Yes / Reverse osmosis system has been widely used for the separation of organic and non-organic pollutants present in wastewater. The main aim of this study is to develop a one dimensional steady state model based on the three-parameter Spiegler-Kedem methodology using the gPROMS software and validate it by assessing the performance of membrane rejection for the separation data of aqueous solutions of phenol under different concentrations and pressures. Considerations of the variance of pressure, flow rate, solute concentration, solvent and solute fluxes and mass transfer coefficient along the feed channel were included in the model. Furthermore, an optimization methodology for the gEST parameter estimation tool has been developed in the gPROMS and used with experimental data in order to estimate the best values of the separation membrane parameters and the friction parameter. The simulation results of this model have been corroborated by experimental data.

Yes / Reverse osmosis (RO) has found extensive applications in industry as an efficient separation process in comparison with thermal process. In this study, a one-dimensional distributed model based on a wastewater treatment spiral-wound RO system is developed to simulate the transport phenomena of solute and water through the membrane and describe the variation of operating parameters along the x-axis of membrane. The distributed model is tested against experimental data available in the literature derived from a chlorophenol rejection system implemented on a pilot-scale cross-flow RO filtration system with an individual spiral-wound membrane at different operating conditions. The proposed model is then used to carry out an optimisation study using a genetic algorithm (GA). The GA is developed to solve a formulated optimisation problem involving two objective functions of RO wastewater system performance. The model code is written in MATLAB, and the optimisation problem is solved using an optimisation platform written in C++. The objective function is to maximize the solute rejection at different cases of feed concentration and minimize the operating pressure to improve economic aspects. The operating feed flow rate, pressure and temperature are considered as decision variables. The optimisation problem is subjected to a number of upper and lower limits of decision variables, as recommended by the module’s manufacturer, and the constraint of the pressure loss along the membrane length to be within the allowable value. The algorithm developed has yielded a low optimisation execution time and resulted in improved unit performance based on a set of optimal operating conditions.

Yes / Reverse osmosis (RO) has long been recognised as an efficient separation method for treating and removing harmful pollutants, such as dimethylphenol in wastewater treatment. This research aims to study the effects of RO network configuration of three modules of a wastewater treatment system using a spiral-wound RO membrane for the removal of dimethylphenol from its aqueous solution at different feed concentrations. The methodologies used for this research are based on simulation and optimisation studies carried out using a new simplified model. This takes into account the solution-diffusion model and film theory to express the transport phenomena of both solvent and solute through the membrane and estimate the concentration polarization impact respectively. This model is validated by direct comparison with experimental data derived from the literature and which includes dimethylphenol rejection method performed on a small-scale commercial single spiral-wound RO membrane system at different operating conditions. The new model is finally implemented to identify the optimal module configuration and operating conditions that achieve higher rejection after testing the impact of RO configuration. The optimisation model has been formulated to maximize the rejection parameters under optimal operating conditions of inlet feed flow rate, pressure and temperature for a given set of inlet feed concentration. Also, the optimisation model has been subjected to a number of upper and lower limits of decision variables, which include the inlet pressure, flow rate and temperature. In addition, the model takes into account the pressure loss constraint along the membrane length commensurate with the manufacturer’s specifications. The research clearly shows that the parallel configuration yields optimal dimethylphenol rejection with lower pressure loss.

Yes / Reverse Osmosis (RO) membrane process has been commonly used for clarification and concentration of apple juice processes, due to significant advance in membrane technology, requirements for low energy and cost, and effective retention of aroma components. In this paper, a multi-stage RO industrial full-scale plant based on the MSCB 2521 RE99 spiral-wound membrane module has been used to simulate the process of concentrating apple juice and to identify an optimal multi-stage RO process for a specified apple juice product of high concentration measured in Brix. The optimisation problem is formulated as a Nonlinear Programming (NLP) problem with five different RO superstructures to maximise the apple juice concentration as well as the operating parameters such as feed pressure, flow rate and temperature are optimised. A simple lumped parameter model based on the solution-diffusion model and the contribution of all sugar species (sucrose, glucose, malic acid, fructose and sorbitol) to the osmotic pressure is assumed to represent the process. The study revealed that the multi-stage series RO process can optimise the product concentration of apple juice better than other configurations. It has been concluded that the series configuration of twelve elements of 1.03 m2 area improves the product apple juice concentration by about 142% compared to one element. Furthermore, the feed pressure and flow rate were found to have a significant impact on the concentration of the apple juice.

