Intelligent control system based on blackboard concept for wastewater treatment processes

1998 ◽  
Vol 37 (12) ◽  
pp. 77-85 ◽  
Author(s):  
T. Ohtsuki ◽  
T. Kawazoe ◽  
T. Masui
Keyword(s):  
Wastewater Treatment ◽  
Control System ◽  
Activated Sludge ◽  
Intelligent Control ◽  
Software Agents ◽  
High Rate ◽  
Target System ◽  
Activated Sludge Process ◽  
Intelligent Control System ◽  
Treatment Processes

An intelligent control system for wastewater treatment processes has been developed and applied to fullscale, high-rate, activated sludge process control. In this control system, multiple software agents that model the target system using their own modeling method collaborate by using data stored in an abstracted database named ‘blackboard’. The software agents, which are called ‘expert modules’, include a fuzzy expert system, a fuzzy controller, a theoretical activated sludge model, and evaluators of raw data acquired by various online sensors including a respirometer. In this paper, the difficulties of controlling an activated sludge system by using a single conventional strategy are briefly reviewed, then our approach to overcome these difficulties by using multiple modeling methods in the framework of an ‘intelligent control system’ is proposed. Case studies of applications to a high-rate activated sludge process that treats BOD and nitrogen of human excrement are also presented.

Rehabilitation and Upgrading of the Beni Suef City Wastewater Treatment Plant

1990 ◽  
Vol 22 (7-8) ◽  
pp. 131-138
Author(s):  
Ahmed Fadel
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Primary Treatment ◽  
High Rate ◽  
Shock Load ◽  
Economic Evaluations ◽  
Activated Sludge Process ◽  
Trickling Filter

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.

Automatic control for DO and pH in the activated sludge process in a coke wastewater treatment plant

1998 ◽  
Vol 37 (12) ◽  
pp. 141-148 ◽  
Author(s):  
B. K. Lee ◽  
S. W. Sung ◽  
H. D. Chun ◽  
J. K. Koo
Keyword(s):  
Wastewater Treatment ◽  
Control System ◽  
Activated Sludge ◽  
Automatic Control ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Pi Controller ◽  
Activated Sludge Process ◽  
Set Point ◽  
Coke Wastewater

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.

Control of Cryptosporidium with wastewater treatment to prevent its proliferation in the water cycle

2003 ◽  
Vol 47 (9) ◽  
pp. 45-49 ◽  
Author(s):  
M. Suwa ◽  
Y. Suzuki
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Municipal Wastewater ◽  
Water Cycle ◽  
River System ◽  
Chemical Precipitation ◽  
Aluminium Chloride ◽  
Activated Sludge Process ◽  
Sand Filter ◽  
Treatment Processes

The outbreak of Cryptosporidiosis in 1996 in Japan is thought to have been enlarged by the proliferation of Cryptosporidium in the water cycle from wastewater to drinking water through the river system. From this experience, the wastewater system must have functions to remove Cryptosporidium oocysts effectively. Efficiencies of wastewater treatment processes to remove oocysts were investigated using pilot plants receiving municipal wastewater. An activated sludge process and a following sand filter showed removal efficiencies of 2 log and 0.5 log, respectively. Poly-aluminium chloride dosage improved the efficiencies by 3 log for the activated sludge process and by 2 log for the sand filter. Chemical precipitation of raw wastewater with poly-aluminium chloride could achieve 1 to 3 log removal according on the coagulant concentration.

scholarly journals Fate of Emerging Contaminants in High-Rate Activated Sludge Systems

2021 ◽  
Vol 18 (2) ◽  
pp. 400
Author(s):  
Elena Koumaki ◽  
Constantinos Noutsopoulos ◽  
Daniel Mamais ◽  
Gerasimos Fragkiskatos ◽  
Andreas Andreadakis
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Emerging Contaminants ◽  
Endocrine Disrupting Chemicals ◽  
High Rate ◽  
Sustainable Technologies ◽  
Treatment Processes ◽  
Secondary Sludge ◽  
Positive Treatment ◽  
Dominant Process

