Sergio G. Salinas Rodriguez – författare

Characterizing bulk organic matter in seawater and bay water by various analytical techniques and linking these measurements with fouling in membrane systems. Furthermore, it aimed for the development of the Modified Fouling Index - ultrafiltration (MFI-UF) at constant flux filtration as an accurate test to measure the particulate fouling potential of a feed water and predict the rate of fouling in reverse osmosis systems.A new semi-portable set-up has been successfully developed to perform MFI-UF tests at constant flux filtration. A significant effect of the filtration flux on the fouling potential was found. Consequences of this effect for reverse osmosis systems are that the fouling potential at low flux drops dramatically; for ultrafiltration systems it implicates that the rate of fouling increases at high fluxes. The observed effect of flux on the fouling potential has significant implications for fouling potential measurements. Deposition factors in RO systems varied between 0 and 1, depending on location and MFI pore size, which indicates differences in properties of the particles present. Fouling potential results in RO fouling rates of 0.2-1 bar/month depending on the pore size of the membranes used for MFI measurements. The fouling potential of the analysed raw waters is substantially reduced by conventional pre-treatment systems and ultrafiltration: for conventional pre-treatment 37 % - 74 % and ultrafiltration 60 % - 95 %, depending on the location and the MFI pore size.

Desalination as a method to provide clean drinking water has become vital – particularly in a context where drought, water scarcity and rapid quality decrease of water bodies have become an undeniable reality. After more than half a century of membrane-based desalination, fouling and scaling is still a dominant challenge. In membrane technologies, in particular, fouling and scaling are a major issue with respect to design, operation, reliability of the technologies and cost. This textbook covers theory and practice and is intended for designers, operators, consultants, suppliers and students. Principles of ultra- and nanofiltration and reverse osmosis (RO) are discussed, enabling the reader to understand the link between design, operation and fouling and scaling. Fouling (particulate, organic -including algal bloom events, inorganic, and biofouling) and scaling are treated in detail, including parameters to determine fouling and scaling potential of feed waters. Principles of conventional and advanced pre-treatment processes are highlighted and their effect on preventing fouling and scaling. In addition, the process design of RO systems and the recent advances in seawater RO and emerging membrane-based processes for seawater desalination are presented.

The world´s largest demonstrator of a revolutionary energy system in desalination for drinking water production is in operation. MIDES uses Microbial Desalination Cells (MDC) in a pre-treatment step for reverse osmosis (RO), for simultaneous saline stream desalination and wastewater treatment. MDCs are based on bio-electro-chemical technology, in which biological wastewater treatment can be coupled to the desalination of a saline stream using ion exchange membranes without external energy input. MDCs simultaneously treat wastewater and perform desalination using the energy contained in the wastewater. In fact, an MDC can produce around 1.8 kWh of bioelectricity from the energy contained in 1 m3 of wastewater. Compared to traditional RO, more than 3 kWh/m3 of electrical energy is saved. With this novel technology, two low-quality water streams (saline stream, wastewater) are transformed into two high-quality streams (desalinated water, treated wastewater) suitable for further uses. An exhaustive scaling-up process was carried out in which all MIDES partners worked together on nanostructured electrodes, antifouling membranes, electrochemical reactor design and optimization, life cycle assessment, microbial electrochemistry and physiology expertise, and process engineering and control. The roadmap of the lab-MDC upscaling goes through the assembly of a pre-pilot MDC, towards the development of the demonstrator of the MDC technology (patented). Nominal desalination rate between 4-11 Lm-2h-1 is reached with a current efficiency of 40 %. After the scalability success, two MDC pilot plants were designed and constructed consisting of one stack of 15 MDC pilot units with a 0.4 m2 electrode area per unit.This book presents the information generated throughout the EU funded MIDES project and includes the latest developments related to desalination of sea water and brackish water by applying microbial desalination cells.