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A photoelectrochemical (PEC) oxidation and flow-electrode capacitive deionization (FCDI) dual system was explored for the effective treatment of brackish water. Two anodic electrodes with electrochemically self-doped TiO2 arrays (blue-mesh/ blue-plate TiO2 nanotube arrays (BM-TNA & BP-TNA)) were fabricated by annealing at 600 °C, and applied for the treatment of a water system. Specifically, the BM-TNA confirmed lower electrical resistance and superior performance under multiple light source (UV-A, -B, and -C). Furthermore, the system generated powerful oxidizing reactive oxygen species (ROS), which were assessed via degradation of eight organic pollutants: bisphenol-A, 4-chlorophenol, cimetidine, sulfamethoxazole, benzoic acid, phenol, nitrobenzene, and acetaminophen. Decomposition efficiency was stable throughout a wide range of pH, and durability of the BM-TNA electrode was demonstrated through long-term operation. Concurrently, optimization of the FCDI process via key operational parameters (electrode mass loading, and applied voltage) achieved superior desalination performance, and specific energy consumption (SEC). In particular, increased mass loading enhanced charge transportation through the formation of stable charge-percolation pathways, leading to improved solution conductance. Finally, the feasibility of the dual system (PEC-FCDI) was verified through complete degradation of the organic substrates and successful desalination of the brackish water. [ABSTRACT FROM AUTHOR]

Fouling indices have been extensively investigated in membrane applications, for evaluating the feed-water fouling potential and providing guidelines for the pretreatment process. For the past few decades, the silt density index (SDI) has been adopted as the most mature fouling index in many seawater reverse osmosis desalination plants. Recently, a modified fouling index (MFI) has gained attention since it compensates for the defects of the SDI. Its publication by ASTM Standard promoted more settlements in practical applications. To gain insight into the use of a membrane-fouling index, this paper reviewed SDI and MFI applications in laboratory-, pilot-, and plant-scale verifications, under conditions likely to be encountered in seawater desalination. The main focus was on the historical development of the fouling indices from theoretical basis to full-scale applications and the identification of future opportunities to expand their reliability in real applications. In particular, the practical implications associated with plant operation were documented to support an in-depth understanding of the MFI values. [ABSTRACT FROM AUTHOR]

The increasing impact of climate change has worsened drought conditions, leading to a surge in the demand for seawater desalination. However, current seawater reverse osmosis (SWRO) desalination technologies are not energy-efficient for handling the high-salinity, high-temperature, and high-turbidity seawater found in the Arabian Gulf. Therefore, a pilot-scale SWRO desalination plant was established to evaluate the new desalination technologies. The pilot plant tested high-performance SWRO membranes, meshed tube filtration (MTF) as a low-energy pretreatment for the high turbidity induced by algal blooms, and membrane capacitive deionization (MCDI) to improve permeate quality. The high-performance SWRO membrane demonstrated exceptional salt rejection and produced permeate quality in the range of 250–455 mg/L from the feed with salinities of 47,500–53,500 mg/L. MTF was effective in controlling turbidity, and the energy consumption was reduced by 77 % compared to the existing pretreatment process. Furthermore, MCDI exhibited similar levels of energy efficiency as brackish water reverse osmosis and may have the potential for future deployment by enhancing process development. Based on the pilot plant results, it is expected that a 100,000–200,000 m3/d SWRO desalination plant will have a specific energy consumption of 3.11–3.13 kWh/m3 for final product water quality at or below 200 mg/L. [Display omitted] • A pilot-scale SWRO desalination plant was used to investigate low-energy technologies. • Developed SWRO membranes significantly decreased feed TDS under normal pressure. • MTF reduced feed turbidity effectively and consumed lower energy compared to DAF. • MCDI demonstrated potential as a substitute for BWRO in two-pass RO systems. • The SEC of SWRO desalination plants was evaluated as 3.11 kWh/m3 through scale-up. [ABSTRACT FROM AUTHOR]

The effects of discharged brine from desalination plants, particularly brine containing algal toxins during harmful agal bloom (HAB) occurrence, are a major concern for marine life and, as a result, human health. Therefore, removing algal toxins from desalination brine is critical for safeguarding both human health and the marine environment. The present work examined the mineralization of domoic acid (DA), an algal toxin, in highly concentrated seawater for the first time using an ultraviolet light activated peroxymonosulfate (UV/PMS) system. Mineralization efficiencies, effects of various anion concentrations, and reaction by-products were investigated. The presence of anions such as chloride, bromide, and bicarbonate reduces the mineralization efficiency of the UV/PMS system, with bromide being the most detrimental. Although DA can be effectively degraded in synthetic seawater (35,000 ppm), total mineralization is not possible within 180 min of reaction time, with only 38.4 %, 44.8 %, and 41 % TOC removal in pH 3, 5, and 7, respectively, when 1 mM of PMS was used. Analyses of treated hypersaline seawater using ultra-high-resolution liquid chromatography coupled with quadrupole time-of-flight mass spectrometry and ion chromatography revealed that DA was completely degraded in synthetic seawater and that, in the presence of algal organic matter, no toxic by-product was generated during the detoxification process. Overall, the UV/PMS system has the potential to be an effective treatment strategy for algal toxins in seawater during HAB events in the SWRO desalination process. [Display omitted] • Domoic acid (DA) mineralization efficiency by UV/PMS system was investigated. • DA can be effectively removed in deionized water and synthetic seawater. • Anions affected the mineralization efficiency with the most detrimental being Br −> Cl −>HCO 3 −. • No halogenation byproducts, chlorates, or bromates were detected after treating DA in hypersaline seawater. [ABSTRACT FROM AUTHOR]

