Reverse Osmosis Process Control

This study explores the application and robustness of an adaptive optimal control (AOC) strategy to optimize operation membrane filtration systems. The proposed is based on a constant flux model where fouling primarily due cake layer formation. algorithm dynamically finds ratio between (F) backwash (BW) time in response system disturbances, thereby adapting operational state order its performance terms energy consumption. was successfully applied both microfiltration (MF) ultrafiltration (UF) systems quantitatively demonstrated effectiveness reducing consumption controlling fouling. It proved robust against uncertainties real-time adaptability even under varying realistic disturbance conditions. implementation this facilitated adaptation filtration/backwash (F/BW) dynamic disturbances. result underlines that behavior predominantly driven by fluctuations mixed liquor suspended solids (MLSSs). Compared conventional fixed-time modes, AOC led significant savings, ranging from 7% 30%, lifespan extension, mainly through more efficient permeate pump usage.

Source

Reverse osmosis water treatment system and method that uses a two-stage filtration process to improve water quality. In the first stage, a high-flux reverse osmosis membrane removes impurities from the feed water. In the second stage, a lower-flux reverse osmosis membrane further filters the permeate from the first stage. The key difference is that the second-stage membrane has a lower flux per pressure unit than the first-stage membrane. This allows lowering the water quality degradation that can occur when using a membrane with lower rejection. By using a second-stage membrane with lower flux, the water quality can be improved compared to using a single high-flux membrane.

Source

Membrane fouling remains a persistent challenge in reverse osmosis (RO) systems. Devising effective strategies to mitigate membrane has become crucial for sustainable water treatment. Here, we propose titanium-based pre-coagulation strategy RO mitigation through regulation of the microbial habitat feed. The performance Ti(SO4)2 desulfurization wastewater and subsequent mechanism were systematically investigated. Our findings revealed that Ti induced an acidized environment, maintained balance between organic inorganic depositions, fostered beneficial community resisted rapid fouling. 20 day operations different scenarios (Ti, Al, Ctrl) showed group membranes highest normalized flux at 57.15%, outperforming Ctrl Al groups by 7.92% 15.16%, respectively. Microbial analyses, including taxonomic profiling metagenomic analysis, demonstrated Ti-based reduced dominance extracellular polymeric substance (EPS)-secreting genera, such as Sphingopyxis, while promoting Terrimonas Paenarthrobacter, with acid-tolerance traits EPS production. This shift mitigated biofouling enhancing limiting biofilm... Read More

Source

This study investigates the potential for energy reduction in a full-scale Seawater Reverse Osmosis (SWRO) desalination plant through hybrid integration with Pressure Retarded (PRO). A pilot test using 60 m 2 PRO membrane kit helped determine key operating parameters, including draw solution (DS) pressure and resulting dilution fluxes. Subsequently, analysis was conducted 650 of area. The demonstrated up to 12.56% specific consumption under optimized conditions. Energy savings were found correlate positively lower feed pressures, higher brine availability, optimal rates, while being negatively impacted by losses high DS-to-FS flow ratios. confirms viability PRO-SWRO hybridization as method enhancing efficiency, highlights areas further optimization design hydraulic configuration.

Source

A system for efficiently and cost effectively removing impurities from fluids like water, oilfield wastewater, and produced water. The system uses a series of stages with devices like filtration, coagulation, reverse osmosis, thermal distillation, and recapture. The stages are arranged in a coordinated manner to progressively purify the fluid, remove specific components, and recapture energy. This allows efficient, customizable purification and recycling of wastewater while minimizing freshwater use. The stages can be containerized for portable, modular systems.

