Decentralized Adaptive PI with Adaptive Interaction Algorithm of Wastewater Treatment Plant

2014 ◽  
Vol 67 (5) ◽  
Author(s):  
M. F. Rahmat ◽  
S. I. Samsudin ◽  
N. A. Wahab ◽  
Mashitah Che Razali ◽  
Muhammad Sani Gaya

Wastewater treatment plant (WWTP) is highly known with the variation and uncertainty of the parameters, making them a challenge to be tuned and controlled. In this paper, an adaptive decentralized PI controller is developed for nonlinear activated sludge WWTP. The work is highlighted in auto-tuning the PI control parameters in satisfying straighten effluent quality and hence optimizing the nitrogen removal. The PI controller parameters are obtained by using simple updating algorithm developed based on adaptive interaction theory. The error function is minimized directly by approximate Frechet tuning algorithm without explicit estimation of the model. The effectiveness of the proposed controller is then validated by comparing the performance of activated sludge process to the benchmark PI under three different weather conditions with realistic variations in influent flow rate and composition. The algorithm is effectively applied in activated sludge system with improved dynamic performances in effluent quality index and energy consumed of Benchmark Simulation Model No.1.

1998 ◽  
Vol 37 (12) ◽  
pp. 141-148 ◽  
Author(s):  
B. K. Lee ◽  
S. W. Sung ◽  
H. D. Chun ◽  
J. K. Koo

The objective of this study is to develop an automatic control system for dissolved oxygen (DO) and pH of the activated sludge process in a coke wastewater treatment plant. A discrete type autotuned proportional-integral (PI) controller using an auto-regressive exogenous (ARX) model as a process model was developed to maintain the DO concentration in aerators by controlling the speed of surface aerators. Also a nonlinear pH controller using the titration curve was used to control the pH of influent wastewater. This control system was tested in a pilot scale plant. During this pilot plant experiment, there was small deviation of pH and the electric power consumption of surface aerators was reduced up to 70% with respect to the full operation when the DO set point was 2 mg/l. For real plant operation with this system, the discrete PI controller showed good tracking for set point change. The electricity saving was more than 40% of the electricity consumption when considering surface aerators. As a result of maintaining the DO constantly at the set point by the automatic control system, the fluctuation of effluent quality was decreased and overall improvement of the effluent water quality was achieved.


1996 ◽  
Vol 33 (12) ◽  
pp. 255-258 ◽  
Author(s):  
Olga Burica ◽  
Marjeta Strazar ◽  
Ivan Mahne

The recirculation activated sludge process with preanoxic treatment was applied for biological reduction of the nitrogen content in municipal wastewater at pilot plant level. The pilot plant of total volume 3 300 1 with an initial anoxic to aerobic volume ratio of 40 : 60 was fed with wastewater from the first heavily loaded aerobic stage of a local wastewater treatment plant. Experiments were run over the summer and winter periods, the influent wastewater temperature being approx 24°C and approx 10°C, respectively. Special attention was paid to the hydraulic retention time, the total as well as mineral nitrogen loading, the aerobic to anaerobic volume ratio, and to the energy demand for denitrification of oxidised mineral nitrogen forms. Under optimal operating conditions the effluent quality that could be achieved was about 10 mg/l of total nitrogen (74% removal) and less than 2 mg N/l mineral nitrogen (87% removal), while simultaneously 205 mg BOD5/l in the influent was reduced to less than 7mg O2/l in the effluent. It was found feasible from the pilot plant experiments to upgrade an existing two stage aerobic-anaerobic wastewater treatment plant to reduce nitrogen from the liquid fraction of municipal wastewater so as to meet effluent quality standards without much additional volume and without amending the energy source for bioconversion of oxidised mineral nitrogen to gaseous forms.


1999 ◽  
Vol 39 (2) ◽  
pp. 145-150
Author(s):  
T. Dormoy ◽  
B. Tisserand ◽  
L. Herremans

The new regulations require an increased amount of treatment of stormwater and a reduction of pollution loads discharged into the natural surroundings to be considered. Drainage systems therefore and particularly wastewater treatment plants should be sized correctly to cope with these peaks. Using a simulation software of wastewater treatment plant with activated sludge, such as SIMBAD, enables us to check that planned structures are appropriate in relation to the effluent quality requirements laid down, and to fix the most appropriate operating procedures. Operating constraints on a plant for treating stormwater are not negligible. It is advisable to allow for increased sludge production, O2 requirements and also sludge quality (fermentability).