The use of membrane-based technology has evolved into an important strategy for supplying freshwater from seawater and wastewater to overcome the problems of water scarcity around the world. However, the presence of natural organic matter (NOM), including humic substances affects the performance of the process. Here, we present a systematic report on the mineralization of humic acid (HA), as a model for NOM, in high concentration of salts using the ultraviolet light-activated peroxymonosulfate (UV/PMS) system as a potential alternative for HA elimination during membrane-based seawater desalination and water treatment processes. Effects of various parameters such as PMS concentration, solution type, pH, anions, and anion-cation matrix on HA mineralization were assessed. The results show that 100%, 78% and 58% of HA (2 mg/L TOC) were mineralized with rate constants of 0.085 min−1, 0.0073 min−1, and 0.0041 min−1 after 180 min reaction time at pH 7 when 0.5 mM PMS was used in deionized water, sodium chloride solution (35,000 ppm) and synthetic seawater, respectively. The reduced efficiency under saline conditions was attributed to the presence of anions in the system that acted as sulfate and hydroxyl radicals' scavengers. Furthermore, the safety of the treated synthetic seawater was evaluated by analyzing the residual transformed products. Overall, pretreatment with the UV/PMS system mitigated fouling on the RO membrane. [Display omitted] • The UV/PMS system mineralized humic acid (HA) in high salt concentrations. • Mineralization rate was in the order of DI water > NaCl solution > synthetic seawater. • Anions, particularly Cl − and Br − , retarded mineralization efficiency. • There were no halogenated disinfection byproducts produced. • On the RO membrane, significant fouling mitigation was obtained. [ABSTRACT FROM AUTHOR]

Abstract: Forward osmosis (FO) has gained significant research interest due to the wide range of potential applications in desalination and wastewater reuse. However, the FO process being concentration (osmosis) driven has its own intrinsic limitations. Net transfer of water across the membrane occurs until the point of osmotic equilibrium between the draw solution (DS) and the feed solution (FS). Without external intervention, it is impossible to dilute the DS beyond the point of osmotic equilibrium. In this study, the concept of osmotic equilibrium in the FO process is introduced by simulating conditions in a plate-and-frame FO membrane module using established mass transport models. The simulations evaluated the influence of various operating parameters on process performance, assessed in terms of water flux, feed recovery rate and the final concentration of the diluted DS. The counter-current crossflow mode of operation has been observed to be advantageous because it can achieve higher module average water flux, higher feed water recovery rates and higher DS final dilution. Based on the osmotic equilibrium concept and mass balance analysis, a modified equation for the water extraction capacity of a draw solute has been proposed. This study underscores the need for process optimisation for large-scale FO operations. [Copyright &y& Elsevier]

Abstract: The concept of fertiliser drawn forward osmosis (FDFO) desalination lies in the premise that fertilisers that serve as draw solutions (DS) add value to the FDFO product water for fertigation. However, because FDFO desalination is concentration based, the process cannot continue beyond the concentration equilibrium, one of the major limitations of the forward osmosis (FO) process. This results in final FDFO product water that, unless subjected to substantial dilution with fresh water, exceeds the acceptable nutrient concentrations for direct fertigation. In this study, nanofiltration (NF) has been assessed as an integrated process to FDFO desalination, either as a pre-treatment or post-treatment, to reduce the nutrient concentrations in the final product water and thereby allow direct use of the product water for fertigation without further dilution. NF as pre-treatment or post-treatment was found effective in reducing the nutrient concentrations using brackish groundwater (BGW) sources with relatively low total dissolved solid (TDS). However, when using higher TDS BGW sources, the product water still required further dilution or post-treatment before fertigation. NF as post-treatment was found to be more advantageous both in terms of reduced nutrient concentrations in the final product water and energy consumption. [Copyright &y& Elsevier]

With the world's population growing rapidly, pressure is increasing on the limited fresh water resources. Membrane technology could play a vital role in solving the water scarcity issues through alternative sources such as saline water sources and wastewater reclamation. The current generation of membrane technologies, particularly reverse osmosis (RO), has significantly improved in performance. However, RO desalination is still energy intensive and any effort to improve energy efficiency increases total cost of the product water. Since energy, environment and climate change issues are all inter-related, desalination for large-scale irrigation requires new novel technologies that address the energy issues. Forward osmosis (FO) is an emerging membrane technology. However, FO desalination for potable water is still a challenge because, recovery and regeneration of draw solutes require additional processes and energy. This article focuses on the application of FO desalination for non-potable irrigation where maximum water is required. In this concept of fertiliser drawn FO (FDFO) desalination, fertilisers are used as draw solutions (DS). The diluted draw solution after desalination can be directly applied for fertigation without the need for recovery and regeneration of DS. FDFO desalination can make irrigation water available at comparatively lower energy than the current desalination technologies. As a low energy technology, FDFO can be easily powered by renewable energy sources and therefore suitable for inland and remote applications. This article outlines the concept of FDFO desalination and critically evaluates the scope and limitations of this technology for fertigation, including suggestions on options to overcome some of these limitations. [ABSTRACT FROM AUTHOR]

A forward osmosis (FO) and reverse osmosis (RO) hybrid process was examined for sustainable direct potable reuse (DPR) of wastewater through integration with seawater desalination. Using real wastewater secondary effluent, feasibility of the FO-RO system for DPR was systematically assessed by investigating fouling behavior and its reversibility and evaluating the quality of produced water. Its technical advantages were further verified by the ease of fouling control. The results for the silt density index (SDI) and the modified fouling index (MFI) clearly demonstrated that FO significantly alleviated the potential of subsequent RO membrane fouling, leading to sustainable RO operation for wastewater reuse. Permeate water flux in FO was significantly recovered by physical cleaning. However, biopolymer-like substances was persistently accumulated on the FO membrane surface even after repeated cleaning, suggesting that pretreatment for removal of such substances causing irreversible fouling are required for long-term operation of the FO-RO process. Lastly, the final product water satisfied all 58 components of the quality standards for drinking water in Korea, confirming that the double barrier provided by the FO and RO membranes was adequate for DPR. [ABSTRACT FROM AUTHOR]

The demand for ultrapure water (UPW) has been increased over the past decades. UPW production now occupies an almost equivalent position with seawater desalination in the world water market, fulfilling the demands of various industrial purposes. As an extremely low level of contaminants is required, the typical UPW production system combines 5 to10 purification technologies including ultrafiltration (UF), reverse osmosis (RO) and ion exchanger (IX). In recent years, RO has been at the forefront of this elaborate process as the majority of impurity rejections is carried out with it. This study provides a comprehensive review of the rising role of RO to satisfy the technical requirements in the UPW sector, with an emphasis on electronic industrial applications. The major transitions in recent UPW production are first reviewed: 1) ever-increasing water quality demand, 2) introduction of electrochemical processes into the water polishing stage and 3) UPW waste reclamation, all of which emphasize the enhanced responsibility of RO for producing cleaner permeate. Additionally, the noteworthy insights of RO technologies for the purpose of UPW are summarized, specifically focusing on RO configurations appropriate for UPW, scaling mitigation techniques for high recovery operation, and cleaning methods for maintenance. Lastly, this review concludes with future research directions for UPW production systems to achieve successful implementation. [ABSTRACT FROM AUTHOR]

