Robust water quality controller for a reverse osmosis desalination system

2015 ◽  
Vol 16 (2) ◽  
pp. 324-332 ◽  
Author(s):  
Bui Duc Hong Phuc ◽  
Sam-Sang You ◽  
Tae-Woo Lim ◽  
Hwan-Seong Kim
Keyword(s):  
Water Quality ◽  
Reverse Osmosis ◽  
Mimo System ◽  
External Disturbance ◽  
Water Desalination ◽  
Water Quality Control ◽  
Product Water ◽  
Plant Uncertainty ◽  
Control Methodology ◽  
Quality Controller

This paper presents two-degree-of-freedom (2-DOF) robust loop-shaping control methodology to stabilize a reverse osmosis (RO) desalination system operating under significant uncertainties, external disturbances and measurement noises, and to reduce product water cost. This method has the advantages that no information about the plant uncertainty is required and it can deal with external disturbance and noise simultaneously. The controlled RO plant is a multi-input multi-output (MIMO) system. The two controlled variables are product water flow and product water salinity, which are fundamental in water desalination. The result shows that the achieved controller has very good performance which can deal with up to 52% uncertainty, and eliminate 60% of disturbance and 70% of noise, while common existing controllers in RO desalination can't cover the uncertainty and disturbance or can only deal with small values of these factors. Now that the software and hardware in the RO plant are sufficiently robust, it is possible to use this powerful method for better water quality control of RO systems.

scholarly journals Experimental versus theoretical study of reverse osmosis pilot scaling: The case of Algerian brackish water desalination

2019 ◽  
Vol 42 (1) ◽  
pp. 49-58
Author(s):  
Abderrezak Bouchareb ◽  
Mehdi Metaiche ◽  
Hakim Lounici
Keyword(s):  
Water Quality ◽  
Ground Water ◽  
Reverse Osmosis ◽  
Brackish Water ◽  
System Analysis ◽  
Sea Water ◽  
Rejection Rate ◽  
Water Shortage ◽  
Water Desalination ◽  
Ground Water Quality

Abstract In recent years, the increasing threat to ground water quality due to human activities has become a matter of great concern. The ground water quality problems present today are caused by contamination and by over exploitation or by combination of both. Reverse osmosis (RO) desalination is one of the main technologies for producing fresh water from sea water and brackish ground water. Algeria is one of the countries which suffer from the water shortage since many years, so desalination technology becomes inevitable solution to this matter. In this study, a comparison is provided of results of reverse osmosis desalination for three different qualities of brackish water from the central-east region of Algeria (Bouira and Setif Prefectures), wherein they cannot use it as human drinking or in irrigation systems. The main objective of our study is to establish a comparison of the reverse osmosis membrane TW30-2540 performances in the term of (permeate flow, recovery rate, permeate total dissolved solids – TDS and salts rejection) under different operation pressures (each one takes a time of 720 second for pilot scaling). In order to make an overview comparison between the experimental and the simulated results we used ROSA (Reverse Osmosis System Analysis) software. At the end of this study we noted that, the simulated results are lower than the pilot scaling values and the most removed salts are the sodium chlorides with 99.05% of rejection rate.

The Study on the Effect on Seawater Desalination and Boron Removal by Ro-EDI Desalination System

2014 ◽  
Vol 955-959 ◽  
pp. 3211-3215
Author(s):  
Zhao Ji Hu ◽  
Yi Liang Hu ◽  
Er Ming Ouyang ◽  
Fei Feng
Keyword(s):  
Water Quality ◽  
Reverse Osmosis ◽  
Boron Concentration ◽  
Total Dissolved Solids ◽  
Feed Water ◽  
Boron Removal ◽  
Experimental Parameters ◽  
Product Water ◽  
Simulated Seawater ◽  
Process Coupling

A hybrid process coupling reverse osmosis (RO) with electrodeionization (EDI) was investigated to remove TDS and boron from simulated seawater in this study. The effects of applied total dissolved solids (TDS) and the concentration of boron in the feed water on product water quality were investigated. According to the results obtained, the TDS of the product water increased when a high applied TDS in the feed water; however, all of the TDS of the product were complying with relevant standards within experimental parameters. When the boron concentration was below 5.64mg/L in the feed water, the boron concentration of the product water was complying with relevant standards.

scholarly journals Economics and Energy Consumption of Brackish Water Reverse Osmosis Desalination: Innovations and Impacts of Feedwater Quality

Membranes ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 616
Author(s):  
Jeffrey L. Pearson ◽  
Peter R. Michael ◽  
Noreddine Ghaffour ◽  
Thomas M. Missimer
Keyword(s):  
Water Quality ◽  
Reverse Osmosis ◽  
Brackish Water ◽  
Energy Use ◽  
Operating Cost ◽  
Electrical Energy ◽  
The United States ◽  
Water Desalination ◽  
Feed Water ◽  
Plant Capacity

Brackish water desalination, using the reverse osmosis (BWRO) process, has become common in global regions, where vast reserves of brackish groundwater are found (e.g., the United States, North Africa). A literature survey and detailed analyses of several BWRO facilities in Florida have revealed some interesting and valuable information on the costs and energy use. Depending on the capacity, water quality, and additional scope items, the capital cost (CAPEX) ranges from USD 500 to USD 2947/m3 of the capacity (USD 690–USD 4067/m3 corrected for inflation to 2020). The highest number was associated with the City of Cape Coral North Plant, Florida, which had an expanded project scope. The general range of the operating cost (OPEX) is USD 0.39 to USD 0.66/m3 (cannot be corrected for inflation), for a range of capacities from 10,000 to 70,000 m3/d. The feed-water quality, in the range of 2000 to 6000 mg/L of the total dissolved solids, does not significantly impact the OPEX. There is a significant scaling trend, with OPEX cost reducing as plant capacity increases, but there is considerable scatter based on the pre- and post-treatment complexity. Many BWRO facilities operate with long-term increases in the salinity of the feedwater (groundwater), caused by pumping-induced vertical and horizontal migration of the higher salinity water. Any cost and energy increase that is caused by the higher feed water salinity, can be significantly mitigated by using energy recovery, which is not commonly used in BWRO operations. OPEX in BWRO systems is likely to remain relatively constant, based on the limitation on the plant capacity, caused by the brackish water availability at a given site. Seawater reverse osmosis facilities, with a very large capacity, have a lower OPEX compared to the upper range of BWRO, because of capacity scaling, special electrical energy deals, and process design certainty.

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