Nutrient Removal in a 2-Stage Biological Sewage Treatment Plant

1992 ◽  
Vol 25 (4-5) ◽  
pp. 135-142
Author(s):  
E. Sickert

The Dradenau sewage treatment plant consists basically of a large activated sludge plant which supplements the treatment stages of the Köhlbrandhöft plant. Although built to mainly oxidize ammonia and despite unfavourable operating conditions - the different locations of the Köhlbrandhöft and Dradenau plants - considerable amounts of nitrogen have successfully been eliminated. Denitrification takes place in the distribution channel of the Dradenau plant and in one of the biological stages of the Köhlbrandhöft plant. This stage takes over the excess sludge from the Dradenau plant resulting in nitrifying - and denitrifying - part of the nitrogen load already here. There is an average overall reduction of 70 %. Simultaneous precipitation at the Köhlbrandhöft treatment plant reduces the phosphorus concentration in the effluent of the combined treatment plants Köhlbrandhöft/Dradenau to values recently set by legal regulations (1 mgP/l).

Author(s):  
Andrea Lanzini ◽  
Pierluigi Leone ◽  
Massimo Santarelli

A biogas coming from anaerobic digestion of urban sewage has been used to feed a SOFC planar anode-supported cell. The sewage is produced from the urban area of Torino (IT), and eventually collected and treated by SMAT (the municipal company managing the potable and waste water of the city). The biogas is produced by the thermophilic fermentation of the sludge which remains after the several treatments the sewage goes through in the above-mentioned plant. The biogas is of a high quality: it has on average a a methane content around 65% (the balance being essentially CO2), and the only significant impurity measured is H2S in a range of 70–80 ppm. The as-produced biogas has been used for feeding a planar Ni-YSZ anode-supported SOFC with a LSCF cathode. The biogas desulphurization was accomplished flowing the gas in a fixed-bed reactor, filled with activated. The fuel processing with POX has been assessed to avoid carbon deposition into the Ni-YSZ anode and convert the CH4 into H2 and CO. Short tests to check for eventual anode degradation were performed under typical operating conditions. The cell voltage was always stable under load with the tested mixtures. A cell electrical efficiency around 45% has been measured at 800°C and 80% FU. System simulations have performed as well to assess the whole system configuration under a biogas feeding. Optimization routines have been implemented to predict the best net AC efficiency achievable by a SOFC system running on biogas. Additional considerations on the management of poor LHV biogas mixture have been also assessed, showing how dry-reforming of CH4 with the CO2 already available in the biogas stream would be an excellent option needed to be investigated with further detail in the next future.


2016 ◽  
Vol 73 (9) ◽  
pp. 2268-2274 ◽  
Author(s):  
Gordon C. C. Yang ◽  
Pei-Ling Tang

In this work graphene was used for evaluation of its adsorption behavior and performance in removing phthalate esters and pharmaceuticals in municipal wastewater. Di-n-butyl phthalate (DnBP), di-(2-ethylhexyl) phthalate (DEHP), acetaminophen (ACE), caffeine (CAF), cephalexin (CLX), and sulfamethoxazole (SMX) were emerging contaminants (ECs) with detection frequencies over 92% in a one-year monitoring of the occurrence of ECs in influent samples of a sewage treatment plant in Taiwan. Thus, these ECs were selected as the target contaminants for removal by graphene adsorption process. Experimental results showed that the adsorption isotherm data were fitted well to Langmuir model equation. It was also found that the adsorption process obeyed the pseudo-second-order kinetics. A graphene dosage of 0.1 g/L and adsorption time of 12 h were found to be the optimal operating conditions for the ECs of concern in model solutions in a preliminary study. By using the determined optimal operating conditions for removal of such ECs in actual municipal wastewater, removal efficiencies for various ECs were obtained and given as follows: (1) DnBP, 89%, (2) DEHP, 86%, (3) ACE, 43%, (4) CAF, 84%, (5) CLX, 81%, and (6) SMX, 34%.


