scholarly journals An autonomous operational trajectory searching system for an economic and environmental membrane bioreactor plant using deep reinforcement learning

2020 ◽  
Vol 81 (8) ◽  
pp. 1578-1587 ◽  
Author(s):  
KiJeon Nam ◽  
SungKu Heo ◽  
Jorge Loy-Benitez ◽  
Pouya Ifaei ◽  
ChangKyoo Yoo
Keyword(s):  
Reinforcement Learning ◽  
Membrane Bioreactor ◽  
Optimal Operation ◽  
Treatment Efficiency ◽  
Optimal Operating ◽  
Operational Costs ◽  
Aeration System ◽  
Effluent Discharge ◽  
Aeration Process ◽  
Micro Organisms

Abstract Optimal operation of membrane bioreactor (MBR) plants is crucial to save operational costs while satisfying legal effluent discharge requirements. The aeration process of MBR plants tends to use excessive energy for supplying air to micro-organisms. In the present study, a novel optimal aeration system is proposed for dynamic and robust optimization. Accordingly, a deep reinforcement learning (DRL)-based optimal operating system is proposed, so as to meet stringent discharge qualities while maximizing the system's energy efficiency. Additionally, it is compared with the manual system and conventional reinforcement learning (RL)-based systems. A deep Q-network (DQN) algorithm automatically learns how to operate the plant efficiently by finding an optimal trajectory to reduce the aeration energy without degrading the treated water quality. A full-scale MBR plant with the DQN-based autonomous aeration system can decrease the MBR's aeration energy consumption by 34% compared to other aeration systems while maintaining the treatment efficiency within effluent discharge limits.

scholarly journals RESEARCH ON IMPROVEMENT OF THE METHOD OF PERIODIC AERATION OF WASTEWATER

2021 ◽  
pp. 90-95
Author(s):  
Mykola Mits ◽  
Kostyantin Beloshenko ◽  
Anatoly Bozhkov
Keyword(s):  
Wastewater Treatment ◽  
Control Method ◽  
Optimal Operation ◽  
Aeration Tank ◽  
Oxygen Balance ◽  
Treatment Technology ◽  
Aeration System ◽  
Entire Complex ◽  
Treatment Facilities ◽  
Aeration Process

The aeration process is a key part of biological wastewater treatment technology. But, paradoxically, during the existence of this technology, it has not changed significantly. The process of aeration of wastewater remains the largest consumer of electricity in the entire complex of treatment facilities. The possibility of adjusting the duration of the aeration cycle depending on the "explosive" change in the amount of contaminants was stated. In this case, the system must respond to this "perturbation" and adjust the duration of the aeration cycle to provide the necessary oxygen regime of biological oxidation of contaminants. The research data on the method of periodic aeration based on a comparison of the concentration of oxygen in the liquid to be cleaned and in the gases leaving after aeration are presented. The basic principle is that the aeration system continues to supply oxygen, which is no longer able to diffuse into the aerated liquid, and comes to the surface, bypassing the process of mass transfer. The experimentally established method of adjusting the duration of aeration periods for implementation in one aeration tank can be applied to a whole group of aeration tanks. Using the method in the optimal mode for each of the specified number of aeration tanks is impossible without the use of a microprocessor. Therefore, a control method was developed that allows the application of a fundamentally new algorithm for periodic aeration. This algorithm allows to increase the growth of activated sludge and to increase the efficiency of wastewater treatment. To assess the possibility of stabilizing the operation of certain aeration tanks, in the implementation of intermittent aeration by the concentration of oxygen in the liquid, a model example was considered, from which follows the differential equation of oxygen balance in the liquid. The study of this equation for stability and behavior in the phase plane makes it possible to choose the conditions under which the periodic aeration algorithm will be the most efficient in terms of purification and energy consumption. Theoretical calculation gave a mathematical justification for the experimental data. Based on numerical calculations, the condition of optimal operation of the aeration system for a group of aeration tanks is derived. Thus, it was found that the optimal concentration of oxygen in the liquid at which to start aeration is 0.06-0.12 mg / dm3. Periodic aeration with a period of 30 minutes makes it possible to maintain a stable gradient of oxygen concentrations in the liquid. The productivity of treatment plants according to the developed algorithm of controlled aeration, in accordance with the concentration of oxygen in the liquid to be cleaned, ensures the rational use of electricity.

