Improving Process Management in a Water Treatment Plant Using Control Modelling (original) (raw)

Process modelling and simulation of a Simple Water Treatment Plant

Water treatment plants are likely to experience problems such as the water level both in the filter cells and in the tanks tend to fluctuate widely. These create the potential for partial drainage, overflow, and potential initial turbidity breakthrough at the beginning of the filtration cycles. This paper presents a mathematical model for studying the process behavior of a water treatment plant. A state equation was developed as a mathematical model of the process. This mathematical model was used to simulate the effects of varying the parameters of the plant (R, C, and I) representing the restriction of the connecting pipes, the capacity of the tanks and the filteration of the water filter, respectively, on the state variables (height of tank, h, and flowrate, q). The results of the simulation are presented graphically in the study. From the analyses, it was observed that varying any of the values of the parameters of the model has an effect on the water levels in the various tanks and the flow of water through the filter. The analyses of this paper on modeling a water treatment plant is a very simple way of knowing from the beginning the various sizes of pipes, tanks and filter to be used and how these will affect the flow of water in the plant before going into the physical construction of the plant.

Process control and optimization of wastewater treatment plants using simulation softwares: a review

International Journal of Advanced Technology and Engineering Exploration, 2016

Among various technologies available for potable water production, the treatment of wastewater is an established technology in several countries such as the USA, Persian Gulf and European countries [1]. On the basis of working energy principle, desalination processes are classified into two classes namely thermal processes which involves phase change due to addition of heat and also membrane processes that involve pressure energy. Further thermal processes can be classified into multi-effect evaporation (MEE), multi stage flash (MSF) and vapor-compression (VC) processes. Membrane processes can be classified into RO and electrodialysis (ED) processes. Among these different technologies for wastewater treatment, MSF processes has many features such as it is large scale operation and has ability to deliver good quality potable water [2]. Water treatment operation was started during early part of 20th century. Water treatment is a complex process which requires efficient and accurate control system in plant to maintain operation at optimum condition so that it will cause minimum product cost and prevention of scale formation. Control systems are of two types one is conventional strategies and other one is advanced control.

Control Strategies of Wastewater Treatment Plants

The objective of the current study is to investigate various control strategies implemented to wastewater treatment plants. The paper starts with discussion in modeling part of wastewater system and continues with designation of control objectives and control parameters. Subsequently, the implementations of common control structures including feedback, feedforward-feedback, supervisory and hierarchical controls are explained. The study is exclusively emphasized on four control techniques. Model predictive control performs superior control in optimizing nitrogen removal based on predictions of future behavior of wastewater systems. The performances of PID control in dissolve oxygen and nitrate control is improved significantly with multivariable configuration. Similar results achieved by data-driven approach compared to default PI simulation. Finally, artificial neural networks are commonly suggested for modeling and prediction purposes. A study is emphasized on Benchmark Simulation Model No. 1. The paper serve as a reference and for future research improvements in developing new advanced control techniques for wastewater field that aims in achieving stringent effluent quality standards.

pH-Control Problems of Wastewater Treatment Plants

DOAJ (DOAJ: Directory of Open Access Journals), 2018

Experimental investigations have been carried out to investigate the pH-control problems of industrial electroplating wastewater treatment plants. The accurate and sensitive PID control system could treat most problem and disturbances in the normal operation of the water treatment. However, conventional treatment was replaced by proprietary treatment agent called a QUASIL which was found to be more effective for a wide range of pH.

Operation and Ph Control of A Wastewater Treatment Unit Using Labview

LABVIEW is a powerful and versatile graphical programming language that had its roots in operation, automation control and data acquisition of the system. The pH control system of a non-linear wastewater treatment unit, contains heavy metals (Cu, Cr, Cd, Fe, Ni and Zn), had been developed depending on dynamics behavior of the process. The pH value of wastewater is change by addition chemicals (lime or Na 2 S). The semi-batch pH process system dynamically behaved as a first order lag with dead time. The tuning of control parameters was carried by several methods; Internal Model Control (IMC), Minimum (ITAE) criteria and Adaptive mode. Since the process was fast, the Integral of Absolute of Error (IAE) criteria was used to compare between the above tuning methods. Adaptive control was the best and effective to determining the values of proportional gain (Kc), Integral time constant (τ I) and Derivative time constant (τ D).PI mode was found to be the best for control the fast pH process.

Process Simulator for Wastewater Treatment Plant

Dynamic models and process simulators can be very useful in creation of effective control systems for wastewater treatment processes. They also allow seizing procedures of designing of technological processes, helping to estimate and to pick up successfully technological parameters, which influence stability and efficiency of processes. Modern wastewater treatment is a quite complex process, which includes several treatment steps before the water is released to the recipient. The typical process of wastewater treatment includes four stages: mechanical treatment, biological treatment, chemical treatment, and sludge treatment. In this paper the separate models for each wastewater treatment stage are combined to form a complex dynamic model for simulation of wastewater treatment plant. Important data from Kaunas wastewater treatment plant are collected to facilitate the identification of mathematical models parameters.

Dynamic Models and Control Strategies for Wastewater Treatment Plants - An Overview

IFAC Proceedings Volumes, 1977

The application of dynamic models and process control techlliques has considerable potential for improv :Ln g the performance of wasteIVater treatment plants. This paper describes a recently developed dynamic model a nd package of control strategies for a t ypica l, modern mllnlrip.~l wa s tewater t reatment plant. Control strategies for each process are described and integrated into a plant control strategy. Thr0 u gh the dynam;c model and simulated controls, the in t eractions among processes and between the plant and its external environment are examined .

Numerical modeling of processes in water treatment plants as a basis for an optimal design

2014

Centrally supplied water for human consumption is subject to complex physico-chemical and biological treatment processes, from the source to the consumer. The degree of complexity for these processes depend both of the quality of the water source as well of the higher quality requirements imposed by regulations. The investment and operating costs of water treatment systems, as well as energy efficiency are also key factors in the selection of the applied technologies. The design of tehnological processes (related both of the capture and water conveyance as well of the water treatment plants) requires a complex engineering approach including specialities related to hydraulics, physical engineering, chemical engineering, electrical installations and industrial automation. The complexity and the interconnection degree of the involved processes (also the higher costs even in the pilot stage) determines the numerical modelling and simulation of processes as a mandatory stage in the desig...