Bentonite effect on copper adsorption on plants irrigated with low quality water

Bentonite is a clay mineral with high cation exchange capacity and it has been evaluated as an alternative sorbent in removing metals in diverse environments. This study aimed to evaluate the effect of bentonite clay in adsorbing copper present in lower quality water in radish, corn and pasture grass. The experiments were carried out in a greenhouse, with a completely randomized design with four replications. The experimental units were plastic pots with a capacity of 5, 14 and 8 kg of soil for radish corn and grass, respectively. The soil was mixed with increasing doses of bentonite equivalent to 0; 30; 60 and 90 t ha-1. The sowing was done directly on the pot, leaving two plants per pot after thinning. They have been irrigated with poor quality water with a concentration of 1 mg L-1 Cu. Plants were harvested at 30, 60 and 70 days, separated in shoot and roots and placed in air circulation oven. The data were submitted to analysis of variance. Bentonite improved the development of radish and pasture grass crops; promoted the retention of copper in the soil, and favored the reduction of copper translocation to the shoot of corn, thereby reducing the concentration of this element in the aerial part.