Upgrading and nitrification by submerged bio-film reactors - experiences from a large scale plant

1994 ◽  
Vol 29 (10-11) ◽  
pp. 167-174 ◽  
Author(s):  
T. H. Lessel

The upgrading and nitrification was a requirement in 1986 for the conventional sewage treatment plant Geiselbullach, west of Munich, Germany, designed for 250 000 inhabitants equivalents. The possibility was tested to use submerged bio-film reactors in the aeration tanks to increase the MLSS concentration. Half-scale experiments were undertaken with three different reactor types. A rope type material, called Ring-laceR was selected for the large-scale application, because it did not produce anaerobic sludge deposits, as the other tested reactor types did. The design criteria had to be developed. The process operation started in January 1988; a few months later the phosphorus removal by chemical precipitation was also put into operation. After stable conditions were assured the concentration of the MLSS could be increased to about 10 g/l, due to sludge volume indices of about 50, formerly 180 to 300. A nearly complete nitrification was achieved, which could even be continued in winter times at water temperatures of 8 to 10 °C. Many highly developed microorganisms in the sessile sludge occurred (nematodes, tubifex…), which grew excessively under certain conditions and reduced the normal bacteria to unacceptable low quantities. A worm cure could reduce the worms to acceptable counts. Problems with the longtime stability of the material arose and were investigated.

1994 ◽  
Vol 29 (12) ◽  
pp. 279-282 ◽  
Author(s):  
C. Güldner ◽  
W. Hegemann ◽  
N. Peschen ◽  
K. Sölter

The integration of the chemical precipitation unit which would inject a lime solution into a series of mechanical-biological processes, including nitrification/denitrification, and the sludge treatment are the subject of this project. The essential target is the large-scale reconstruction of a mechanical-biological sewage treatment plant with insufficient cleaning performance in the new German states and the adjustment of the precipitation stage to the unsteady inflow of sewage. First results indicate that the pre-treatment performance could be improved by ≅ 20% and the discharge of concentrations of COD, BOD, N and P could be reduced and homogenized. In addition, experiments on hydrolysis and acidifiability of the pre-treatment sludge have been carried out on a laboratory level with the object of making sources of carbon readily available for denitrification. In the course of the experiment, inhibition of fatty acid production by calcareous primary sludge could not be detected. The characteristics of the sludge, such as draining and thickening were considerably improved by the adding of lime.


1992 ◽  
Vol 25 (4-5) ◽  
pp. 59-66 ◽  
Author(s):  
C. Andersson ◽  
M. Tendaj ◽  
M. Rothman

The requirements for purification of the sewage will be more stringent in Sweden. For the three plants in Stockholm - Henriksdal, Bromma and Loudden the proposed limit concentrations for BOD7, total phosphorus and total nitrogen are 10, 0.3 and 15 respectively. A limit value of 0.3 mg/l of phosphorus in the effluent will require a filtration stage. In this paper results are presented from filter tests at Bromma sewage treatment plant. The tests were carried out during almost two years and included operation of different types of sand dual-media downflow filters and an upflow filter. The filters were tested with respect to sludge accumulation capacity, suspended solids removal and phosphorus removal at different operation conditions including chemical precipitation in the filters.


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.


2001 ◽  
Vol 43 (11) ◽  
pp. 109-117 ◽  
Author(s):  
D. Bixio ◽  
P. van Hauwermeiren ◽  
C. Thoeye ◽  
P. Ockier

The municipal sewage treatment plant (STP) of the city of Ghent (Belgium) has to be retrofitted to a 43%-increase in the nitrogen treatment capacity and to phosphorus removal. Cold weather, dilute sewage and a critical COD over N ratio make the retrofit a challenge for full biological nutrient removal. The potential for fermentation of primary sludge to alter those critical feed sewage characteristics was experimentally evaluated. The idea was that the pinpoint introduction of fermentate could optimise the available reactors by achieving high-rate denitrification and enhanced biological phosphorus removal. The fermentation process was evaluated with a bench scale apparatus. At 20°C (heated process), the hydrolysis yield - expressed in terms of soluble COD - varied from 11% to 24% of the total sludge COD. The fermentation yield expressed in VFA COD varied from 8% to 13% of the total sludge COD. The efficiency of heated fermentation of primary sludge was lower during cold and wet weather, due to the different sewage characteristics, as a result of extended dilution periods and low temperature. The raw sewage, the primary effluent and the fermentate were fractionated according to the requirements for the IAWQ Activated Sludge Model No. 2d. The results clearly show that fermentation in the sewer played an important role and temperature was the driving parameter for the characteristics of the dissolved COD. Instead, the weather flow conditions were the driving parameter for the characteristics of the suspended COD. The results of the detailed fractionation were used as background for process evaluation. The final scenario choice for the retrofit depends on a cost-efficiency calculation.


