scholarly journals Comparison of Nanofiltration with Reverse Osmosis in Reclaiming Tertiary Treated Municipal Wastewater for Irrigation Purposes

Membranes ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 32
Author(s):  
MhdAmmar Hafiz ◽  
Alaa H. Hawari ◽  
Radwan Alfahel ◽  
Mohammad K. Hassan ◽  
Ali Altaee
Keyword(s):  
Energy Consumption ◽  
Reverse Osmosis ◽  
Specific Energy ◽  
Recovery Rate ◽  
Municipal Wastewater ◽  
Water Flux ◽  
Applied Pressure ◽  
Specific Energy Consumption ◽  
Water Recovery ◽  
Food And Agriculture

This study compares the performance of nanofiltration (NF) and reverse osmosis (RO) for the reclamation of ultrafiltered municipal wastewater for irrigation of food crops. RO and NF technologies were evaluated at different applied pressures; the performance of each technology was evaluated in terms of water flux, recovery rate, specific energy consumption and quality of permeate. It was found that the permeate from the reverse osmosis (RO) process complied with Food and Agriculture Organization (FAO) standards at pressures applied between 10 and 18 bar. At an applied pressure of 20 bar, the permeate quality did not comply with irrigation water standards in terms of chloride, sodium and calcium concentration. It was found that nanofiltration process was not suitable for the reclamation of wastewater as the concentration of chloride, sodium and calcium exceeded the allowable limits at all applied pressures. In the reverse osmosis process, the highest recovery rate was 36%, which was achieved at a pressure of 16 bar. The specific energy consumption at this applied pressure was 0.56 kWh/m3. The lowest specific energy of 0.46 kWh/m3 was achieved at an applied pressure of 12 bar with a water recovery rate of 32.7%.

scholarly journals Batch Reverse Osmosis Desalination Modeling under a Time-Dependent Pressure Profile

Membranes ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 173
Author(s):  
Abdeljalil Chougradi ◽  
François Zaviska ◽  
Ahmed Abed ◽  
Jérôme Harmand ◽  
Jamal-Eddine Jellal ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Reverse Osmosis ◽  
Specific Energy ◽  
Energy Demand ◽  
Specific Energy Consumption ◽  
Pressure Profile ◽  
Recovery Ratio ◽  
Feed Concentration ◽  
Energetic Performance ◽  
Feed Volume

As world demand for clean water increases, reverse osmosis (RO) desalination has emerged as an attractive solution. Continuous RO is the most used desalination technology today. However, a new generation of configurations, working in unsteady-state feed concentration and pressure, have gained more attention recently, including the batch RO process. Our work presents a mathematical modeling for batch RO that offers the possibility of monitoring all variables of the process, including specific energy consumption, as a function of time and the recovery ratio. Validation is achieved by comparison with data from the experimental set-up and an existing model in the literature. Energetic comparison with continuous RO processes confirms that batch RO can be more energy efficient than can continuous RO, especially at a higher recovery ratio. It used, at recovery, 31% less energy for seawater and 19% less energy for brackish water. Modeling also proves that the batch RO process does not have to function under constant flux to deliver good energetic performance. In fact, under a linear pressure profile, batch RO can still deliver better energetic performance than can a continuous configuration. The parameters analysis shows that salinity, pump and energy recovery devices efficiencies are directly linked to the energy demand. While increasing feed volume has a limited effect after a certain volume due to dilution, it also shows, interestingly, a recovery ratio interval in which feed volume does not affect specific energy consumption.

scholarly journals Energy efficiency of staged reverse osmosis (RO) and closed-circuit reverse osmosis (CCRO) desalination: a model-based comparison

2020 ◽  
Vol 20 (8) ◽  
pp. 3096-3106
Author(s):  
Simeng Li ◽  
Karla Duran ◽  
Saied Delagah ◽  
Joe Mouawad ◽  
Xudong Jia ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Reverse Osmosis ◽  
Specific Energy ◽  
Numerical Models ◽  
Specific Energy Consumption ◽  
Closed Circuit ◽  
Two Stage ◽  
One Stage ◽  
Multi Stage

Abstract Reverse osmosis (RO) technologies have been widely implemented around the world to address the rising severity of freshwater scarcity. As desalination capacity increases, reducing the energy consumption of the RO process per permeate volume (i.e., specific energy consumption) is of particular importance. In this study, numerical models are used to characterize and compare the energy efficiency of one-stage continuous RO, multi-stage continuous RO, and closed-circuit RO (CCRO) processes. The simulated results across a broad range of feed salinity (5,000–50,000 ppm, i.e., 5–50 g kg−1) and recovery (40%–95%) demonstrate that, compared with the most common one-stage continuous RO, two-stage and three-stage continuous RO can reduce the specific energy consumption by up to 40.9% and 53.6%, respectively, while one-stage and two-stage CCRO can lead to 45.0% and 67.5% reduction, respectively. The differences in energy efficiencies of various RO configurations are more salient when desalinating high-salinity feed at a high recovery ratio. From the standpoints of energy saving and capital cost, the simulated results indicate that multi-stage CCRO is an optimal desalination process with great potential for practical implementation.

Emerging investigator series: membrane distillation and high salinity: analysis and implications

2020 ◽  
Vol 6 (6) ◽  
pp. 1538-1552 ◽  
Author(s):  
Mukta Hardikar ◽  
Itzel Marquez ◽  
Andrea Achilli
Keyword(s):  
Energy Consumption ◽  
Temperature Difference ◽  
Specific Energy ◽  
Energy Efficient ◽  
High Salinity ◽  
Water Flux ◽  
Specific Energy Consumption ◽  
Membrane Distillation

In energy efficient membrane distillation, the low transmembrane temperature difference exacerbates salinity's effect on water flux and specific energy consumption.

scholarly journals Electrooxidation Using Nb/BDD as Post-Treatment of a Reverse Osmosis Concentrate in the Petrochemical Industry

2019 ◽  
Vol 16 (5) ◽  
pp. 816 ◽  
Author(s):  
Salatiel Wohlmuth da Silva ◽  
Carla Venzke ◽  
Júlia Bitencourt Welter ◽  
Daniela Schneider ◽  
Jane Zoppas Ferreira ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Reverse Osmosis ◽  
Specific Energy ◽  
Energy Requirement ◽  
Specific Energy Consumption ◽  
Oxygen Demand ◽  
Inorganic Ions ◽  
Oxidation Time ◽  
Kinetic Regime ◽  
Boron Doped Diamond

This work evaluated the performance of an electrochemical oxidation process (EOP), using boron-doped diamond on niobium substrate (Nb/BDD), for the treatment of a reverse osmosis concentrate (ROC) produced from a petrochemical wastewater. The effects of applied current density (5, 10, or 20 mA·cm−2) and oxidation time (0 to 5 h) were evaluated following changes in chemical oxygen demand (COD) and total organic carbon (TOC). Current efficiency and specific energy consumption were also evaluated. Besides, the organic byproducts generated by EOP were analyzed by gas chromatography coupled to mass spectrometry (GC–MS). The results show that current densities and oxidation time lead to a COD and TOC reduction. For the 20 mA·cm−2, changes in the kinetic regime were found at 3 h and associated to the oxidation of inorganic ions by chlorinated species. After 3 h, the oxidants act in the organic oxidation, leading to a TOC removal of 71%. Although, due to the evolution of parallel reactions (O2, H2O2, and O3), the specific energy consumption also increased, the resulting consumption value of 66.5 kW·h·kg−1 of COD is considered a low energy requirement representing lower treatment costs. These results encourage the applicability of EOP equipped with Nb/BDD as a treatment process for the ROC.

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