Pressure retarded osmosis (PRO) harnesses salinity gradient energy through the mixing of freshwater and saltwater, addressing the demand for sustainable energy sources. PRO typically utilizes river water or secondary wastewater as the feed solution, paired with seawater reverse osmosis (SWRO) brine as the draw solution. However, the limited availability of low-saline water presents a significant obstacle to energy generation. Therefore, the feasibility of a high-pressure PRO process utilizing seawater as the feed solution and hypersaline water as the draw solution was assessed to generate sustainable blue energy. Seawater has the potential to achieve the maximum extractable Gibbs-free energy through high-pressure PRO by maximizing the feed/draw ratio. The performance of the high-pressure PRO was theoretically evaluated, resulting in a tenfold increase in specific energy production compared to conventional SWRO-PRO due to the higher feed/draw ratio. However, high hydraulic pressure increased the membrane structural parameter and further reduced water flux and power density due to significant internal concentration polarization. Nevertheless, the high-pressure PRO process can achieve a power density exceeding 84 W/m2 when the structural parameter remains below 100 μm. The implications of the high-pressure PRO were further discussed to advance the concept of a blue circular economy, enhance environmental resilience, and promote sustainability. [Display omitted] • Feasibility of high-pressure PRO was investigated using seawater/hypersaline water. • Higher feed/draw ratio boosted energy production in the PRO process. • Seawater was assessed as a feed for high-pressure PRO for blue energy generation. • High-pressure operation raised the structural parameter reducing power density. • High-pressure PRO achieved >80 W/m2 at structural parameter <100 μm. [ABSTRACT FROM AUTHOR]

Brine management systems are imperative for sustainable water supply and for securing valuable resources from desalination plants. The utilization of membrane brine concentrators has recently been focused on because of their high energy and cost efficiencies compared with those of thermal brine concentrators. In this paper, we investigated the recent candidates of membrane concentrators in terms of their future potential in brine management systems and categorized the types of utilized membranes into two groups: single solution passing (SSP)-type membranes and double solution passing (DSP)-type membranes. The current membrane technologies for manufacturing these types of membranes were critically analyzed, and future directions for membrane development towards efficient brine management systems were suggested. SSP-type membranes and their accompanying systems should be durable at pressures higher than 230 bar to utilize membrane brine concentrators. On the other hand, DSP-type membranes should exhibit high-pressure durability (higher than 40 bar) and low structure parameters (less than 50 μm). This study examines the current status of membrane systems and presents the technical specifications of membranes required for membrane brine management systems. [Display omitted] • Brine management systems using membrane concentrators are summarized and analyzed. • Two types of membranes are classified in the applications of membrane concentrators. • The required specifications of membranes are determined for membrane concentrators. • Future directions for membrane development are suggested towards brine management. [ABSTRACT FROM AUTHOR]

A series of MFI (modified fouling index) measurements were performed to evaluate and predict organic fouling potential and mechanism in seawater reverse osmosis (SWRO) desalination, by employing a multiple membrane array system (MMAS) in which microfiltration (MF), loose and tight ultrafiltration (UF) membranes were configured in a consecutive manner to determine the MFIs of particles, colloids, and organics. The results suggested that organic fractions manifested by colloid-MFI should be removed to control organic fouling effectively, as the organic fraction with MW ranging from 30 to 300 kDa led to the most severe fouling in RO experiments. The variations in fouling potential according to solution conditions (i.e., pH and Ca 2 + ) were also more accurately evaluated using multiple MFIs than with conventional SDI. This work demonstrated that the current fouling index, relying on a single membrane, could be improved by utilizing multiple membranes with different characteristics (e.g., pore size and hydrophobicity) to assess the fouling behavior of specific organic fractions. [ABSTRACT FROM AUTHOR]

Abstract: Fertiliser-drawn forward osmosis (FDFO) desalination has been recently studied as one feasible application of forward osmosis (FO) for irrigation. In this study, the potential of membrane scaling in the FDFO process has been investigated during the desalination of brackish groundwater (BGW). While most fertilisers containing monovalent ions did not result in any scaling when used as an FO draw solution (DS), diammonium phosphate (DAP or (NH4)2HPO4) resulted in significant scaling, which contributed to severe flux decline. Membrane autopsy using scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDS), and x-ray diffraction (XRD) analysis indicated that the reverse diffusion of DAP from the DS to the feed solution was primarily responsible for scale formation during the FDFO process. Physical cleaning of the membrane with deionised water at varying crossflow velocities was employed to evaluate the reversibility of membrane scaling and the extent of flux recovery. For the membrane scaled using DAP as DS, 80–90% of the original flux was recovered when the crossflow velocity for physical cleaning was the same as the crossflow velocity during FDFO desalination. However, when a higher crossflow velocity or Reynolds number was used, the flux was recovered almost completely, irrespective of the DS concentration used. This study underscores the importance of selecting a suitable fertiliser for FDFO desalination of brackish groundwater to avoid membrane scaling and severe flux decline. [Copyright &y& Elsevier]

Abstract: A hybrid system that combines forward osmosis with a reverse osmosis seawater desalination process could reduce both energy requirements and environmental impacts by osmotic dilution of the seawater and concentrated brine with an impaired low salinity stream, such as treated wastewater effluent. In this study, we investigate the membrane fouling behavior in forward osmosis under conditions simulating the osmotic dilution process and the use of hydrodynamic methods without the use of cleaning chemicals, to control membrane fouling. Fouling runs with seawater or SWRO brine draw solution and deionized (DI) water feed solution showed insignificant water flux decline, which implies negligible effect of particulate and organic matter in the seawater/brine on fouling of the FO membrane support layer. Fouling of the membrane active layer was evaluated by using an enriched synthetic wastewater effluent containing a mixture of inorganic and organic foulants, focusing on the impact of permeate drag force on fouling layer formation. Our results demonstrate that higher permeate water flux causes an increase in concentration build-up of foulants at the membrane surface, thereby forming a dense inorganic/organic combined fouling layer during FO fouling runs. We also examined three hydrodynamic methods for minimizing FO membrane fouling in the osmotic dilution process: (1) applying shear force on the membrane surface by increasing the cross-flow velocity, (2) using a feed-channel spacer to induce turbulence, and (3) employing pulsed flow to remove foulants from the membrane surface. Our results show that these hydrodynamic methods substantially reduce fouling and flux decline rate. [Copyright &y& Elsevier]