Source

Concentrating saline water is essential for zero liquid discharge (ZLD) of wastewater. However, prevailing membrane-based technologies, such as reverse osmosis (RO) and electrodialysis (ED), can hardly handle high concentration differences (C) in a single stage, where multi-stage operation needed, which increases the operational difficulties energy input. membrane capacitive deionization (MCDI) theoretically applicable to C. This study explored feasibility employing an MCDI brine concentrating proposed several regulating measures on electrode's porosity, electrical quantity charging-discharging, desorption conditions. Based determination salt fluxes, these were confirmed mitigate transfer across membrane, thereby facilitating transportation concentrating. To address mass imbalance between adsorbed desorbed, novel pre-charge strategy was designed, enabled successful continuous over 50 cycles. A difference 161 g/L NaCl achieved per highest reported result among RO, ED, studies. The rate 38.4 g/(m2h) with comparative consumption at RO ED. demonstrated that optional technology futu... Read More

Source

Reverse osmosis (RO) desalination technology offers a promising solution for mitigating water scarcity. However, one of the major challenges faced by RO membranes is biofouling, which significantly increases costs. Traditional simulation models often overlook environmental variability and do not incorporate effects membrane-surface modifications. This paper develops bacterial growth model prediction seawater performance, applicable to commercial membranes, can be either uncoated or coated with iron nanoparticles (FeNPs nZVI). FeNPs were selected due their known antimicrobial properties potential mitigate biofilm formation. The native bacterium Bacillus halotolerans MCC1 was used as biofouling bacterium. Growth kinetics determined at different temperatures (from 26 50 C) pH values 4 10) obtain parameters. Microbial on modeled using Monod equation. performance evaluated in terms hydraulic resistance permeate flux under clean biofouled conditions. validated data obtained laboratory scale. Bacteria grew faster 42 C 10. had more significant effect than temperature rate. FeNP-coated ex... Read More

Source

Integrated membrane filtration system for brine management in desalination plants to mitigate environmental impacts of high salinity discharge. The system uses a sequence of nanofiltration (NF) stages followed by reverse osmosis (RO) stages. The NF stages perform diafiltration to dilute and separate ions. The NF permeate feeds the RO stages. This allows optimizing ion fractionation and brine concentration while avoiding high salinity discharge.

Source

Optimizing reverse osmosis water desalination systems using machine learning to reduce operating costs and improve performance by predicting when to clean the membranes. The system measures parameters like feed pressure, flow, salinity, temperature, etc. and uses a trained ML model to determine fouling levels and optimize flow rates through the stages. This allows reducing energy use while maintaining permeate production. By predicting when fouling will inflect and decline, cleaning can be timed to minimize energy vs waiting for a 10% flux drop. The ML model also balances flow across stages for energy savings.

Source

ABSTRACT This article presents a model-predictive controller (MPC) for the maximization of energy efficiency closed-circuit desalination reverse osmosis (CCRO) system. CCRO is process producing drinking water that based on cyclic operation with following two phases: (a) filtration and (b) drain. In this article, we test model predictive control optimal process. The most important features our approach are as follows: selection structure enables reliable forecasts phase (up to 3 h), an on-line calibration strategy ensures forecast reliability, (c) satisfaction equipment safety operational constraints selected setpoints. We challenge through deliberate introduction changes in unmeasured feed concentration applied constraints. Our results indicate frequent parameter updates critical maintain reliability MPC purposes. addition, illustrate identifiability not guaranteed variation flow rates necessary even though never operates steady state. Finally, can compute rate setpoints maximize while satisfying applicable

Source

Reverse osmosis system with optimized energy consumption for water treatment applications like desalination or wastewater reclamation. The system uses a chain of membrane units connected in sequence. Each membrane unit has an inlet, outlet, and concentrate outlet. The concentrate outlet of a unit feeds into the inlet of the next unit. The final unit's concentrate outlet connects to a hydraulic motor. This motor is connected to an electric generator. The generator can drive a pump upstream of a membrane unit to boost feed pressure. This recycles concentrate energy to drive the system. It eliminates wasteful high-pressure feed pumps. The motor can be variable frequency to adapt to changing conditions. Sensors on the axial piston machines monitor flow and pressure.

Source

Water treatment method and apparatus to prevent biofouling of reverse osmosis (RO) membranes without harming the membranes. The method involves intermittently adding biocides to the water feed to the RO membrane. The biocide dose and frequency are adjusted based on membrane fouling levels. This prevents excessive biocide concentrations that can harm the membrane. The biocide addition is tuned to keep oxidation potential below a threshold without exceeding it. This prevents biocide-induced membrane fouling while still providing adequate biocide dosing to prevent organic growth.

