title: Separation of sodium chloride from the evaporated residue of the reverse osmosis reject generated in the leather industry--optimization by response surface methodology.
abstract: Reverse osmosis (RO) concentrate is being evaporated by solar/thermal evaporators to meet zero liquid discharge standards. The resulted evaporated residue (ER) is contaminated with both organic and inorganic mixture of salts. The generation of ER is exceedingly huge in the leather industry, which is being collected and stored under the shelter to avoid groundwater contamination by the leachate. In the present investigation, a novel process for the separation of sodium chloride from ER was developed, to reduce the environmental impact on RO concentrate discharge. The sodium chloride was selectively separated by the reactive precipitation method using hydrogen chloride gas. The selected process variables were optimized for maximum yield ofNaCl from the ER (optimum conditions were pH, 8.0; temperature, 35 degrees C; concentration of ER, 600 g/L and HCl purging time, 3 min). The recovered NaCl purity was verified using a cyclic voltagramm.
authors: R
authors: R
authors: Boopathy
authors: G
authors: G
authors: Sekaran
mesh_terms: D011232:Chemical Precipitation; D005740:Gases / Q000737:chemistry; D006851:Hydrochloric Acid / Q000737:chemistry; D007220:Industrial Waste; D015233:Models, Statistical; D012965:Sodium Chloride / Q000302:isolation & purification*; D013633:Tanning
chemical_list: D005740:Gases; D007220:Industrial Waste; D012965:Sodium Chloride; D006851:Hydrochloric Acid