Combined removal of nutrients and suspended solids in a dual-media post-denitrification filter as additional process step of wastewater treatment plants

2013 ◽  
Vol 8 (2) ◽  
pp. 315-322
Author(s):  
A. Sperlich ◽  
P. Geyer ◽  
R. Gnirss ◽  
M. Barjenbruch

Operation of a pilot-scale dual-media biological filter as post-denitrification step in a municipal wastewater treatment plant was investigated for 28 months. In order to identify key design parameters, filtration rate, external carbon dosing concentration and strategy as well as backwash frequency were varied. The results show that dual-media biological filtration is able to achieve effluent concentrations of total suspended solids (TSS) ≤2 mg/L and NO3-N ≤ 5 mg/L. TSS removal also leads to a reduction of particulate bound phosphorus and chemical oxygen demand without dosing any precipitant. Soluble reactive phosphorus is required for growth of the denitrifying bacteria and reduced from 0.4 to 0.3 mg/L in the filter effluent, corresponding to approximately 0.02 g P/g NOx-N removed. Depending on NOx-N loading and carbon dosage, average denitrification rates of 0.5–1.0 kg NOx-N/m3*d were achieved in different operational phases. Seasonally varying nitrite formation and breakthrough in the filter effluent were observed and could not be controlled by adjusting carbon dosage and backwash frequency. Effective operational strategies to prevent nitrite breakthrough at NOx-N loads in the range of 1–2 kg NOx-N/m3*d and high influent O2 levels are therefore needed.

2013 ◽  
Vol 20 (1) ◽  
pp. 199-208 ◽  
Author(s):  
Marketa Julinova ◽  
Jan Kupec ◽  
Roman Slavik ◽  
Maria Vaskova

Abstract A synthetic polymer, polyvinylpyrrolidone (PVP - E 1201) primarily finds applications in the pharmaceutical and food industries due to its resistance and zero toxicity to organisms. After ingestion, the substance passes through the organism unchanged. Consequently, it enters the systems of municipal wastewater treatment plants (WWTP) without decomposing biologically during the waste treatment process, nor does it attach (through sorption) to particles of activated sludge to any significant extent, therefore, it passes through the system of a WWTP, which may cause the substance to accumulate in the natural environment. For this reason the paper investigates the potential to initiate aerobic biodegradation of PVP in the presence of activated sludge from a municipal wastewater treatment plant. The following agents were selected as the initiators of the biodegradation process - co-substrates: acrylamide, N-acethylphenylalanine and 1-methyl-2-pyrrolidone, a substance with a similar structure to PVP monomer. The biodegradability of PVP in the presence of co-substrates was evaluated on the basis of biological oxygen demand (BOD) as determined via a MicroOxymax O2/CO2/CH4 respirometer. The total substrate concentration in the suspension equaled 400 mg·dm-3, with the ratio between PVP and the cosubstrate being 1:1, while the concentration of the dry activated sludge was 500 mg·dm-3. Even though there was no occurrence of a significant increase in the biodegradation of PVP alone in the presence of a co-substrate, acrylamide appeared to be the most effective type of co-substrate. Nevertheless, a recorded decrease in the slope of biodegradation curves over time may indicate that a process of primary decomposition was underway, which involves the production of metabolites that inhibit activated sludge microorganisms. The resulting products are not identified at this stage of experimentation.


Author(s):  
T. Gehring ◽  
E. Deineko ◽  
I. Hobus ◽  
G. Kolisch ◽  
M. Lübken ◽  
...  

Abstract The uncertainty associated with the determination of load parameters, which is a key step in the design of wastewater treatment plants (WWTPs), was investigated on basis on data sets from 58 WWTPs. A further analysed aspect was the organic load variations associated with variable sewage temperatures. Data from 26 WWTPs with a high inflow sampling frequency was used to simulate scenarios to investigate the effect of lower sampling frequencies through a Monte Carlo approach. The calculation of 85-percentile values for chemical oxygen demand (COD) loadings based on only 26 samples per year is associated with a variability of up to ±18%. Approximately 90 samples per year will be necessary to reduce this uncertainty for estimation of COD loadings below 10%. Hence, a low sampling frequency can potentially lead to under- or overestimation of design parameters. Through an analogous approach, it was possible to identify uncertainties of ±11% in COD loading when weekly average data was used with 4 samples per week. Finally, a tendency of lower COD input loads with increasing temperatures was identified, with a reduction of about 1% of the average loading per degree Celsius.