Abstract: Forward osmosis (FO) is a novel and emerging low energy technology for desalination. It will be particularly more attractive, if the draw solution separation and recovery are not necessary after FO process. The application of this new concept is briefly described here in this paper for the desalination of saline water for irrigation, using fertilizer as a draw agent. Instead of separating the draw solution from desalinated water, the diluted fertilizer draw solution can be directly applied for fertigation. We report the results on the commonly used chemical fertilizers as FO draw solution. Based on the currently available FO technology, about nine different commonly used fertilizers were finally screened from a comprehensive list of fertilizers and, their performances were assessed in terms of pure water flux and reverse draw solute flux. These results indicate that, most soluble fertilizers can generate osmotic potential much higher than the sea water. The draw solutions of KCl, NaNO3 and KNO3 performed best in terms of water flux while NH4H2PO4, (NH4)2HPO4, Ca(NO3)2 and (NH4)2SO4 had the lowest reverse solute flux. Initial estimation indicates that, 1kg of fertilizer can extract water ranging from 11 to 29L from sea water. [Copyright &y& Elsevier]

Vacuum-membrane distillation (VMD) is a membrane-based separation process that utilizes hydrophobic membrane and vacuum pressure to distillate hot saline feed stream into high purity fresh water. Despite the recent interests in the VMD, comprehensive membrane characterization and theoretical performance analysis relevant to system-level scales are limited. In this work, we present experimental and theoretical investigation of a commercial high performance PTFE membrane for the VMD application. With a careful examination of the membrane properties with a module that captures both hydrodynamic and thermal behaviors with coupled heat and mass transfer analysis, we evaluated the membrane distillation performances. Because laboratory observation does not elucidate larger scale performances, experimentally validated theoretical model is used to evaluate the performances of a PTFE membrane-based single-stage VMD system with a module length of up to 10 m at salinities of 30 and 60 g/kg. Influence of various operating conditions, such as feed temperatures, mass flow rates, and vacuum pressures, as well as temperature and concentration polarizations on the desalination performances are examined. We show that the PTFE membrane investigated in this study can generate high permeate fluxes at the system-scale, a promising candidate membrane for the VMD application. • Experimental and theoretical study of a high performance PTFE membrane for a VMD application. • The experimental module was carefully designed to capture both hydrodynamic and thermal behaviors. • Membrane mass transfer performances were evaluated with a high-fidelity theoretical model. • Performances of a system-level VMD module with various operating conditions were predicted. [ABSTRACT FROM AUTHOR]

Owing to the significant increase in seawater desalination, seawater exhibiting extreme conditions of high salinity and high temperature cannot be avoided in the production of fresh water. Although seawater reverse osmosis (SWRO) is one of the most energy-saving desalination technologies, it might not be favorable for treating extreme seawater due to the operational limitations associated with the single-stage SWRO configuration. To overcome these limitations, the applicability of two-stage SWRO was examined. The recovery of single-stage SWRO was limited to 31% for stable operation, whereas two-stage SWRO, utilizing pressure exchangers as energy recovery devices, achieved 34% recovery for the same number of pressure vessels. Furthermore, the maximum water fluxes in the front SWRO elements were reduced under the design constraints of the two-stage configuration than that of the single-stage configuration. The two-stage SWRO system was energy-efficient with high recovery; however, under extreme conditions, the permeate quality was similar to that of single-stage SWRO. To improve the applicability of two-stage SWRO, internally staged design (ISD) and split partial second pass (SPSP) can be adopted. ISD can reduce water fluxes in the front elements, increasing system recovery, whereas SPSP design enables the reverse osmosis system to produce high-quality permeate with low additional energy. Unlabelled Image • SWRO performance was evaluated for high-salinity and high-temperature seawater. • Single-stage SWRO suffered from low recovery and high water flux for front elements. • Two-stage SWRO achieved higher recovery and exhibited lower front water flux. • ISD further increased recovery by reducing water fluxes of front elements. • SPSP improved product quality and energy efficiency by treating rear permeate. [ABSTRACT FROM AUTHOR]

Although seawater desalination is becoming an important technology for freshwater production, the presence of a high concentration of bromide in the seawater presents a major challenge. Bromide is one of the major inorganic precursors for the formation of disinfection by-products such as bromate, which is highly regulated due to its toxicity and carcinogenicity. Hence, a significant reduction of bromide ions is required prior to water disinfection. In Australia, all the desalination plants have to operate a two-stage reverse osmosis system to ensure effective bromide removal, which adds significant cost to the desalination system. In this study, a pilot-scale membrane capacitive deionisation (MCDI) was investigated as a potential alternative to the 2nd stage RO in seawater desalination. Moreover, strategies to enhance water recovery in MCDI was also carried out by using lower flow rates and shorter duration during the desorption stage. In order to reduce energy consumption in MCDI, a combined short-circuit and reverse polarity desorption is introduced. The results showed that MCDI can effectively remove bromide and dissolved salt at a much lower energy consumption compared with membrane process and that MCDI can be operated to achieve high water recovery without increasing the total energy consumption. Unlabelled Image • Bromide and TDS removal in pilot-scale MCDI was investigated • Use of lower desorption flow rate can significantly increase water recovery • Shorter desorption time can result in increased water recovery • A combined short-circuit followed by reverse voltage desorption can be effective [ABSTRACT FROM AUTHOR]