Photo-degradation of butyl parahydroxybenzoate by using TiO2-supported catalyst

2013 ◽  
Vol 67 (10) ◽  
pp. 2141-2147 ◽  
Author(s):  
Patrick Atheba ◽  
Patrick Drogui ◽  
Brahima Seyhi ◽  
Didier Robert
Keyword(s):  
Flow Rate ◽  
Photocatalytic Oxidation ◽  
Supported Catalyst ◽  
Operating Conditions ◽  
Treatment Efficiency ◽  
Optimal Operating ◽  
Photo Degradation ◽  
Photochemical Process ◽  
Recirculation Flow ◽  
High Treatment

The present work evaluates the potential of the photocatalysis (PC) process for the degradation of butylparaben (BPB). Relatively high treatment efficiency was achieved by comparison to photochemical process. Prior to photocatalytic degradation, adsorption (AD) of BPB occurred on the titanium dioxide (TiO2)-supported catalyst. AD was described by Langmuir isotherm (KL = 0.085 L g−1, qm = 4.77 mg g−1). The influence of angle of inclination of the reactor, pH, recirculation flow rate and initial concentration of BPB were investigated. The PC process applied under optimal operating conditions (recirculation flow rate of 0.15 L min−1, angle of inclination of 15°, pH = 7 and 5 mg L−1 of BPB) is able to oxidize 84.9–96.6% of BPB and to ensure around 38.7% of mineralization. The Langmuir–Hinshelwood kinetic model described well the photocatalytic oxidation of BPB (k = 7.02 mg L−1 h−1, K = 0.364 L mg−1).

Optimal Operation and Maintenance of Gas Compressor Stations: An Integrated Framework Applied to a Large-Scale Industrial Case

2015 ◽  
Vol 138 (4) ◽  
Author(s):  
Dionysios P. Xenos ◽  
Erling Lunde ◽  
Nina F. Thornhill
Keyword(s):  
Optimization Model ◽  
Large Scale ◽  
Optimal Schedule ◽  
Optimal Operation ◽  
Optimal Distribution ◽  
Compressor Station ◽  
Operational Costs ◽  
Operation And Maintenance ◽  
Maintenance Model ◽  
Operational Aspects

This paper presents a framework which integrates maintenance and optimal operation of multiple compressors. The outcome of this framework is a multiperiod plan which provides the schedule of the operation of compressors: the schedule gives the best decisions to be taken, for example, when to carry out maintenance, which compressors to use online and how much to load them. These decisions result in the minimization of the total operational costs of the compressors while at the same time the demand of the plant is met. The suggested framework is applied to an industrial gas compressor station which encompasses large multistage centrifugal compressors operating in parallel. The optimization model of the framework consists of three main parts: the models of compressor maps, the operational aspects of compressors, and a maintenance model. The results illustrate the optimal schedule for 90 days and an example of the optimal distribution of the load of the compressors for 5 days. Finally, the results show the economical benefits from the integration of maintenance and optimization.

scholarly journals Comparative study of submerged membrane bioreactor and extended aeration process coupled with tubesettler for hospital wastewater treatment

2020 ◽  
Vol 59 (6) ◽  
pp. 4633-4641
Author(s):  
Rachida El Morabet ◽  
Roohul Abad Khan ◽  
Javed Mallick ◽  
Nadeem A. Khan ◽  
Sirajuddin Ahmed ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Comparative Study ◽  
Membrane Bioreactor ◽  
Hospital Wastewater ◽  
Submerged Membrane Bioreactor ◽  
Aeration Process

A comparison of a blower and a Venturi aeration system in a submerged membrane bioreactor

2017 ◽  
Vol 69 ◽  
pp. 109-115
Author(s):  
Necati Kayaalp ◽  
Gokmen Ozturkmen ◽  
Ertugrul Gul ◽  
Elif Gunay
Keyword(s):  
Membrane Bioreactor ◽  
Submerged Membrane Bioreactor ◽  
Aeration System

scholarly journals The Search of Optimal Operating Regimes by Studying Velocity Fields in an Air Model of a Microhydroturbine

2020 ◽  
Vol 15 (2) ◽  
pp. 73-83
Author(s):  
Daniil A. Suslov ◽  
Ivan V. Litvinov ◽  
Yevgeny Yu. Gorelikov ◽  
Sergey I. Shtork
Keyword(s):  
Water Resource ◽  
Hydraulic Turbine ◽  
Optimal Operation ◽  
Velocity Fields ◽  
Optimal Regime ◽  
Optimal Operating ◽  
The Given ◽  
Operating Regimes ◽  
Air Medium ◽  
Swirl Parameter

This article is devoted to the search for conditions for optimal operation of a microhydroturbine model. The experiments were carried out in air medium. Velocity fields were measured in the outlet cone of a hydraulic turbine using an LDA system. It was shown that by modeling the flow in the air, using the integral swirl parameter S, it is possible to quickly determine the optimal regime of operation of the turbine for the given parameters of the water resource.

scholarly journals Comparative Study between Membrane Bioreactor MBR and Rotating Biological Contactors RBC for Greywater Treatment

