ANNOUNCEMENTS
The pulp and paper sector is one of highly polluting sectors in India consuming 905.8 million m³ of water and discharging 695.7 million m³ of wastewater annually. Forward osmosis (FO) works on no hydraulic pressure and energy efficient and is being studied exclusively for the treatment of municipal as well as industrial wastewater.
In the present study, cellulose triacetate (CTA) membranes have been used to concentrate lignin feed solution using different concentrations of Sodium Chloride (NaCl) (0.5M to 3M) as draw solution. After optimizing different concentration of DS at 1L/min and for 3 hours, 1.5M and 2M concentration appears to be best in terms of best water recovery obtained for continuing in long term study for 24 hours.
Water flux obtained is almost same in 1.5M and 2M DS i.e. 6.6 L/m²h and 7.2 L/m²h. Water recovery is 68.8% and 82.6% for the same. According to critical flux determination 1.5M DS concentration would be draw solution to carry out FO experiment for real wastewater (chlorinated and end of pipe types collected from pulp and paper mill) as water flux for lignin and DI water overlaps each other. 5.4 L/m²h and 6 L/m²h are the water flux obtained for CD and EOP type with 61.3 and 69.8% water recovery respectively.
Key words: Forward osmosis, lignin, cellulose triacetate, chlorinated, end of pipe.
