Application of response surface methodology for modeling and optimization of membrane distillation desalination process

Central composite design (CCD) was applied in this work to analyze the performance of poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) flat sheet membrane in the seawater desalination using direct contact membrane distillation (DCMD) process. It is the most popular in response surface method (RSM). Development on Quadratic Regression model for membrane performance as a function of the operating conditions was studied. The ranges for each operating condition were selected as follows: feed temperature (Tf): 48–58 °C, feed flow rate (Qf): 80–180 mL/min, permeate temperature (Tp):17–22 °C and permeate flow rate (Qp): 80–180 mL/min. The model R-squared of 0.9759 (adjusted to degree-of-freedom), Lack-of-fit test (p = 0.4764), predicted residual error sum of squared (PRESS) statistic of 10.3 suggest that the model is adequate to correlate the impact of operating conditions on permeates. ANOVA analysis showed that factors as feed flow rate, feed temperature, and permeate temperature have a valuable impact (p ≤ 0.05) on the response variable. Additionally, the interaction among feed temperature-feed flow rate, feed flow rate-permeate flow rate, and the quadratic impact of feed temperature, permeate temperature, and permeate flow rate have shown an important impact (p ≤ 0.05) on the permeate flux. Optimization of operating conditions to make the permeate flux and salt rejection high as possible was determined according to desirability function approach. A desirability of 0.969 was achieved at a feed temperature of 58 °C, feed flow rate of 180 mL/min, permeate temperature of 18.8 °C, and permeate flow rate of 145.3 mL/min in which a permeate flux of 12.56 kg/m2h and a salt rejection of 99.97% was obtained.

Application of PVDF membranes in desalination and comparison of the VMD and DCMD processes

Dynamic modeling of direct contact membrane distillation processes

Novel Janus composite hollow fiber membrane-based direct contact membrane distillation (DCMD) process for produced water desalination

Minerals recovery from a rare earth extraction wastewater by a combined chemical precipitation and membrane distillation process

Treatment of olive mill wastewater by membrane distillation using polytetrafluoroethylene membranes

Preparation of High Concentration Polyaluminum Chloride with High Al c Content by Membrane Distillation

Effects of thermal efficiency in DCMD and the preparation of membranes with low thermal conductivity

This paper examines the performance of a Direct Contact Membrane Distillation (DCMD) system experimentally and theoretically. The system uses a super hydrophobic electrospun nanofiber membrane to desalinate water. Investigations were carried out into how the feed concentration, feed flow rate, and feed temperature affected permeate flux. as system operating parameters to aid in comprehending the factors impacting the DCMD process. The application of DOE and Taguchi methods achieved statistical optimization of the DCMD process's performance. In addition, the study of mass and heat transport in DCMD was described by a theoretical model. While the feed concentration (0- 210 g/L) significantly affected flux, the feed's temperature (35-55 °C) and flow rate (0.2-0.6 L/min) mostly dominated the impact on system performance. The created model numerically solved the DCMD process using MATLAB software, describing it as a system of nonlinear equations. Various operating conditions were used to investigate the efficiency of the superhydrophobic electrospun nanofiber membrane in treating 210 g/L NaCl salt water. Changing the feed temperature and concentration affected the hypothetically suggested path across the membrane, according to the simulation results presented in this paper. Excellent agreement was observed between the experiment results and the constructed model's predicted results. Every instance maintained a high salt rejection rate (over 99.9%). The DCMD produced a gain output ratio (GOR) of 0.87 and a temperature polarization coefficient of 0.78 to 0.91. The system achieved a maximum thermal efficiency of 73.5%. The optimal parameters, which are 70 g/L, 0.6 L/min, and 55°C.

Potable water recovery from As, U, and F contaminated ground waters by direct contact membrane distillation process

Ammonia recovery via direct contact membrane distillation: Modeling and performance optimization

Effects of anti-scaling and cleaning chemicals on membrane scale in direct contact membrane distillation process for RO brine concentrate

Styrene-acrylonitrile (SAN) nanofibrous membranes with unique properties for desalination by direct contact membrane distillation (DCMD) process

The effect of hydrodynamic conditions (feed and permeate flow rates) and the action of six different types of antiscalants on desalination of seawater from the Gulf of Mexico by direct contact membrane distillation (DCMD) was studied. The effect of feed temperature during the DCMD process was also evaluated on performance of two microfiltration membranes (0.5 µm) having different thickness (300 and 250 µm). Results showed more than 100 % increments on water vapor flux by raising feed temperature from 50 to 70 oC and feed flow rates up to 7 L·min-1. No significant effect on process performance was determined by raising permeate flow rates in the range tested. Choosing the type and concentration of antiscalants is critical during seawater desalination by DCMD. Performance of this process increased by up to 49.2 % during desalination of real seawater by adding the KMRO S-516 antiscalant designed to disperse iron, silica and calcium carbonate salts. During DCMD no important water vapor flux decay and no increase on conductivity of the distillate was observed by antiscalants' dosage. In addition, scanning electron microscopy (SEM) from the membrane surface after DCMD desalination of seawater treated with the KMRO S-516 antiscalant confirmed the absence of scaling.

TiO2-FTCS modified superhydrophobic PVDF electrospun nanofibrous membrane for desalination by direct contact membrane distillation