The removal of nickel from aqueous solutions and electroplating rinse effluent by Azolla biomass in batch and column experiments was investigated. The maximum nickel uptake by Azolla in the batch at an optimum pH of 6.5 was found to be 43.4 mg g(-1). The dried Azolla filiculoides showed good mechanical stability with repeated column operations at extreme pHs. Nickel uptake in column operation before 60% saturation of the biomass was found to be between 21.6 and 27.9 mg g(-1) with varying flow rates (from 16 ml h(-1) g(-1) to 160 ml h(-1) g(-1)). Complete desorption of bound nickel was achieved with 120 mi of either 0.2 N H2SO4 Or HCl. This, together with the data from regeneration efficiency for five cycles, provided evidence that the reusabilities of Azolla in treatment of nickel-laden wastewater are viable. An effluent free, closed-loop nickel treatment system, with Azolla biomass as the sorbent, is proposed.