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A Conceptual Model for ZLD of Brackish Water RO DesalinationDr. MAMDOUH AYAD GADALLAAbstract: This work proposes a novel process flowsheet for ZLD for brackish water RO desalination. A conceptual model based on mass/energy balances to simulate this process flowsheet is presented using EXCEL to modify an existing RO facility to reach a zero-liquid-discharge scheme. The novel flowsheet comprises an RO followed by an electrolyzer, concrete thermal storage, solar evaporator, and mixing tank. The water reject from the RO is split into three fractions, one to an electrolyzer to produce H2, another to solar evaporator to produce freshwater, third is remixed with water from the evaporator to reduce the salinity of the RO feed. The hydrogen produced in the electrolyzer is burned and its energy is stored using cement blocks. The theoretical model is tested for desalination of brackish water with 8000 ppm TDS. For a small capacity of 2000 l/d, the following results were obtained for 400 ppm freshwater: Water from well = 785 l Produced H2 = 4.33 kg/d Cement required = 984.6 kg for 14 h Solar energy = 3.81 kW for 10 h pZLD = 5.8% The cost of modifications to the conventional desalination unit is 511,900 EGP (capital) and 189 EGP/h (operating), resulting in 94.5 EGP/h profit with 9 months-payback times. |
Dr. MAMDOUH AYAD GADALLA
Dr. Gadalla graduated with a B.Sc. (Hons) and an M.Sc. in Chemical Engineering from Cairo University. He completed his Ph.D. from the University of Manchester (UMIST) in Process Integration. Dr. Gadalla worked as a Post-Doctoral Researcher at Delft University of Technology (Holland). From 2005 till 2010, Dr. Gadalla joined Universitat Rovira I Virgili URV in Spain as an Assistant Professor. Early 2011, Dr. Gadalla Joined the British University in Egypt as an Associate Professor in Chemical Engineering Dept. Currently, Dr. Gadalla is a Professor and Head of the Chemical Engineering Dept. at Port Said University, and an Adjunct Professor at BUE. Dr. Gadalla received the Egyptian Incentive-Award (جائزه الدولة التشجیعیة) for Engineering Research (2015) and the Medal of Excellence (نوط الامتیاز-الطبقه الاولی) from the President of Egypt (2017).