1990 ◽  
Vol 22 (7-8) ◽  
pp. 131-138
Author(s):  
Ahmed Fadel

Many of Egypt's cities have existing treatment plants under operation that have been constructed before 1970. Almost all of these treatment plants now need rehabilitation and upgrading to extend their services for a longer period. One of these plants is the Beni Suef City Wastewater Treatment Plant. The Beni Suef WWTP was constructed in 1956. It has primary treatment followed by secondary treatment employing intermediate rate trickling filters. The BOD, COD, and SS concentration levels are relatively high. They are approximately 800, 1100, and 600 mg/litre, respectively. The Beni Suef city required the determination of the level of work needed for the rehabilitation and upgrading of the existing 200 l/s plant and to extend its capacity to 440 l/s at year 2000 A description of the existing units, their deficiencies and operation problems, and the required rehabilitation are presented and discussed in this paper. Major problems facing the upgrading were the lack of space for expansion and the shortage of funds. It was, therefore, necessary to study several alternative solutions and methods of treatment. The choice of alternatives was from one of the following schemes: a) changing the filter medium, its mode of operation and increasing the number of units, b) changing the trickling filter to high rate and combining it with the activated sludge process, for operation by one of several possible combinations such as: trickling filter-solids contact, roughing filter-activated sludge, and trickling filter-activated sludge process, c) dividing the flow into two parts, the first part to be treated using the existing system and the second part to be treated by activated sludge process, and d) expanding the existing system by increasing the numbers of the different process units. The selection of the alternative was based on technical, operational and economic evaluations. The different alternatives were compared on the basis of system costs, shock load handling, treatment plant operation and predicted effluent quality. The flow schemes for the alternatives are presented. The methodology of selecting the best alternative is discussed. From the study it was concluded that the first alternative is the most reliable from the point of view of costs, handling shock load, and operation.


1992 ◽  
Vol 25 (4-5) ◽  
pp. 203-209 ◽  
Author(s):  
R. Kayser ◽  
G. Stobbe ◽  
M. Werner

At Wolfsburg for a load of 100,000 p.e., the step-feed activated sludge process for nitrogen removal is successfully in operation. Due to the high denitrification potential (BOD:TKN = 5:1) the effluent total nitrogen content can be kept below 10 mg l−1 N; furthermore by some enhanced biological phosphate removal about 80% phosphorus may be removed without any chemicals.


1997 ◽  
Vol 36 (2-3) ◽  
pp. 1-8 ◽  
Author(s):  
P. Grau ◽  
B. P. Da-Rin

An unusually severe case of toxicity accompanied by activated sludge filamentous bulking was observed at the wastewater treatment plant Sao Paulo-Barueri. Treatment efficiency of the plant, operated without major problems for more than five years before, was significantly hindered for almost six months. Occurrence of toxic shocks was confirmed partly directly but mostly indirectly by inhibition of nitrification and biological phenomena related to toxicity. Several measures adopted, including the recycled activated sludge chlorination, are described in the paper.


Author(s):  
Maria Clara V. M. Starling ◽  
Elizângela P. Costa ◽  
Felipe A. Souza ◽  
Elayne C. Machado ◽  
Juliana Calábria de Araujo ◽  
...  

AbstractThis work investigated an innovative alternative to improve municipal wastewater treatment plant effluent (MWWTP effluent) quality aiming at the removal of contaminants of emerging concern (caffeine, carbendazim, and losartan potassium), and antibiotic-resistant bacteria (ARB), as well as disinfection (E. coli). Persulfate was used as an alternative oxidant in the solar photo-Fenton process (solar/Fe/S2O82−) due to its greater stability in the presence of matrix components. The efficiency of solar/Fe/S2O82− at neutral pH using intermittent iron additions is unprecedented in the literature. At first, solar/Fe/S2O82− was performed in a solar simulator (30 W m−2) leading to more than 60% removal of CECs, and the intermittent iron addition strategy was proved effective. Then, solar/Fe/S2O82− and solar/Fe/H2O2 were compared in semi-pilot scale in a raceway pond reactor (RPR) and a cost analysis was performed. Solar/Fe/S2O82− showed higher efficiencies of removal of target CECs (55%), E. coli (3 log units), and ARB (3 to 4 log units) within 1.9 kJ L−1 of accumulated irradiation compared to solar/Fe/H2O2 (CECs, 49%; E. coli, 2 log units; ARB, 1 to 3 log units in 2.5 kJ L−1). None of the treatments generated acute toxicity upon Allivibrio fischeri. Lower total cost was obtained using S2O82− (0.6 € m−3) compared to H2O2 (1.2 € m−3). Therefore, the iron intermittent addition aligned to the use of persulfate is suitable for MWWTP effluent quality improvement at neutral pH.


2008 ◽  
Vol 57 (8) ◽  
pp. 1287-1293 ◽  
Author(s):  
A. Jobbágy ◽  
G. M. Tardy ◽  
Gy. Palkó ◽  
A. Benáková ◽  
O. Krhutková ◽  
...  

The purpose of the experiments was to increase the rate of activated sludge denitrification in the combined biological treatment system of the Southpest Wastewater Treatment Plant in order to gain savings in cost and energy and improve process efficiency. Initial profile measurements revealed excess denitrification capacity of the preclarified wastewater. As a consequence, flow of nitrification filter effluent recirculated to the anoxic activated sludge basins was increased from 23,000 m3 d−1 to 42,288 m3 d−1 at an average preclarified influent flow of 64,843 m3 d−1, Both simulation studies and microbiological investigations suggested that activated sludge nitrification, achieved despite the low SRT (2–3 days), was initiated by the backseeding from the nitrification filters and facilitated by the decreased oxygen demand of the influent organics used for denitrification. With the improved activated sludge denitrification, methanol demand could be decreased to about half of the initial value. With the increased efficiency of the activated sludge pre-denitrification, plant effluent COD levels decreased from 40–70 mg l−1 to < 30–45 mg l−1 due to the decreased likelihood of methanol overdosing in the denitrification filter


Sign in / Sign up

Export Citation Format

Share Document