2021 ◽  
Vol 12 (4) ◽  
pp. 107-111
Author(s):  
Amr M. Abdelkader ◽  
Keyword(s):  
Pilot Plant ◽  
Biological Treatment ◽  
Membrane Bioreactor ◽  
Settling Tank ◽  
Suspended Solid ◽  
Treatment Efficiency ◽  
Proposed Model ◽  
Nitrification Process ◽  
Rotating Biological Contactors ◽  
Work Done

Greywater is the major part of water consumption in houses. Greywater should be treated to complying with the specifications for several purposes such as toilet flush, landscaping irrigation, and agriculture. The treatment efficiency of both MBR and RBC systems was investigated by using a verified mathematical model. The simulation program GPS-X (version 6.0) was used to simulate both MBR and RBC systems. The simulation model for biological treatment for both MBR and RBC systems is based on Activated Sludge Model 1 (ASM1). The experimental data for model calibration and verification for the MBR system were taken from experimental work done at Tubitak, Marmara Research Center, Turkey ATASOY. As well as the RBC proposed model was verified also by using RBC experimental results for a pilot plant according to BABAN. The RBC pilot plant consists of three units, The first is the RBC unit, the second unit is the settling tank and the last unit is the disinfection tank. The results of the MBR plant showed that the removal efficiencies of the greywater were: 95% for COD; 95% for BOD5; 96% for TKN; 92% for NH4+ and 99% for TSS. Whereas, the results of the RBC show that, The BOD efficiency removal was ranged between about 93.0 to 96.0 %, and for the total SS removal was ranged between 84.0 to 95.0 %. The MBR system provides complete nitrification and suspended solid removal. The RBC system provides less nitrification process and suspended solid removal. The effluent of the rotating biological contactors units for the greywater could be reused after filtration and disinfection with minimal cost of operation. The effluent of the membrane bioreactor unit needs only disinfection before reuse.

Two approaches to indirect potable reuse using membrane technology

2000 ◽  
Vol 41 (10-11) ◽  
pp. 149-156 ◽  
Author(s):  
J. Lozier
Keyword(s):  
Membrane Bioreactor ◽  
Wastewater Effluent ◽  
Secondary Effluent ◽  
Potable Reuse ◽  
Wwtp Effluent ◽  
Indirect Potable Reuse ◽  
Effluent Discharge ◽  
The City ◽  
Raw Wastewater ◽  
Bioreactor Process

A pilot study was conducted at McAllen, Texas to evaluate two microfiltration technologies, Memcor and ZeeWeed, to treat secondary effluent from the city of McAllen south WWTP. The objectives of the study were to compare the ability of Memcor and ZeeWeed to pretreat secondary effluent for subsequent processing by RO and to evaluate the ability of the ZenoGem membrane bioreactor process to directly treat screened, de-gritted wastewater to a quality suitable for direct processing by RO. The results showed both Memcor and ZeeWeed to be competitive in their ability to produce a high quality filtrate from secondary effluent. The results also indicated that the ZenoGem process is capable of producing a filtrate suitable for RO treatment while meeting the City's current wastewater effluent discharge requirements. Additionally, the ZenoGem treated McAllen's raw wastewater to a quality comparable to the city's existing WWTP effluent.

The Reactor Size Influence on the Optimal Operating Setpoint Choice for a Fixed-Bed Multi-Tubular Catalytic Reactor

2018 ◽  
Vol 69 (8) ◽  
pp. 2012-2018
Author(s):  
Constantin Muscalu ◽  
Gheorghe Maria ◽  
Daniel Dinculescu
Keyword(s):  
Design Variable ◽  
Thermal Sensitivity ◽  
Fixed Bed ◽  
Heat Removal ◽  
Optimal Operation ◽  
Pareto Optimal ◽  
Optimal Operating ◽  
Control Variables ◽  
Reaction Heat ◽  
Pareto Optimal Front

Optimal operation of chemical reactors of high thermal sensitivity is a central engineering problem of very high current interest. One elegant alternative to choose the optimal setpoint when at least two contrary (opposite) objectives are considered is based on the so-called Pareto-optimal front technique. This paper exemplifies how to generate Pareto optimal operating policies when reactor productivity and safety objectives (expressed in probabilistic terms) are simultaneously considered in the presence of technological constraints, uncertainty in safety boundaries, and random fluctuations in control variables. Beside the operating control variables, one important design variable is the reactor pipe diameter because it is directly related to the reaction heat removal. This paper exemplifies the influence of this design variable on the setpoint choice when applying the Pareto-optimal front method with computing the runaway-boundaries by using the generalized sensitivity criterion of Morbidelli and Varma (MV-criterion). An example is provided for an industrial fixed-bed tubular reactor used for the catalytic oxidation of benzene to maleic anhydride (MA) in vapour phase.

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