Yes / The implementation of Reverse Osmosis (RO) technology is noticeably increased to produce freshwater from brackish and seawater resources. In this work, performance analysis of a multistage multi pass medium-sized spiral wound brackish water RO (BWRO) desalination plant (1200 m³/day) of Arab Potash Company (APC) located in Jordan is evaluated using modelling and simulation. For this purpose, a mathematical model for the spiral wound RO process based on the principles of solution diffusion model is developed. The model is then used to simulate the operating conditions of low-salinity brackish water RO (BWRO) desalination plant. The results obtained are then compared against the real industrial data of BWRO desalination plant of APC which shows a high-level of consistency. Finally, the model is used to analysis the impact of the operating parameters such as salinity, pressure, temperature, and flow rate on the plant performance. The sensitivity analysis confirms that both feed flow rate and operating pressure as the critical parameters that positively affect the product salinity.

No / An experimental study of coupling compensation for AOA estimation using compact low profile antenna arrays with element separations of a quarter wavelength has been conducted. Two circular arrays of low profile miniaturised logarithmic spiral antennas deployed on a circular metal plate were used for data acquisition. Using the MUSIC direction-finding algorithm, the AOA estimation errors in receiving mode were observed before and after compensation: the errors were significantly decreased by coupling compensation.

Studiens syfte är att undersöka potentialen och effektiviteten av spiralljuddämpare jämfört med standardljuddämpare för kompressorer i Värme och luftkonditionerings system i bilar. Den ökande efterfrågan på kompakta och effektiva lösningar inom fordonsindustrin, ledde till utforskning av alternativa tekniker som kan bidra till att förbättra bilens prestanda och passagerarkomfort. En ljuddämpartyp som vore intressant att nyttja för denna tillämpning är spiralformade ljuddämpare. Dessa enheter är mer kompakta jämfört med standardljuddämpare, vilket gör dem till ett attraktivt alternativ för biltillverkare som strävar efter att optimera utrymmesanvändningen inom fordonet. Dessutom, tidigare studier visade att spiralformade ljuddämpare kan erbjuda effektiv akustisk dämpning, vilket kan bidra till en mer bekväm och tyst körupplevelse. I denna studie kommer vi att genomföra en omfattande litteraturöversikt över befintliga modeller och prestanda för spiralljuddämpare. Vi kommer sedan att genomföra en jämförande analys mellan spiralformade ljuddämpare och standardljuddämpare en s.k. expansionskammare. Resultaten från denna analys kommer att presenteras och diskuteras i detalj, med syftet att dra slutsatser om effektiviteten av spiralformade ljuddämpare och deras potential för framtida tillämpningar inom fordonsindustrin. Denna studie kommer att genomföras i samarbete med Volvo Cars i Göteborg.

Yes / Reverse osmosis (RO) is becoming one of the most promising technologies used in wastewater treatment because it offers high rate of contaminant rejection and lower energy consumption in comparison with other thermal treatment processes. Earlier research by the same authors in respect of a distributed one-dimensional mathematical model for a single spiral-wound RO membrane module based on the solution-diffusion model has been used in this paper to simulate the rejection of NDMA (N-nitrosodimethylamine) from wastewater in a series of seven RO elements full-scale treatment plant. Firstly, the applicability of this model has been evaluated using a simulation study and the results have been compared against experimental data gathered from the literature for a given plant. Secondly, further simulation and analysis studies are carried out to assess the performance of the plant for NDMA rejection and recovery rate under different operating conditions of feed pressure, flow rate, and concentration. For the studied RO configuration, it is concluded that a maximum of 55.1% NDMA rejection can be achieved, which confirms the remaining issue of lower NDMA rejection.

Yes / N-nitrosamine in wastewater treatment processes can contribute to several public health impacts including human carcinogens even at very low concentration. In this work, spiral-wound reverse osmosis (SWRO) process is used to remove N-nitrosamine compounds from wastewater. Effects of operating parameters of the SWRO process on the removal of N-nitrosamine, total water recovery, and specific energy consumption for a SWRO configurations are evaluated via simulation and optimisation. For this purpose, the one-dimensional distributed model developed earlier by the authors is modified by including different mass transfer coefficient correlation, temperature dependent water and solute permeability correlations and energy equations. The model is first validated by estimating a new set of model parameters using eight set of experimental data from the literature and is then used to simulate the process with and without energy recovery device to facilitate deeper insight of the effect of operating conditions on the process performance. The model is then embedded within an optimisation framework and optimisation problems to maximise N-nitrosamine rejections and to minimise specific energy consumption are formulated and solved while the operating conditions are optimized simultaneously.

Yes / Reverse Osmosis (RO) processes are readily used for removing pollutants, such as dimethylphenol from wastewater. A number of operating parameters must be controlled within the process constraints to achieve an efficient removal of such pollutants. Understanding the process dynamics is absolutely essential and is a pre-step for designing any effective controllers for any process. In this work, a detailed distributed two-dimensional dynamic (x and y dimensions and time) model for a spiral-wound RO process is developed extending the 2-D steady state model of the authors published earlier. The model is used to capture the dynamics of the RO process for the removal of dimethylphenol from wastewater. The performance of the 2-D model is compared with that obtained using 1-D dynamic model before the model is being used to investigate the performance of the RO process for a range of operating conditions.