Denitrification with methanol in tertiary filtration at wastewater treatment plant Zürich-Werdhölzli

1997 ◽  
Vol 36 (1) ◽  
pp. 165-172 ◽  
Author(s):  
G. Koch ◽  
H. Siegrist

In co-ordination with the EU-guidelines the large wastewater treatment plants in Switzerland have to be extended with enhanced nitrogen removal. Denitrification in tertiary filtration is a cost-effective alternative to extended denitrification in the activated sludge system, which needs additional reactor volume. At the wastewater treatment plant Zürich-Werdhölzli full-scale experiments of denitrification with methanol in tertiary filtration were performed during a summer and a winter campaign of 4 months each. For this purpose one of the original 22 filter cells was equipped with a methanol dosage. At temperatures of 12-15°C rates of denitrification of about 1.0 kgN m−3 d−1 are attained. After main backwashing, denitrification is significantly reduced. Frequent backwashings (several times per day) led to methanol breakthroughs due to biofilm loss. The yield coefficient YCOD was 0.4 kg CODX kg−1 CODme. In spite of methanol dosage the quality of the filter effluent was very good during normal operation in the winter campaign. Accumulation of the nitrite intermediate product was observed in summer at temperatures of 20-22°C.

Processes ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 85
Author(s):  
Barbara Wodecka ◽  
Jakub Drewnowski ◽  
Anita Białek ◽  
Ewa Łazuka ◽  
Joanna Szulżyk-Cieplak

One of the important factors determining the biochemical processes in bioreactors is the quality of the wastewater inflow to the wastewater treatment plant (WWTP). Information on the quality of wastewater, sufficiently in advance, makes it possible to properly select bioreactor settings to obtain optimal process conditions. This paper presents the use of classification models to predict the variability of wastewater quality at the inflow to wastewater treatment plants, the values of which depend only on the amount of inflowing wastewater. The methodology of an expert system to predict selected indicators of wastewater quality at the inflow to the treatment plant (biochemical oxygen demand, chemical oxygen demand, total suspended solids, and ammonium nitrogen) on the example of a selected WWTP—Sitkówka Nowiny, was presented. In the considered system concept, a division of the values of measured wastewater quality indices into lower (reduced values of indicators in relation to average), average (typical and most common values), and upper (increased values) were adopted. On the basis of the calculations performed, it was found that the values of the selected wastewater quality indicators can be identified with sufficient accuracy by means of the determined statistical models based on the support vector machines and boosted trees methods.


2017 ◽  
Vol 32 (1) ◽  
pp. 31-39 ◽  
Author(s):  
Bartosz Jawecki ◽  
Katarzyna Pawęska ◽  
Marcin Sobota

Abstract The study presents the legal requirements concerning the quality of wastewater discharged to waterbodies and to soil after treatment in household wastewater treatment plants located in agglomerations or outside them. The procedure of stopping the operation of a household treatment plant that doesn’t meet the statutory wastewater treatment efficiency was presented. The decision ordering to stop the use of a household wastewater treatment plant has to be preceded by a decision ordering to take measures to limit its adverse impact on the environment. The clarification procedure has to determine the adverse impact on the environment in a doubtless manner and it has to be reflected in the documentation. The assessment of adverse impact should take into account the binding standards of use of the environment. Stopping the operation of a household wastewater treatment plant may result in issuing a decision ordering the user to connect to the sanitary sewage system.


2008 ◽  
Vol 58 (10) ◽  
pp. 1971-1976 ◽  
Author(s):  
J. S. Albuquerque ◽  
J. C. Domingos ◽  
G. L. Sant'Anna ◽  
M. Dezotti

Biosolids production in the activated sludge process generates an additional cost to wastewater treatment plants due to the growing requirements for sludge treatment and disposal. This work focuses on the application of ozonation to reduce sludge production in an industrial wastewater treatment plant. The results show that ozonation was able to promote cell wall rupture, releasing intracellular matter into the liquid medium. This effect was observed by the increase in concentrations of DNA (1.14 to 7.83 mg/L) and proteins (0.5 to 45.602 mg/L) in the liquid phase, when ozonation was applied during 10 min, using 30 mg/L of ozone. Reduction of sludge production was assessed by calculating the observed sludge yield coefficient (Y) in bench-scale continuous experiments conducted with varying proportions of ozonated sludge in the recycle stream and recycle ratios. Reduction of sludge production ranged from 14 to 39%, depending on the experimental conditions. The best result in terms of sludge excess reduction was achieved when 20% of the recycle sludge was ozonated and the recycle ratio was 0.67.


Water ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 225
Author(s):  
Liam J. Reynolds ◽  
Laura Sala-Comorera ◽  
Mohd Faheem Khan ◽  
Niamh A. Martin ◽  
Megan Whitty ◽  
...  

Wastewater surveillance is a cost-effective tool for monitoring SARS-CoV-2 transmission in a community. However, challenges remain with regard to interpretating such studies, not least in how to compare SARS-CoV-2 levels between different-sized wastewater treatment plants. Viral faecal indicators, including crAssphage and pepper mild mottle virus, have been proposed as population biomarkers to normalise SARS-CoV-2 levels in wastewater. However, as these indicators exhibit variability between individuals and may not be excreted by everyone, their utility as population biomarkers may be limited. Coprostanol, meanwhile, is a bacterial metabolite of cholesterol which is excreted by all individuals. In this study, composite influent samples were collected from a large- and medium-sized wastewater treatment plant in Dublin, Ireland and SARS-CoV-2 N1, crAssphage, pepper mild mottle virus, HF183 and coprostanol levels were determined. SARS-CoV-2 N1 RNA was detected and quantified in all samples from both treatment plants. Regardless of treatment plant size, coprostanol levels exhibited the lowest variation in composite influent samples, while crAssphage exhibited the greatest variation. Moreover, the strongest correlations were observed between SARS-CoV-2 levels and national and Dublin COVID-19 cases when levels were normalised to coprostanol. This work demonstrates the usefulness of coprostanol as a population biomarker for wastewater surveillance studies.


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.


2007 ◽  
Vol 56 (7) ◽  
pp. 21-31 ◽  
Author(s):  
D. Brdjanovic ◽  
M. Mithaiwala ◽  
M.S. Moussa ◽  
G. Amy ◽  
M.C.M. van Loosdrecht

This paper presents results of a novel application of coupling the Activated Sludge Model No. 3 (ASM3) and the Anaerobic Digestion Model No.1 (ADM1) to assess a tropical wastewater treatment plant in a developing country (Surat, India). In general, the coupled model was very capable of predicting current plant operation. The model proved to be a useful tool in investigating various scenarios for optimising treatment performance under present conditions and examination of upgrade options to meet stricter and upcoming effluent discharge criteria regarding N removal. It appears that use of plant-wide modelling of wastewater treatment plants is a promising approach towards addressing often complex interactions within the plant itself. It can also create an enabling environment for the implementations of the novel side processes for treatment of nutrient-rich, side-streams (reject water) from sludge treatment.


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.


Sign in / Sign up

Export Citation Format

Share Document