While single-stage is the general configuration for seawater reverse osmosis (SWRO), the two-stage design can increase the overall recovery of an SWRO system. Due to its high-recovery operation, the specific energy consumption (SEC) of two-stage SWRO is higher than that of single-stage. Thus, the two-stage configuration has not been extensively applied in the current desalination market. In contrast, recent studies have reported that the two-stage design can lower the SEC of SWRO compared to that of single-stage. However, the analyses were biased towards SEC, and the practical design aspects (e.g., permeate quality, water flux, and design ratios) were not systemically considered. Thus, this study examines the applicability of a two-stage SWRO system with a capacity of 100,000 m3/d that employs 1200 pressure vessels (PVs). Two-stage SWRO actually consumed a greater amount of energy than that of single-stage for typical SWRO recovery with the same number of PVs. In contrast, single- and two-stage SWRO produced permeate similar in quality, while the two-stage exhibited superior water-flux distribution along the PVs. Additionally, optimal ratios of permeate flow rate and number of PVs were determined by energy recovery devices type, where the ratio of 1:2 was selected for the reverse osmosis system with a pressure exchanger and 2:1 for that with a Pelton turbine. Considering SEC and other operational aspects, the use of two-stage SWRO was feasible at a 50–70% recovery rate. Image 1 • Two-stage SWRO is fundamentally analyzed and optimized for seawater desalination. • SEC of two-stage SWRO is higher than that of single-stage in typical recovery. • Water quality of single- and two-stage SWRO is similar at the same average flux. • Optimal ratios of permeate flow rate and number of PVs vary depending on ERD types. • Two-stage SWRO is more energy-efficient at a high recovery rate (e.g., 50–70%). [ABSTRACT FROM AUTHOR]

Preoxidation is gaining spotlight in the mitigation of ultrafiltration (UF) membrane fouling caused by algal organic matter (AOM). Although it is known to be beneficial in freshwater, its applicability in seawater treatment has barely been explored. This study first evaluated the effect of UV/permonosulfate (PMS) oxidation for UF process against marine harmful algal blooms (HAB). The transition of AOM released from Pseudo Nitzchia was investigated which produces a neurotoxin, domoic acid (DA). Specifically, UV light emitting diodes (LED) were employed as UV source. The results indicated UV-LED/PMS treatment effectively reduces the fouling potential of AOM. However, the participation of abundant chloride ions generated free chlorine and disinfection byproducts, thus, PMS addition below 0.5 mM was suggested for seawater applications. With respect to PMS 0.5 mM, TOC and cake layer resistance were reduced by 10% and 85%, respectively, and this was followed by significant improvements in water permeability, flux reversibility and permeate quality of UF process. Furthermore, PMS exhibited significant reactivity for decomposing DA achieving rapid disappearance of 1 ppm of DA within a minute. The aforementioned results encourage the use of PMS as a bulk oxidant in seawater treatment to simultaneously mitigate membrane fouling and improve permeate quality. Unlabelled Image • The impact of UV-LED/PMS preoxidation was assessed against marine AOM fouling. • Despite abundant Cl− ions, it was effective to be applied in seawater condition. • Preoxidation greatly mitigated both reversible and irreversible UF membrane fouling. • UV-LED/PMS preoxidation is also beneficial to reduce toxic substance, domoic acid. • To control moderate amounts of free Cl and THMs, [PMS] < 0.5 mM was suggested. [ABSTRACT FROM AUTHOR]

Abstract The extraordinarily high salinity of seawater (e.g., Gulf seawater) requires a seawater desalination system such as two-pass reverse osmosis (RO). However, the auxiliary brackish water reverse osmosis (BWRO) treatment for satisfying the produced water quality significantly increases the energy consumption. This study first proposes a novel concept, integrating membrane capacitive deionization (MCDI) and reverse electrodialysis (RED) with RO to treat high-salinity seawater with enhanced energy efficiency. In this hybrid system, MCDI successfully substituted for BWRO and met the required water quality regulations by the World Health Organization (WHO). Moreover, RED recovered 33% of the energy from discharges. The optimum operating conditions of the RO-MCDI hybrid system were found to be 0.8 V of applied voltage on MCDI at 50% and 80% of water recovery for the first pass RO and the second pass MCDI, respectively. In particular, the great flexibility of MCDI in removal efficiency could generate notable synergistic effects with RED, which could lead to better energy efficiency. Consequently, under optimized operation conditions, the energy consumption of this novel RO-MCDI-RED hybrid system was respectively reduced by 39.0% and even 16.8% compared to that of a typical two-pass RO system without and with RED. Graphical abstract Unlabelled Image Highlights • RO-MCDI-RED hybrid system was newly proposed. • MCDI exhibited satisfactory TDS removal efficiency as the second pass process. • Low voltage for MCDI and high water recovery for RO and MCDI were recommended. • Proposed hybrid system was more energy efficient compared to the two pass RO system. • With recent advances on MCDI and RED, energy efficiency could be further improved. [ABSTRACT FROM AUTHOR]

Abstract Capacitive deionization (CDI) has attracted a great attention as a promising desalination technology, and studies on CDI have increased significantly in the last ten years. However, there have been no guidelines for developing strategies involving CDI technology for specific applications. Therefore, our work presents a critical review of the recent advances in CDI to meet the technical requirements of various applicable areas, with an emphasis on hybrid systems. This paper first summarizes the major developments made on novel electrode materials for CDI for brackish water desalination. Then, CDI and reverse osmosis (RO) integrated systems are critically reviewed for both ultrapure water production and wastewater treatment. Additionally, the applicability of CDI on various industrial processes is discussed, covering two distinct topics: (1) water softening and (2) selective removal of valuable heavy metals and nutrients (nitrate/phosphate). Lastly, recent improvements on the energy efficiency of CDI processes are delineated, specifically focusing on energy recovery and hybridization with energy producing technology, such as reverse electrodialysis (RED) and microbial fuel cells (MFC). This review paper is expected to share the practical experience of CDI applications as well as to provide guidelines for electrode material development for each specific application. Graphical abstract Unlabelled Image Highlights • The practical applications of CDI technology were reviewed extensively. • Technological guidelines were delineated for expanding the use of CDI. • CDI-RO hybrid system exhibited promising results in UPW and wastewater treatment. • CDI was successively applied to water softening, heavy metal and nutrients removal. • Energy efficiency could be further improved with energy recovery or hybrid system. [ABSTRACT FROM AUTHOR]

An osmotic dilution process of forward osmosis (FO) and reverse osmosis (RO) was applied at pilot-scale to integrate wastewater treatment with seawater desalination in a coal-fired power plant. FO was osmotically driven by seawater used as cooling water. FO-treated wastewater was diluted with seawater and then further processed by RO. Seasonal variation in water flux, fouling behavior and reversibility, and energy consumption in both FO and RO were systematically evaluated during 5 months of pilot operation. The FO water flux, which declined due to the organic fouling induced by the wastewater from the coal-fired power plant, was readily recovered by physical cleaning. The integrated FO-RO dilution process was able to reduce the RO fouling potential through FO treatment of wastewater, significantly decreasing SDI value to 1.5 ± 0.1. This study also reported energy consumption data, to our knowledge for the first time, at pilot scale operation of FO-RO dilution process, and showed that total energy consumption for desalinating the diluted feed, including wastewater reclamation by FO, was 15% less than that of typical seawater desalination by RO. The results of this FO-RO pilot study demonstrated that sustainable FO-RO operation can be achieved in the treatment of power plant wastewater owing to easy fouling control, low energy consumption, and superior final water quality. [ABSTRACT FROM AUTHOR]

