Contents lists available at ScienceDirect Journal of Water Process Engineering journal homepage: www.elsevier.com/locate/jwpe Nanofiltration process combined with electrochemical disinfection for drinking water production: Feasibility study and optimization Soufian El-Ghzizel*, Hajar Zeggar, Mustapha Tahaikt, Fathallah Tiyal, Azzedine Elmidaoui, Mohamed Taky Laboratory of Separation Processes, Department of Chemistry, Faculty of Sciences, Ibn Tofail University, Kenitra, 14000, Morocco ARTICLE INFO Keywords: Electrochemical disinfection Electrolysis Nanofiltration Desalination plant ABSTRACT In 2014, the first nitrate removal plant, using nanofiltration (NF) coupled to an electrochemical disinfection system, supplied with renewable energies (Photovoltaic and wind energies) was realized at Al Annouar high school of Sidi Taibi (Kenitra, Morocco). This project was designed to supply the 1200 students of the school with potable water, based on the production capacity of 500 L/h (3 L/Day/student). The local underground water, which is slightly brackish and nitrated, was treated by nanofiltration, using a hybrid renewable energy system, photovoltaic and wind; just before the distribution, an electrochemical disinfection setup was used to disinfect the nanofiltered water. In the first part of this work, the feasibility of the processes combination (nanofiltration- electrochemical water disinfection step) is verified by assessing the main factors which have determined the electrolysis per- formance (Volumetric flow rate, temperature, chloride concentration, energy…). This part of the study is carried out during two years of operation (from April 2014 to February 2016). The second part focused mainly on the optimization of a new membrane treatment plant. The purpose of this installation is twofold; firstly, the ob- jective was to correct the concentration of chloride ions at the inlet of electrolysis. Secondly, it was meant to avoid the quality deterioration of the produced water (nitrates in particular). The results of this study confirmed the feasibility of the process combination: nanofiltration and electro- chemical water disinfection, especially with the use of renewable energies (Photovoltaic and wind). On other hand, this installation will be more attractive by blending raw water with the nanofiltered water in order to increase the performances of the plant hydraulically, energetically, and to correct the chloride concentration for safe disinfection of water. Hence, the produced water by the new installation (process bypass blending) is totally mineral for human consumption and slightly corrosive for pipes and equipments. 1. Introduction Due to the insufficient management of water resources in urban and rural areas in many regions of the world, millions of people are exposed every day to unsafe levels of microbiological and chemical pollutants in their drinking water [1,2]. Almost 1 billion people lack access to an improved supply of safe drinking water. Diarrhoeal disease alone; at- tributed to unsafe water, sanitation and hygiene; cause 2 million annual deaths, mostly concentrated on children in developing countries [3]. The World Health Organization [3] estimates that 94% of diarrhoeal cases are preventable through modifications to the environment, in- cluding interventions to increase the availability of clean water and to improve sanitation and hygiene. The need to disinfect drinking water has encouraged both scientists and engineers to develop new and cost-effective methods for effective water disinfection. These methods may be divided between chemical and physical processes. In chemical processes, disinfecting substances such as ozone, chlorine, and sodium chloride or chlorine dioxide are added to treat water. A frequent drawback of the chemical processes is unwanted side reactions of the disinfectants with substances present in the water that lead to byproducts, some of which are considered dan- gerous [4]. In physical processes such as UV irradiation, membrane separation and thermal disinfection is associated with high cost and maintenance efforts and does not fulfill the requirements for primary and residual water disinfection [5–7]. In the last few decades, alternative systems to conventional disin- fection methods were developed. The most promising ones are based on the in-situ electrogeneration of disinfection agents [4–6,8]. These https://doi.org/10.1016/j.jwpe.2020.101225 Received 29 November 2019; Received in revised form 26 February 2020; Accepted 27 February 2020 ⁎ Corresponding author. E-mail address: elghzizelsoufian85@gmail.com (S. El-Ghzizel). Journal of Water Process Engineering 36 (2020) 101225 2214-7144/ © 2020 Elsevier Ltd. All rights reserved. T