Treatment of Reverse Osmosis Concentrates

Membrane technologies especially reverse osmosis (RO) is constantly helping mankind for the purification of saline water to meet the skyrocketing water demand, thereby raising their environmental concern. This work focused on the use of Cobalt and Nickel nanoparticles for the treatment of RO concentrates. The studies revealed that both Cobalt and Nickel achieved TDS removal efficiencies of 76% and 66.3% for synthetic samples respectively. Batch studies on real effluents achieved maximum TDS removal efficiencies of 78.76% for Cobalt and 68.15% for Nickel i.e. pH 2, agitation time 160 minutes, dosage 0.2 g. A 1:1 mass combination of Cobalt and Nickel nanoparticles resulted in a TDS removal of 80.21%. Design of experiments and optimization by response surface methodology (RSM) were done using software (Design Expert 10). The optimized parameters were: for Cobalt nanoparticles (TDS removal efficiency: 76.45%, pH: 2, dosage: 0.25 g and agitation time: 200 minutes); for Nickel nanoparticles (TDS removal efficiency: 67.85%, pH: 2, dosage: 0.26g and agitation time: 210 minutes).