Effect of Artemia franciscana on the removal of nickel by bioaccumulation.

The present study evaluates the feasibility of using Artemia franciscana in reducing the Ni concentration of synthetic wastewater by the process of bioaccumulation. Metallothionein protein plays a key role in the uptake of nickel by Artemia. Artemia (Brine shrimp) was exposed to an initial nickel concentration of 40 mg/L. Gradual decrease of nickel was observed from 40 mg/L to 5 mg/L with a removal efficiency of 87.5%. The number of organisms were varied to determine the number for the maximum removal efficiency. Metallothionein protein in Artemia was estimated by the silver saturation method. The physical parameters such as pH were maintained in an alkaline condition of 9-10, temperature was maintained at room temperature and salinity at 30-35‰. These were found to be the optimal conditions for the survival and reduction of nickel by Artemia.

Recovery and reuse of Ni(II) from rinsewater of electroplating industries.

Discharge of nickel compounds, which may occur in both liquid and solid phases, can cause severe environmental problems. In this work, 'point of source' treatment strategy is followed and reduced the nickel content of rinsewater to about less than 1 mg L(-1) by ion-exchange method using a packed column involving batch recirculation mode of operation and to recovered Ni(II) content by desorption. The treated water could be recycled for rinsing operation. The nickel from resin is first precipitated as nickel hydroxide to synthesize positive active material and that was used in Nickel/Metal hydride cell. The performances in terms of electrochemical utilization of nickel hydroxide, specific capacity as a function of discharge current density and cycle life were examined and the nickel hydroxide electrode with 5% CaCO(3) addition, having 200 mAh g(-1) specific capacity, could be subjected to charge/discharge cycles at C/5 rate for more than 200 cycles without the capacity fading.