Fouling Mitigation in Forward Osmosis and Membrane Distillation for Desalination

Osmotically assisted reverse osmosis (OARO): Five approaches to dewatering saline brines using pressure-driven membrane processes

Critical aspects of RO desalination: A combination strategy

Natural organic matter (NOM) is a common occurrence in all raw waters (e.g., surface waters, groundwater, and wastewater) that are used for freshwater production. NOM is a leading cause of complications for water treatment systems and is ideally entirely removed early in the process. As an early-stage membrane process, ultrafiltration (UF) can remove the majority of NOM constituents. En revanche, NOM severely fouls UF membranes which can drastically impede the UF process performance. In addition, smaller molecular weight NOM fractions can pass the UF system unhindered and hence, may cause further complications downstream. To address both issues, this paper critically reviews recent publications focusing on enhancing NOM retention and on mitigation of membrane fouling in UF systems. Specifically, the main mitigation routes that are reviewed are UF pre-treatment, in-situ physical and/or chemical cleaning, and membrane enhancement. While several membrane enhancement solutions are promising, the scalability and economic feasibility of these modifications remain questionable. In terms of membrane cleaning, physical solutions are less effective while chemical approaches are more efficient but may cause membrane damage. Of the proposed techniques, multi-process solutions (i.e., combined pre-treatment and UF) are the most promising for NOM retention and prevention of UF membrane fouling. However, optimal operation of multi-process systems is challenging, especially due to the spatio-temporal variability of NOM. Hence, specific focus is given to in-situ, on-line NOM fouling monitoring techniques that can be integrated for dynamic plant operation.

Retention of natural organic matter by ultrafiltration and the mitigation of membrane fouling through pre-treatment, membrane enhancement, and cleaning - A review

Self-doped sulfonated polyaniline ultrafiltration membranes with enhanced chlorine resistance and antifouling properties

The selection of a proper pretreatment for reverse osmosis (RO) systems is essential to produce a high-quality feed water in order to ensure a more sustainable and reliable operation. Traditionally, seawater RO installations have been operated with conventional pretreatments based on single- or two-staged media filtration, and occasionally preceded by coagulation/flocculation processes. In recent years, however, hollow fiber ultrafiltration (UF) technology has increasingly gained acceptance as a viable pretreatment alternative for seawater desalination, due to advantages such as greater capability to cope with fluctuations and high solid loads in raw waters (typical of open intakes), smaller footprint, higher and more consistent filtrate water quality, and higher environmental sustainability, ultimately demonstrating lower total water cost in the long-term operation. In this article, design and operational aspects of the country’s largest integrated UF and RO system to treat seawater in a remote i...

Juan Carlos González

Papers

One-year operational experience with ultrafiltration as pretreatment of seawater reverse osmosis desalination system (Maspalomas-I Plant).