Recently, a modified fouling index (MFI) is published on ASTM, and thus, is expected to become a standard method for evaluating fouling potential, as a supplement to silt density index (SDI). Employing membranes with smaller pore size in MFI measurements has been continuously suggested in many previous studies. However, there was a lack of practical studies verifying the usefulness of MFI. In this study, the applicability of multiple MFIs (i.e., MFI 0.45 , MFI-UF 100 kDa and MFI-UF 10 kDa ) were evaluated at a full-scale UF/RO seawater desalination plant located in the Middle East. For a year, MFIs were measured with RO feed water and the results were correlated with increments in differential pressure (DP) of RO process. Regression analysis was conducted in order to find out whether the fouling index could predict RO performance deterioration. The observed MFIs clearly showed correlation with DP variation, while SDI and water quality parameters (e.g. turbidity and UV 254 ) exhibited relatively low accordance. Particularly, MFI-UF 100 kDa was the most sensitive, indicating that colloidal fouling is the main cause of fouling in SWRO desalination. The regression results were reconfirmed through specific events where feed water quality was severely changed due to red tide or ship movement at intake. These events provided unconventional feed water characteristics, but similar trend was observed that MFI-UF 100 kDa was most sensitive. The application of MFI in an actual plant provided valuable contribution for the further advancement of MFI measurements. [ABSTRACT FROM AUTHOR]

Reverse osmosis (RO) process using a thin-film composite (TFC) membrane is a current leading technology for water desalination. The polyamide permselective layer of the TFC membrane enables salt retention and water permeation, with the ultimate goal of minimizing the permselective layer thickness for maximum energy efficiency. Yet this drive towards reducing the permselective layer thickness is greatly handicapped by the interfacial polymerization (IP) approach used to fabricate TFC membranes. We present layered interfacial polymerization (LIP) as a new paradigm for fabricating TFC membranes with unprecedented nanoscale control in the permselective layer thickness and smoothness, coupled with the advantage of industrial scale manufacturability. Membranes fabricated using LIP demonstrated high NaCl rejection necessary for water desalination, with water permeance ≈ 86% and permselectivity ≈ 450% greater than that of the membranes prepared using conventional IP and comparable water permeance and permselectivity ≈ 17% higher than that of commercial RO membranes. In addition, the unique smooth morphology of the LIP-assembled membrane surface enabled to mitigate the membrane fouling compared to the characteristic rough surface of the conventional IP-assembled membrane. [ABSTRACT FROM AUTHOR]

Harmful algal blooms (HABs) are a major barrier to the stable and efficient operation of seawater reverse osmosis (SWRO) desalination plants. Although the intensity varies regionally, the occurrence of HABs impairs plant operation through severe particulate, organic, and biological fouling of both pretreatment and RO systems. As a result, considerable effort has been put into developing and optimizing pre-treatment techniques to mitigate these problems. This study reviews the historical changes and current status of pretreatment applications based on >110 datasets for large SWRO desalination plants. Chronological analysis underscores the increasing trend in the operation of dissolved air flotation and ultrafiltration systems since severe HABs in the Middle East from 2008 to 2009. The impact of HAB characteristics on system performance was also analyzed, and the efficiency of current pretreatment systems for the removal of HABs was evaluated, along with proposals for operational guidelines. Finally, future strategies for i) intelligent monitoring and prediction of HABs, ii) improvement of unit processes for the removal of algal organic matter, and iii) utilization of algal biomass to alleviate environmental impact were systematically delineated for smarter, safer, and greener operation of future SWRO desalination plants in response to the occurrence of HABs. [Display omitted] • Review on the impact of harmful algal blooms (HABs) on seawater desalination • Analysis of >110 datasets of full-scale SWRO desalination plants • Historical trends and current practice of pretreatment applications • Guidelines for pretreatment operation under HABs occurrences • Future operational directions for smarter, safer and greener desalination practice [ABSTRACT FROM AUTHOR]

The pilot-scale fertiliser driven forward osmosis (FDFO) and nanofiltration (NF) system was operated in the field for about six months for the desalination of saline groundwater from the coal mining activities. Long-term operation of the FDFO-NF system indicates that simple hydraulic cleaning could effectively restore the water flux with minimal chemical cleaning frequency. No fouling/scaling issues were encountered with the NF post-treatment process. The study indicates that, FDFO-NF desalination system can produce water quality that meets fertigation standard. This study also however shows that, the diffusion of solutes (both feed and draw) through the cellulose triacetate (CTA) FO membrane could be one of the major issues. The FO feed brine failed to meet the effluent discharge standard for NH 4 + and SO 4 2+ (reverse diffusion) and their concentrations are expected to further increase at higher feed recovery rates. Low rejection of feed salts (Na + , Cl − ) by FO membrane may result in their gradual build-up in the fertiliser draw solution (DS) in a closed FDFO-NF system eventually affecting the final water quality unless it is balanced by adequate bleeding from the system through NF and re-reverse diffusion towards the FO feed brine. Therefore, FO membrane with higher reverse flux selectivity than the CTA-FO membrane used in this study is necessary for the application of the FDFO desalination process. [ABSTRACT FROM AUTHOR]

A hybrid process of pressure retarded osmosis (PRO) and reverse osmosis (RO) has a great potential for successfully integrating wastewater reclamation with seawater desalination, which can achieve several operational goals simultaneously including augmenting water resources, providing multiple barriers for wastewater purification, seawater dilution for lowering energy use as well as capital cost, osmotic power generation, and less environmental impact. The low energy use of a PRO–RO process was demonstrated by assessing specific energy consumption (SEC). However, a substantial flux decline was observed owing to the susceptibility of PRO to membrane fouling. Particularly, inorganic fouling was pronounced within the support layer, which was hardly reversible by hydrodynamic methods such as physical flushing and osmotic backwashing. Lastly, the anti-scaling pretreatment was shown to be very effective for lessening inorganic scaling within the support layer, suggesting that a PRO–RO hybrid process could be successfully applied with optimized fouling control strategies in PRO. [ABSTRACT FROM AUTHOR]