2004 ◽  
Vol 39 (2) ◽  
pp. 103-112 ◽  
Author(s):  
Merv Palmer ◽  
Jack Fritz

Abstract The operating characteristics of thirteen municipal wastewater treatment plants (WWTPs) with design capacities between 50,000 and 300,000 m3/d (mean 75,000 m3/d) were studied. The treatment processes used by these plants included one biofilter (BIO); two A/O (activated sludge anaerobic and aerobic processes in sequence); four A2/O (modified A/O with anaerobic, annoxic (denitrification) and aerobic cells in sequence); three oxidation ditches (OXD); two A/B (absorption-bio-oxidation two-stage [anaerobic cell followed by aerobic cell]); and one sequencing batch reactor (SBR). The study objective was to determine whether the WWTPs were operating at design conditions, and if not, to try to identify the causes of under-performance. All the WWTPs produced a treated effluent quality which was in compliance with a few exceptions. Nine WWTPs were operating with a mean of 62% of the design hydraulic flows. Thirteen WWTPs were operating at a mean of 56% of the design five-day biochemical oxygen demand (BOD) and at 84% of the design total suspended solids (TSS) loadings. Three WWTPs received high-strength wastewater (WW) (BOD >400 mg/L), four normal-strength WW (BOD = 150 to 260 mg/L) and five received weak-strength WW (BOD <150 mg/L). WW strength appeared to be a local characteristic. The mean capital treatment plant costs for one cubic metre of WW per day was 232 USD (104 to 444 USD); consequently, between 80 and 100 MUSD capital investment in WWTPs is unused.


1987 ◽  
Vol 19 (3-4) ◽  
pp. 669-680 ◽  
Author(s):  
Gordon W. Speirs ◽  
Robert D. Hill

As part of a full-scale project to demonstrate the advantages of using automated process control in wastewater treatment plants, on-line sensors used in various control loops were calibrated and/or verified during control system commissioning and startup. The on-line measurements included liquid flow rates, air flow rates, suspended solids concentrations, and dissolved oxygen concentrations. The methods used to confirm instrument performance are presented along with results that show that several instruments were found to operate outside the manufacturers' written specifications. In addition, on-line methods which can help determine when recalibrations are required, and thereby help to reduce maintenance costs and ensure reliability, are also presented.


1999 ◽  
Vol 40 (7) ◽  
pp. 55-65 ◽  
Author(s):  
Mohamed F. Hamoda ◽  
Ibrahim A. Al-Ghusain ◽  
Ahmed H. Hassan

Proper operation of municipal wastewater treatment plants is important in producing an effluent which meets quality requirements of regulatory agencies and in minimizing detrimental effects on the environment. This paper examined plant dynamics and modeling techniques with emphasis placed on the digital computing technology of Artificial Neural Networks (ANN). A backpropagation model was developed to model the municipal wastewater treatment plant at Ardiya, Kuwait City, Kuwait. Results obtained prove that Neural Networks present a versatile tool in modeling full-scale operational wastewater treatment plants and provide an alternative methodology for predicting the performance of treatment plants. The overall suspended solids (TSS) and organic pollutants (BOD) removal efficiencies achieved at Ardiya plant over a period of 16 months were 94.6 and 97.3 percent, respectively. Plant performance was adequately predicted using the backpropagation ANN model. The correlation coefficients between the predicted and actual effluent data using the best model was 0.72 for TSS compared to 0.74 for BOD. The best ANN structure does not necessarily mean the most number of hidden layers.


