxidized nitrogen at the transition from anoxic to aerobic. In the DEPHANOX system, nitrification takes place externally allowing sludge age and filamentous bulking to be reduced and increases treatment capacity. Anoxic P uptake is exploited in this system but it appears that this form of biological excess P removal (BEPR) is significantly reduced compared with aerobic P uptake in conventional BNR systems. Developments in the understanding of the BEPR processes of (i) phosphate accumulating organism (PAO) denitrification and anoxic P uptake, (ii) fermentation of influent readily biodegradable (RB)COD and (iii) anaerobic hydrolysis of slowly biodegradable (SB)COD are evaluated in relation to the IAWQ Activated Sludge Model (ASM) No.2. Recent developments in BEPR research do not yet allow a significant improvement to be made to ASM No. 2 that will increase its predictive power and reliability and therefore it remains essentially as a framework to guide further research.


2011 ◽  
Vol 63 (7) ◽  
pp. 1446-1452 ◽  
Author(s):  
Jia-wei Wang ◽  
Tian-zhu Zhang ◽  
Ji-ning Chen ◽  
Zhi-rong Hu

Biological nutrient removal requires sufficient carbon source. Meanwhile, the removal of organic matter in wastewater requires energy consumption in the aeration tank. Carbon source for nutrient removal in most wastewater treatment plants with conventional primary clarifier (CPC) is generally insufficient in China. In order to increase carbon source and to save energy, a part of the CPC may be retrofitted as an activated primary clarifier (APC). In this paper, a pilot scale experiment was conducted to examine the performance of primary sludge fermentation and its effect on nitrogen and phosphorus removal. Results show that the primary sludge fermentation in APC has produced a similar VFA/TP ratio but a higher BOD5/TN ratio compared with those in the CPC effluent, and the TN concentrations in the secondary effluent are at 8.0, 10.8, and 17.4 mg/L, while TP is at 0.45, 1.10, and 2.28 mg/L when the pilot test system was fed with (1) the APC effluent, (2) 50% from the APC effluent and 50% from the CPC effluent, and (3) the CPC effluent, respectively. Results also indicate that the BOD5/TN ratio is a more sensitive factor than the VFA/TP ratio for nutrient removal and energy conservation for the APC fermentation.


2011 ◽  
Vol 6 (2) ◽  
Author(s):  
N. Serón ◽  
S. Puig ◽  
S.C.F. Meijer ◽  
M.D. Balaguer ◽  
J. Colprim

Excess biomass produced during the biological treatment of wastewater requires costly disposal. As environmental and legislative constraints increase, there is considerable impetus for reducing the sludge production. Nowadays, several strategies for minimizing it production are applied but high costs still limit their application in full-scale wastewater treatment plants (WWTPs). On the other hand, biological nutrient removal (BNR) process may have an impact on the sludge production. This paper deals with the effect on the organic matter and nitrogen performances on the sludge production treating urban wastewater. The results demonstrated that the sewage sludge production was reduced between 50 to 60% (0.38 to 0.16 kg VSS·kg−1 COD) while improving the nitrogen removal efficiency from 33% to 79%. Therefore, an efficient way to minimize the sludge production, it is by operating the WWTP in optimal conditions for nutrient removal.


1994 ◽  
Vol 29 (12) ◽  
pp. 41-48 ◽  
Author(s):  
J. Charlton

The Melby Wastewater Treatment Plant is located in the municipality of Frederiksværk on the island of Sealand, Denmark. This may be the first full-scale plant in Europe purpose built for biological nutrient removal from diluted wastewater, i.e. weak domestic wastewater mixed with infiltration waters. The relatively strict effluent standards have required the existing treatment plant to be upgraded in capacity, including the design for biological Nitrogen and Phosphorus removal. Due to the weak nature of the influent wastewater, the treatment process that has been adopted includes the application of a primary sludge fermenter to alter the influent characteristics suitable for biological nutrient removal. The treatment process used is the Modified University of Cape Town process utilising a primary sludge fermenter developed at the University of British Columbia in Canada. The combination of these two processes has been successfully applied to meet the strict discharge licence requirements, without the addition of chemicals, despite the unsuitable characteristics of the influent wastewater for biological nutrient removal. The paper describes the operational results for the treatment plant.


2021 ◽  
Vol 333 ◽  
pp. 12002
Author(s):  
Regina Damalerio ◽  
Aileen Orbecido ◽  
Michael Angelo Promentilla ◽  
Ramon Christian Eusebio ◽  
Liza Patacsil ◽  
...  

Water utilities, commercial and industrial establishments are required to upgrade or install new treatment systems to comply with the revised effluent standards issued by the Department of Environment and Natural Resources – Environment Management Bureau (DENR – EMB) which now includes removal and monitoring of nutrients (nitrogen and phosphorus components). One solution is to utilize a biological nutrient removal technology (BNRT) system capable of removing nutrients from sewage. The on-going study aims to investigate the performance of the pilot-scale system in the removal of nutrients from sewage. The designed pilot-scale anaerobic-anoxic-oxic (A2O) process with a total hydraulic retention time of 8.37 hrs. was operated in an existing sewage treatment plant (STP). System modification was adapted to ensure continuous operation. Dissolved oxygen (DO) and temperature of each compartment were evaluated after 45 days of system modification. The DO of the anaerobic and oxic compartment remained within the required range, while the internal recycling flowrate and/or aeration must be adjusted to achieve a DO concentration of 0.20 – 0.50 mg/L in the anoxic compartment. The research is financially supported by the Philippine Council for Industry, Energy and Emerging Technology Research and Development of the Department of Science and Technology (PCIEERD Project No. 04176).


Sign in / Sign up

Export Citation Format

Share Document