High-rate activated sludge (HRAS) systems are designed to shift the energy-intensive processes to energy-saving and sustainable technologies for wastewater treatment. The high food-to-microorganism (F/M) ratios and low solid retention times (SRTs) and hydraulic retention times (HRTs) applied in HRAS systems result in the maximization of organic matter diversion to the sludge which can produce large amounts of biogas during anaerobic digestion, thus moving toward energy-neutral (or positive) treatment processes. However, in addition to the energy optimization, the removal of emerging contaminants (ECs) is the new challenge in wastewater treatment. In the context of this study, the removal efficiencies and the fates of selected ECs (three endocrine disruptors (endocrine disrupting chemicals (EDCs))—nonylphenol, bisphenol A and triclosan, and four pharmaceuticals (PhACs)—ibuprofen, naproxen, diclofenac and ketoprofen) in HRAS systems have been studied. According to the results, EDCs occurred in raw wastewater and secondary sludge at higher concentrations compared to PhACs. In HRAS operating schemes, all compounds were poorly (<40%) to moderately (<60%) removed. Regarding removal mechanisms, biotransformation was found to be the dominant process for PhACs, while for EDCs sorption onto sludge is the most significant removal mechanism affecting their fates and their presence in excess sludge.

Design of the Intelligent Control System Integration of Wastewater Treatment

2014 ◽  
Vol 716-717 ◽  
pp. 1591-1594
Author(s):  
Wen Hua Chen ◽  
Qiang Cai ◽  
Xu Wang
Keyword(s):  
Water Quality ◽  
Wastewater Treatment ◽  
Control System ◽  
Intelligent Control ◽  
High Efficiency ◽  
Control Method ◽  
Reference Value ◽  
Quality Parameters ◽  
Water Quality Parameters ◽  
Intelligent Control System

In order to achieve the integrated process of wastewater treatment, this research designs a kind of intelligent control system that can monitoring water quality parameters in real-time, which is small, convenient control, high efficiency and low consumption. The acquisition station and control station of the system are based on STM32F107 and industrial control tablet, combined with IASBR process to achieve simultaneous removal of organic matter, nitrogen, phosphorus and COD in wastewater. This system can monitor water temperature, pH, ORP, DO and other water quality parameters. Aiming at the uncertainty of the DO in process control, the fuzzy control method is proposed to realize the rationalization of aeration, meet the needs of wastewater biochemical treatment of the DO. It has a certain reference value to the intelligent development of integrated wastewater treatment.

Step-feed operation at short detention times – a cost effective method for improving wastewater treatment

2000 ◽  
Vol 41 (9) ◽  
pp. 15-20 ◽  
Author(s):  
R.E. Adamski ◽  
V. DeSantis ◽  
A. Spangel ◽  
J. Pynn ◽  
L. Betty ◽  
...  
Keyword(s):  
New York ◽  
Wastewater Treatment ◽  
Activated Sludge ◽  
Nitrogen Removal ◽  
Control Plant ◽  
Treatment Plant ◽  
Cost Savings ◽  
High Rate ◽  
Secondary Treatment ◽  
Activated Sludge Process

The Newtown Creek Water Pollution Control Plant (WPCP) is New York City's largest wastewater treatment plant. Wastewater treatment is provided by a high-rate activated sludge process without primary sedimentation. This process has achieved approximately 65 percent BOD5 and 75 percent TSS removal. As part of a revised facility plan, two alternative tracks were recommended for upgrading the plant to secondary treatment and providing nitrogen removal. One track would require demolishing most of the existing tankage and constructing new primary tanks followed by a step-feed biological nitrogen removal activated sludge process. The second track would preserve the existing high-rate activated sludge process and use biological filters to remove additional TSS, BOD5 and nitrogen. Alternatives have been investigated to enhance treatment at the Newtown Creek WPCP while the secondary treatment plant upgrading is being completed. This investigation demonstrated that simply converting the existing aeration tanks to step-feed operation could significantly improve TSS and BOD removals. These findings have led the City to consider a third track to meet secondary treatment requirements, (but with no nitrogen removal), consisting of modifying the existing plant to step-feed and adding additional step-feed aeration/sedimentation capacity. This track offers significant cost savings over Track 1 and Track 2.

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