1996 ◽  
Vol 33 (12) ◽  
pp. 147-153
Author(s):  
M. Rothman ◽  
J. Hultgren

Bromma sewage treatment plant (STP) is one of three plants in Stockholm. To meet more stringent requirements for nutrient removal the plant has been extended with a final filtration stage. Earlier it has not been possible to operate the plant with nitrification during winter time. Bad settling properties of the activated sludge have led to bulking sludge and high concentrations of BOD and phosphorus in the effluent. With the filter stage it is now possible to reduce the load on the biological stage by by-passing part of the flow directly to the filters. The result has been very promising and it seems that the plant can meet the new demands for nitrogen removal without extension of the aerated volumes.


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).


1971 ◽  
Vol 6 (1) ◽  
pp. 96-114
Author(s):  
J.E. Radley ◽  
G.W. Heinke

Abstract Removal of phosphates from wastewater will become an important requirement in the near future in order to arrest the eutrophication of our surface water supplies. Present day treatment plants are inefficient in removing phosphates. Additions of new and deletions or changes in existing processes will be required. Knowledge of the concentration and type of phosphorus compound in all streams of a conventional biological treatment plant will be required to make effective and economical changes. This work attempts a mass balance on phosphorus on unit operations of two activated sludge plants: The North Toronto Sewage Treatment Plant and the Penetanguishene Sewage Treatment Plant. Preliminary field studies were carried out over several weeks to establish background information on phosphorus concentration and type at each plant. From this information, the number of sampling streams, timing of sampling, and accuracy and precision of phosphate and flow measurements for short, in-depth, phosphorus studies on each plant was made. Two 2–3 day surveys were made at each plant. The data are presented in the form of phosphorus mass balances on important unit operations as well as on the entire plant. Balances were found to be within the combined experimental error of sampling, analytical technique, and flow measurement. Major phosphate streams in decreasing order are the return sludge, raw influent, primary sludge and digestor supernatant. Present phosphorus reduction is about 20–30%, as expected for biological treatment. The possible effect of operational changes and additions of phosphorus removal process is discussed.


1992 ◽  
Vol 25 (10) ◽  
pp. 299-318 ◽  
Author(s):  
J. A. Slim ◽  
D. G. Devey ◽  
J. W. Vail

The City of Port Elizabeth designed its main sewage treatment works with water reclamation in mind and, as the reverse osmosis process, in earlier pilot plant investigations, had shown promise in its ability to produce potable water from a sewage works tertiary effluent, a full scale tubular reverse osmosis (RO) plant was installed and operated for about 12 000 hours. The investigation showed that, although renovated water of high quality can consistently be produced under normal sewage treatment plant operating conditions, using existing plant operating personnel, frequent mechanical and instrument failures indicated the need for more reliable equipment. Feed flow to the plant averaged 25 475 1/hr with a product recovery rate of 67.5%. A 13% reduction in peak standard flux occurred, indicating that membrane fouling could be controlled within acceptable limits even though the feed received no pre-treatment other than rapid sand filtration and chlorination. No abnormal degradation of the membrane was indicated. The results obtained indicated that chemically the product was of good potable quality with the possible exception of the levels of ammoniacal nitrogen, phenols and organic pollution indicators. Bacteriological quality of the product was not satisfactory but this could easily be rectified by the provision of adequate post disinfection. Daphnia pulex toxicity tests indicated that the RO product was on occasion undesirable for human consumption. The total cost of the RO product was R l.86/kl. Although the tubular RO process has great potential for producing potable water from a tertiary sewage effluent without pre-treatment, a further stage of post-treatment is probably necessary to remove micro-pollutants.


Author(s):  
Lifang Cui ◽  
Cheng Yang ◽  
Aiai Yang ◽  
Yan Sun ◽  
Fanfei Meng ◽  
...  

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