Technical information

1. Nano-structured MnO2 based adsorbent that is capable of extracting cadmium from ppm-level aqueous solutions polluted with cadmium. The precipitation pH of cadmium in water is over pH10. However, the nano-structured MnO2 based adsorbent removes cadmium at pH 7.
   

1. Fig. 1 shows the rate of Cd adsorption from test water. The decrease of concentration of Cd is faster than that of a commercial MnO2 powdered adsorbent. Fig. 2 displays the effect of Cd concentration on the yield of Cd adsorption under pH 6.5- 7.
   

           

    Fig. 1 Rate of Cd adsorption                  Fig. 2 Effect of Cd concentration on yield

1. The adsorbed Cd can be recovered in 20 mL of acidic aqueous solution and enriched the concentration to 1000 ppm (Fig. 3). After the desorption of Cd, the adsorbent can be reused with the original efficiency.
   

1. Fig. 4 shows the decrease of Cd concentration in an actual mining effluent (1 L) containing Cd with 0.11mg/L at pH6.9. The concentration of Cd decreased to below 0.05mg/L by adding 1g of the nano-structured MnO2 based adsorbent.
   

Fig. 3 Enrichment of Cd eluted           Fig. 4 Decrease of Cd in an actual mining effluent