Bioadsorption and membrane technology for reduction and recovery of chromium from tannery industry wastewater

• Removal of chromium by bioadsorption and recovered by reveres osmosis.
• Effect of pH, contact time and concentration on chromium removal efficiency.
• Effect of flow rate, pressure and feed concentration on recovery of chromium.
• Eucalyptus shows 99% of adsorption at pH 4, contact time 240 min and mass loading 3.5 g/l.
• Reverse osmosis membrane shows 99.9% of recovery at optimum pH 6.8, inlet flow rate 0.72 m3/h, working pressure 40 bars.

Chromium plays dual role for industry and environment, one side it is important to improve the quality and second side it damages the life. To come out from this problem substitution will be required to maintain both the faces. Keeping this point it was planned to carry out the experiment for reduction and then recovery of chromium from tannery wastewater. For the reduction purpose low cost and waste are used as adsorbent like saw dust, coffee husk and eucalyptus bark was used as adsorbent material. Among all adsorbents eucalyptus shows 99% of adsorption at pH 4, contact time 240 min and mass loading 3.5 g/l. Recovery of chromium was carried out with three different types of membrane among them AFC 99 reverse osmosis membrane shows 99.9% of recovery at optimum pH 6.8, inlet flow rate 0.72m3/h, working pressure 40 bars.