Source

Access to clean and potable water is a growing global concern, particularly in coastal arid regions where freshwater sources are scarce. Traditional desalination tech- niques, such as thermal distillation conventional reverse osmosis, rely heavily on fossil fuel-based energy sources, leading high operational costs significant environmental impacts, including greenhouse gas emissions. Additionally, these systems often require complex infrastructure, making them inaccessible remote off-grid communities. To address challenges, this research presents novel solar-powered machine that integrates Reverse Osmosis (RO) Ultraviolet (UV) purification technologies. The proposed system harnesses solar power high-pressure pumps, eliminating dependency non-renewable sources. RO unit effectively removes dissolved salts contaminants, while the UV stage ensures microbial disinfection, delivering high-quality drinking water. By utilizing renewable energy, significantly reduces minimizes carbon emissions, mak- ing it an environmentally sustainable economically viable solution. impact of extends enhancin... Read More

Source

Osmotic membrane separation system with feed and draw recirculation loops in each module to improve efficiency and prevent fouling. The system has a series of osmosis modules where feed and draw solutions are circulated co-currently through each module. Feed recirculation loops connect feed inlet to outlet of each module. Draw recirculation loops connect draw inlet to outlet. This allows controlled flow rates, solute concentrations, and hydrostatic pressures in each loop. The bulk feed and draw streams flow counter-currently through the system as a whole. The recirculation loops prevent boundary layer buildup and fouling. They also allow mixing of partially concentrated streams to reduce driving force and enhance membrane efficiency.

Source

Pure water production system with optimized water quality and energy efficiency when flow rate varies. The system has sensors to detect effective membrane pressure in the reverse osmosis section. Based on the sensor readings, it adjusts the number of parallel membranes treating the water. This allows maintaining stable membrane performance and water quality as flow rate changes, preventing deterioration. By dynamically matching membrane capacity to flow, it can save pump energy compared to fixed membrane systems.

Source

Automatic flow control for membrane water purification systems to optimize water production and membrane life while reducing waste. The method involves using a controller to dynamically adjust the diaphragm valve opening based on parameters like membrane performance, pump pressure, and water quality. This ensures the right balance of purified water flow and wastewater flow without manual intervention. The controller calculates an optimal ratio of wastewater to purified water to prevent excessive waste or membrane fouling. It also monitors factors like membrane temperature and pressure to detect fouling conditions and flush the membrane.

Source

A support system for optimizing water treatment processes using membrane filtration. The system uses machine learning to analyze water quality, filtration conditions, and membrane performance data to determine optimal permeation flux, cleaning frequencies, and cleaning conditions for the membrane filtration device. This provides recommendations to the water treatment operator on how to optimize their processes for better water treatment efficiency and membrane longevity.

Source

A system to adjust the flow rate of water coming out of a water purifier. It uses sensors to measure the inlet water temperature, pressure, and flow, and then adjusts the output pressure and/or flow of the water pump in the purifier. This allows correcting the water output to meet requirements for membranes like reverse osmosis. It solves the issue that existing water purifiers cannot adjust pump performance to match membrane needs. The system can also have buttons to change flow rates.

Source

Operating a water filtration system using a membrane module to identify clogged areas and clean them efficiently. The method involves monitoring pressure drops during filtration, backwashing, and water discharge. By comparing changes in these resistance values, it can determine if clogging is worse in certain areas. If so, it performs targeted cleaning like air washing, longer discharge time, or pressurized discharge. The idea is to proactively identify and address localized fouling without wasting water by blindly cleaning the whole module.

Source

Monitoring and optimizing the performance of membrane filters in filtration systems by continuously measuring the flow rate of permeate fluid and comparing it to a predefined flux rate. If the measured flux falls below the threshold, the system switches to a flux tolerant mode that allows higher fouling and lower filtration efficiency. This prevents unnecessary filter replacements when flux degradation is minor. The system also determines a normalized water permeability value based on the flux measurements to further assess filter health.

Source