Adequate dilution of fertiliser draw solution (DS) during fertiliser drawn forward osmosis (FDFO) desalination is important to meet nutrient concentration level for direct fertigation. The maximum DS dilution, however, occurs until the point of osmotic equilibrium between DS and feed solution (FS) thereby limiting the extent of DS dilution. Post-treatment such as nanofiltration (NF) process is required to reduce the fertiliser concentration. In this study however, pressure assisted fertiliser drawn osmosis (PAFDO) process was investigated to enhance DS dilution beyond the point of osmotic equilibrium and potentially eliminate NF post-treatment. The hydraulic pressure applied enhanced water flux significantly depending on the pressure. The applied pressure was found more effective at lower DS concentrations than at higher DS concentrations. For example, when a pressure of 10 bar was applied to 10 g/L NaCl FS with 0.1 M (NH 4 ) 2 SO 4 DS, the water flux increased by 1928% against 38% with 3.0 M (NH 4 ) 2 SO 4 DS. This additional water flux could dilute the fertiliser DS beyond the osmotic equilibrium concentrations thereby meeting the fertigation standard. PAFDO could potentially eliminate NF post-treatment significantly helping reduce the footprint and capital cost. However, the effective gain in water flux due to applied pressure at osmotic equilibrium decreased with the increase in the FS concentrations. [ABSTRACT FROM AUTHOR]

Abstract: Forward osmosis (FO) is an emerging technology for low energy desalination. Amongst the many other factors, temperature of the draw solution (DS) and feed solution (FS) plays an important role in influencing the performance of the FO process. In this study, the influence of the temperature and the temperature difference on the performance of FO process has been studied in terms of water and solute fluxes. Temperature difference was maintained by elevating only one of the solutions (either DS or FS). The results indicate that, water flux on average increases by up to 1.2% for every degree rise in temperature from 25°C to 35°C while this rise is 2.3% from 25°C to 45°C. Providing a temperature difference by elevating only the DS also enhanced the water flux significantly, although it was lower than FO process operated at isothermal conditions. However, elevating only the temperature of FS did not significantly improve the water flux although it was higher than the FO process operated at 25°C. This has significant implications in FO process because the total mass of the DS requiring heat energy is significantly less than the total FS used. The influences of temperature in the FO process such as through changes in the thermodynamic properties of the solutions and the various concentration polarisation effects are also explained in details. [Copyright &y& Elsevier]

In fertilizer-drawn forward osmosis (FDFO) desalination, the final nutrient concentration (nitrogen, phosphorus, potassium (NPK)) in the product water is essential for direct fertigation and to avoid over fertilization. Our study with 11 selected fertilizers indicate that blending of two or more single fertilizers as draw solution (DS) can achieve significantly lower nutrient concentration in the FDFO product water rather than using single fertilizer alone. For example, blending KCl and NH4H2PO4 as DS can result in 0.61/1.35/1.70 g/L of N/P/K, which is comparatively lower than using them individually as DS. The nutrient composition and concentration in the final FDFO product water can also be adjusted by selecting low nutrient fertilizers containing complementary nutrients and in different ratios to produce prescription mixtures. However, blending fertilizers generally resulted in slightly reduced bulk osmotic pressure and water flux in comparison to the sum of the osmotic pressures and water fluxes of the two individual DSs as used alone. The performance ratio or PR (ratio of actual water flux to theoretical water flux) of blended fertilizer DS was observed to be between the PR of the two fertilizer solutions tested individually. In some cases, such as urea, blending also resulted in significant reduction in N nutrient loss by reverse diffusion in presence of other fertilizer species. [ABSTRACT FROM AUTHOR]

Abstract: A new approach to evaluate the fouling potential of feed waters for reverse osmosis (RO) and nanofiltration (NF) practices was systematically investigated. A multiple membrane array system (MMAS) was developed, in which microfiltration (MF), ultrafiltration (UF), and nanofiltration (NF) membranes were connected in series. This system was designed to separate the target foulants in the feed water and evaluate the fouling potential of a targeted foulant. More specifically, particulate, colloids, and organic matters were separated by MF, UF, and NF membranes in a consecutive manner, and the modified fouling index (MFI) was measured during each separation. The resulting three MFI values are Particle-MFI, Colloid-MFI, and Organic-MFI, and presented schematically in a triangle manner. The results demonstrated that fouling potentials of various feed waters (e.g., seawaters pretreated by various pretreatment options as well as raw seawater) evaluated by the MMAS were much more accurate and informative compared to those predicted by conventional silt density index (SDI) and single MFI. The fouling potentials determined by the MMAS precisely reflected changes in feed water quality by different pretreatment options (i.e., sand filtration, microfiltration, and ultrafiltration), while SDI measurements were not sensitive enough to detect these variations. It was also shown that the fouling potentials evaluated by the MMAS were well correlated with the actual flux-decline rates determined by lab-scale RO fouling experiments simulating seawater desalination, suggesting that the MMAS could provide a better way to predict fouling potential and guidance to select proper pretreatment processes. [ABSTRACT FROM AUTHOR]

An osmotic dilution process of hybrid forward osmosis (FO) and reverse osmosis (RO) was applied at pilot-scale to integrate wastewater treatment with seawater desalination in a municipal wastewater treatment plant. The aim of this study is to expand the understanding of multiple FO fouling indexes (i.e., MFI-UF and ORI) to not only obtain insight on fouling characteristics of the FO process but also optimize the operation of the osmotic dilution process. The correlation between the fouling indexes and performance of the FO membrane (i.e., transmembrane inlet pressure (TMIP), differential pressure (DP)) was first validated based on the operation data from the seven-month pilot run. MFI-UF was then selected for measuring the fouling potential according to the pretreatment process (or source water), whereas ORI was obtained for optimizing the cleaning protocol of the FO process to support the stable operation of the FO plant. The sensitivity analysis of the seasonal effect verified the correlation between MFI-UF and FO performance. The results of this study are expected to provide practical insight and technical guidelines to FO based plant engineers/operators. Image 1 • Applicability of multiple FO fouling indexes was validated at pilot scale. • Long-term performance was assessed by adopting different pretreatment strategies. • A close relationship between MFI-UF and FO ΔDP was observed. • ORI was able to predict the FO TMIP precisely. • MFI-UF and ORI can be applied as plant–assistance criteria for FO process. [ABSTRACT FROM AUTHOR]