2021 ◽  
Vol 6 (4) ◽  
pp. 244-250
Author(s):  
Serhii Protsenko ◽  
◽  
Mykola Kizyeyev ◽  
Olha Novytska ◽  
◽  
...  

The possibility of increasing the efficiency of municipal wastewater treatment plant (WWTP) operation by changing the flow diagram of biological wastewater treatment in aeration tanks at minimum expenses for their reconstruction is shown in the paper on the example of one of the regional centres of Ukraine. The technology of nitri-denitrification of wastewater according to the flow diagram of the two-stage modified Ludzak-Ettinger process is offered for the considered conditions. The distribution of wastewater flows and internal nitrate recycling between the individual stages of this flow diagram has been optimized in order to minimize the residual content of total nitrogen in the treated effluents. Computer dynamic modelling of biochemical processes has proved the high efficiency and reliability of the flow diagram proposed by the authors.


2020 ◽  
Vol 15 (2) ◽  
pp. 515-527
Author(s):  
L. Desa ◽  
P. Kängsepp ◽  
L. Quadri ◽  
G. Bellotti ◽  
K. Sørensen ◽  
...  

Abstract Many wastewater treatment plants (WWTP) in touristic areas struggle to achieve the effluent requirements due to seasonal variations in population. In alpine areas, the climate also determines a low wastewater temperature, which implies long sludge retention time (SRT) needed for the growth of nitrifying biomass in conventional activated sludge (CAS). Moreover, combined sewers generate high flow and dilution. The present study shows how the treatment efficiency of an existing CAS plant with tertiary treatment can be upgraded by adding a compact line in parallel, consisting of a Moving Bed Biofilm Reactor (MBBR)-coagulation-flocculation-disc filtration. This allows the treatment of influent variations in the MBBR and a constant flow supply to the activated sludge. The performance of the new 2-step process was comparable to that of the improved existing one. Regardless significant variations in flow (10,000–25,000 m3/d) and total suspended solids (TSS) (50–300 mg/L after primary treatment) the effluent quality fulfilled the discharge requirements. Based on yearly average effluent data, TSS were 11 mg/L, chemical oxygen demand (COD) 27 mg/L and total phosphorus (TP) 0.8 mg/L. After the upgrade, ammonium nitrogen (NH4-N) dropped from 4.9 mg/L to 1.3 mg/L and the chemical consumption for phosphorus removal was reduced.


2008 ◽  
Vol 57 (10) ◽  
pp. 1487-1493 ◽  
Author(s):  
S. Lindtner ◽  
H. Schaar ◽  
H. Kroiss

During a six-year period the Austrian Benchmarking System was developed. The main objectives of this benchmarking system are the development of process indicators, identification of best performance and determination of cost reduction potentials. Since 2004 this system is operated via an internet platform and automated to a large extent. Every year twenty to thirty treatment plants use the web-based access to this benchmarking platform. The benchmarking procedure comprises data acquisition, data evaluation including reporting and organised exchange of experience for the treatment plant managers. The process benchmarking method links the real costs with four defined main processes and two support processes. For wastewater treatment plants with a design capacity >100,000 PE these processes are further split up into sub-processes. For each (sub-) process the operating costs are attributed to six cost elements. The specific total yearly costs and the yearly operating costs of all (sub-)processes are related to the measured mean yearly pollution load of the plant expressed in population equivalents (PE110: 110 gCOD/d corresponding to 60 g BOD5/d)). The specific capital costs are related to the design capacity (PE). The paper shows the benchmarking results of 6 Austrian plants with a design capacity >100,000 PE representing approximately 30% of the Austrian municipal wastewater treatment plant capacity.


2018 ◽  
Vol 4 (12) ◽  
pp. 1988-1996 ◽  
Author(s):  
Yan He ◽  
Yishuang Zhu ◽  
Jinghan Chen ◽  
Minsheng Huang ◽  
Guohua Wang ◽  
...  

The tense deficiency of available land resources is becoming one of the bottlenecks in dealing with wastewater treatment plant (WWTP) management issues.


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