Reverse osmosis (RO) is currently the most important desalination technology and it is experiencing significant growth. The objective of this paper is to review the historical and current development of RO membrane materials which are the key determinants of separation performance and water productivity, and hence to define performance targets for those who are developing new RO membrane materials. The chemistry, synthesis mechanism(s) and desalination performance of various RO membranes are discussed from the point of view of membrane materials science. The review starts with the first generation of asymmetric polymeric membranes and finishes with current proposals for nano-structured membrane materials. The paper provides an overview of RO performance in relation to membrane materials and methods of synthesis. To date polymeric membranes have dominated the RO desalination industry. From the late 1950s to the 1980s the research effort focussed on the search for optimum polymeric membrane materials. In subsequent decades the performance of RO membranes has been optimised via control of membrane formation reactions, and the use of poly-condensation catalysts and additives. The performance of state-of-the-art RO membranes has been highlighted. Nevertheless, the advances in membrane permselectivity in the past decade has been relatively slow, and membrane fouling remains a severe problem. The emergence of nano-technology in membrane materials science could offer an attractive alternative to polymeric materials. Hence nano-structured membranes are discussed in this review including zeolite membranes, thin film nano-composite membranes, carbon nano-tube membranes, and biomimetic membranes. It is proposed that these novel materials represent the most likely opportunities for enhanced RO desalination performance in the future, but that a number of challenges remain with regard to their practical implementation

Biofilms are major causes of impairment of wound healing and patient morbidity. One of the most common and aggressive wound pathogens isStaphylococcus aureus, displaying a large repertoire of virulence factors and commonly reduced susceptibility to antibiotics, such as the spread of methicillin-resistantS. aureus(MRSA). Bacteriophages are obligate parasites of bacteria. They multiply intracellularly and lyse their bacterial host, releasing their progeny. We isolated a novel phage, DRA88, which has a broad host range amongS. aureusbacteria. Morphologically, the phage belongs to theMyoviridaefamily and comprises a large double-stranded DNA (dsDNA) genome of 141,907 bp. DRA88 was mixed with phage K to produce a high-titer mixture that showed strong lytic activity against a wide range ofS. aureusisolates, including representatives of the major international MRSA clones and coagulase-negativeStaphylococcus. Its efficacy was assessed both in planktonic cultures and when treating established biofilms produced by three different biofilm-producingS. aureusisolates. A significant reduction of biofilm biomass over 48 h of treatment was recorded in all cases. The phage mixture may form the basis of an effective treatment for infections caused byS. aureusbiofilms.

Environmental pressures caused by population growth and consumerism require the development of resource recovery from waste, hence a circular economy approach. The production of chemicals and fuels from organic waste using mixed microbial cultures (MMC) has become promising. MMC use the synergy of bio-catalytic activities from different microorganisms to transform complex organic feedstock, such as by-products from food production and food waste. In the absence of oxygen, the feedstock can be converted into biogas through the established anaerobic digestion (AD) approach. The potential of MMC has shifted to production of intermediate AD compounds as precursors for renewable chemicals. A particular set of anaerobic pathways in MMC fermentation, known as chain elongation, can occur under specific conditions producing medium chain carboxylic acids (MCCAs) with higher value than biogas and broader applicability. This review introduces the chain elongation pathway and other bio-reactions occurring during MMC fermentation. We present an overview of the complex feedstocks used, and pinpoint the main operational parameters for MCCAs production such as temperature, pH, loading rates, inoculum, head space composition, and reactor design. The review evaluates the key findings of MCCA production using MMC, and concludes by identifying critical research targets to drive forward this promising technology as a valorisation method for complex organic waste.