In this study, we report on a solar membrane distillation (MD) system with a 5-stack Ti/MgF 2 solar absorber adapted as a heat source under actual weather conditions. The 5-stack Ti/MgF 2 solar absorber showed light absorption of 85% over the wavelength range from 0.3 to 2.5 μm. This consequently induced greater heat and a two-fold greater water heating capability up to 80 °C for water in a closed water tank without insulation under a 1-sun illumination. The enhanced solar absorption of the Ti/MgF 2 solar absorber showed a 12% improvement in permeate flux of the integrated MD system compared with a system without a solar absorber. Under actual weather conditions, the solar DCMD system with the Ti/MgF 2 solar absorber successfully produced distillate water in the range of 0.51–4.78 L/m2·day depending on weather conditions. Despite unfavorable solar irradiance conditions in autumn, the integrated DCMD system with the Ti/MgF 2 solar absorber proved superior to a conventional commercial evacuated-tube solar collector in terms of daily production of distillate water and solar energy requirements for certain amounts of distillate. Unlabelled Image • A solar DCMD system with a 5-stack Ti/MgF 2 solar absorber was performed. • A Ti/MgF 2 solar absorber exhibited enhanced solar-thermal performance. • Distillate water successfully produced under actual weather conditions. • Compatibility to commercial solar collector was evaluated. [ABSTRACT FROM AUTHOR]

A new meshed tube filtration (MTF) process was developed and assessed as a low energy-consuming pretreatment process that withstands algal blooms (i.e., red tide). This process can potentially replace the dissolved air flotation (DAF) process in typical seawater reverse osmosis (SWRO) desalination plants. Two marine microalgae species, namely C. polykrikoides and T. suecica , were first cultivated and then utilized to simulate algal bloom conditions in the lab-scale filtration experiments. The algal matter was coagulated and circulated by aeration in the MTF system that was filled with cylindrical polypropylene meshed tubes with ciliary ends and had the ability to capture coagulated algae in an effective manner. The efficiency of the MTF process to remove algal cells was significantly enhanced by optimizing the coagulant dose and the aeration rate. In order to further verify the MTF performance, DAF experiments were conducted, under similar conditions, for the comparison of algal removal effectiveness and energy consumption rates. The results showed high removal rates of algal cells as well as turbidity for MTF, although only a limited reduction of algal organic matter (AOM) was observed. When DAF was operated at energy consumption levels equivalent to MTF, its algae removal rate was lower than that of MTF. Furthermore, under optimal operating conditions, MTF consumed approximately one-third of the energy needed for DAF operation, mainly due to the fact that MTF requires less aeration. For future improvements in the AOM removal process, an energy-efficient pretreatment process could be realized for SWRO desalination facilities facing potential algal blooms. Unlabelled Image • Novel meshed tube filtration (MTF) was developed for algal bloom control in SWRO. • C. polykrikoides and T. suecica were tested as model marine microalgae species. • Coagulant dose and aeration rate were optimized for enhancing algal removal by MTF. • Turbidity and cell removal rates of MTF were comparable to dissolved air flotation. • MTF required only 33–39% of the energy needed for dissolved air flotation. [ABSTRACT FROM AUTHOR]

Seawater reverse osmosis (SWRO) is usually combined with brackish reverse osmosis (BWRO) to improve the water quality in seawater desalination; however, this configuration often results in high energy consumption. Consequently, membrane capacitive deionization (MCDI) has been suggested as a lower energy alternative technology, but cyclic operation within the cell (i.e., discontinuous operation of ad/desorption) is a main disadvantage. On the other hand, flow electrode capacitive deionization (FCDI) can be continuously operated by using a flow electrode. In this study, the feasibility of a SWRO-FCDI system was examined by using a suitable electrolyte in the flow electrode: seawater or SWRO concentrate. In addition, by employing a selective ion exchange membrane (IEM), the FCDI was able to selectively remove monovalent ions rather than divalent ions, unlike BWRO, thus producing a final product water containing divalent ions, which is more suitable for corrosion control in the subsequent pipe distribution systems. As a result, the remineralization process can be minimized. To test the SWRO-FCDI concept, actual SWRO permeate was first treated in a single mode with an electrolyte comprising real seawater in a flow electrode, and the feasibility of long-term operation was proven by batch-mode, which allowed the optimization of the FCDI active area. Unlabelled Image • The feasibility of a SWRO-FCDI system for low-energy desalination was examined. • Simulated seawater and SWRO concentrate were tested as electrolytes in FCDI. • FCDI removed divalent ions over monovalent ions with 30% higher efficiency. • Actual SWRO permeate was treated by FCDI using with a real seawater electrolyte. • In the batch mode, over 95% removal efficiency was achieved at a 1.3 kWh/m3. [ABSTRACT FROM AUTHOR]

In this study, the FO/crystallization/RO hybrid process was analyzed comprehensively, including experimentation, modeling, and energy and cost estimation, to examine and improve its feasibility to seawater desalination. A new operating strategy by heating the FO process to 45 °C was suggested, and a detailed process design was conducted. A comparative analysis with the conventional seawater reverse osmosis (SWRO) process was performed in terms of specific energy consumption (SEC) and specific water cost (SWC). The hybrid process can produce fresh water with SWC of 0.6964 $/m3, electrical SEC of 2.71 kWh/m3, and thermal SEC of 14.684 kWh/m3. Compared to the conventional SWRO process (SWC of 0.6890 $/m3 and electrical SEC of 2.674 kWh/m3), the hybrid process can produce water with comparable cost and energy consumption. An economic feasibility study that utilized the waste heat and the developed FO technology was also carried out to investigate future developments of the hybrid process. The SWC can be reduced to 0.6435 $/m3 with free waste heat energy. The permeate water quality of the hybrid process was about half that of the conventional SWRO process on molar basis. The results revealed that the FO/crystallization/RO hybrid process can be utilized as a competitive process for seawater desalination with high recovery and high water quality. Image 1 • New operation mode of FO/crystallization/RO hybrid process suggested. • Applicability of FO/crystallization/RO hybrid process experimentally confirmed. • This hybrid process confirmed as cost-competitive for seawater desalination. • Utilizing waste heat, water produced at 7% lower cost than that with SWRO. • Permeate water quality approximately half of the conventional SWRO on molar basis. [ABSTRACT FROM AUTHOR]