چكيده به لاتين
Recently, geopolymeric membranes have attracted attention due to their ease of preparation, no high-temperature calcination, and inexpensive precursors. This thesis aims to develop a new method for preparing a geopolymer membrane to remove turbidity from textile industrial wastewater. Geopolymeric membranes were fabricated using metakaolin activated with a blend of sodium hydroxide and silica fume The influence of preparation factors, i.e., silica fume content (0 to 25% wt. of metakaolin substitution), Na2O/Al2O3 molar ratio in the range of 0.8 to 1.2, and curing temperature (60, 70, and 80 °C), were investigated on the product compressive strength and pure water permeability. Five membranes were chosen with a compressive strength above 20 MPa and pure water permeability above 50 L/m2 h bar. The membranes were characterized using X-ray diffraction, Scanning electron microscopy, Fourier transform infrared spectroscopy, mercury intrusion porosimetry, energy dispersion spectroscopy, and compressive strength measurements. The result of these five membranes showed, a membrane containing 10 wt.% of silica fume, a Na2O/Al2O3 molar ratio of 1, and a curing temperature of 60 °C provided the greatest wastewater permeability and turbidity reductions were 75 L/m2 h bar and 95.5% respectively under 1.2 bar pressure, 25 °C feed temperature, and 1 L/min feed flow rate during microfiltration of the industrial textile effluent. Design of the experiments (full factorial and response surface methodology) was used to identify the most effective parameters and optimization of membranes separation performance. The optimum membrane showed the maximum normalized permeability and turbidity reduction of 0.57 and 97.98%, respectively, at 1.2 bar pressure, 59.9 °C feed temperature, and 1.73 L/min feed flow rate. The fouling study of the membrane revealed the order fouling resistances are cake layer>reversible> irreversible. Four cyclic filtrations of the real textile wastewater recovered more than 97.4% flux and 99.5% turbidity reduction after successive filtration and regeneration of the optimum membrane. Also, the membrane containing 15 wt.% of silica fume, Na2O/Al2O3molar ratio of 1, and the curing temperature of 60 oC (15 S + 1 N + 60 T) was used forthe removal of methylene blue dye by oil emulsion method. The results of the box- Bencken design showed that the optimal membrane has a maximum permeability of 70.28 l/m2.h.bar and a dye removal rate of 98.45%, at a feed flow rate of 1.5 l/min, SDS concentration of 5.33% in methylene concentration of 100 ppm.