1992 ◽  
Vol 25 (4-5) ◽  
pp. 363-374 ◽  
Author(s):  
F. Rogalla ◽  
G. Roudon ◽  
J. Sibony ◽  
F. Blondeau

Stringent effluent quality programs to limit wastewater discharges into receiving waters require extensive upgrading of conventional wastewater treatment plants. Large facilities built some decades ago are now often located in densely urbanised areas where land is unavailable. Since nitrogen and phophorus removal often require additional unit processes, innovative solutions have to be found to upgrade existing plants for nutrient removal. This paper shows large scale examples of compact technology and the additional upgrading flexibility provided. New facilities are implemented in sensitive neighborhoods by creative siting under sports stadiums, parks or buildings. In covered plants, air emission control becomes of primary importance. To reduce visual impacts and facilitate odour control, more and more underground treatment plants are constructed, allowing multiple use of plant surfaces. Several plants are illustrated in inner-city locations, avoiding infrastructure cost to pump sewage to remote sites. Most of the presented plants incorporate spacesaving settling facilities and high rate biological reactors to reduce the ‘footprints' of the installations and thus favour coverage. Parallel plates in primary setllers reduce the surface to about one tenth of conventional systems. Biocarbone aerated filters combine biodegradation with very high removal rates and retention of particles in one reactor, without additional clarification or filtration. Air treatment for large plant is mostly performed by chemical scrubbing, completely eliminating environmental nuisances. Performance results of both air and water treatment technology are given. Examples include recent sewage treatment plants on the French Mediterranean Coast. A physico-chemical treatment plant for 1 Million p.e. has operated since 1987 under a stadium in Marseille. In Monaco, the sewage treatment plant for 100 000 p.e.is located in the city center underneath a building of 3000 m2. Primary lamella settlers are followed by biological treatment on Biocarbone aerated filters and air is chemically deodourised. Similar technology is used in Antibes' 200 000 p.e. plant, integrated underneath a park close to the beach.


2019 ◽  
Vol 14 (1) ◽  
pp. 198-202
Author(s):  
M. Tang ◽  
J. Liu

Abstract Increasing stringency of environmental discharge standards has triggered an industry-wide inclination towards membrane bioreactors over conventional activated sludge processes to ensure fulfilment of environmental discharge criteria. Yet, despite its plentiful advantages, high aeration costs remain as a key deterrent to the widespread adoption of the MBR technology. This backdrop created an impetus for a wastewater treatment company to develop an efficient MBR air scouring protocol that can be realized in existing plants without retrofitting. Known as pulsed cyclic aeration, plant trial applications have demonstrated that fouling control and aeration savings can be improved by >30%, resulting in scouring energy consumptions that can be as low as 0.049 kWh/m3.


2011 ◽  
Vol 63 (4) ◽  
pp. 680-688 ◽  
Author(s):  
R. Walia ◽  
P. Kumar ◽  
I. Mehrotra

In India, recently, upflow anaerobic sludge blanket (UASB) based sewage treatment plants (STPs) have come up in a big way. Sequence adopted: screens- grit chambers- UASB reactors followed by one-day detention ponds (DP). Performance of DPs located at five STPs (27–70 ML/d) was evaluated over a period of one year from July 2004 to July 2005. The installation of these non-algal ponds reduced land requirement, but from treatment point of view it at best offered only removal of solids washed out of the UASB reactor. Total coliform count in the effluent from ponds ranging from 106 to 109 MPN/100 mL is more than the maximum permissible limit of 10,000 MPN/100 mL. A need has, therefore, been felt to evaluate the possibility of aerating the effluent from UASBR. During aeration, ORP and DO increase, whereas COD and BOD decrease. In a continuous aeration ~50% reduction in COD and nearly 50% increase in DO saturation (DO/DOs) can be achieved by increasing ORP from −100 to 122 mV. Regression equation established between ORP and COD/CODi & DO/DOs may find wide application.


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