Introduction.

Laboratories in the educational sector that offer analytical services and generate dangerous residues of Cr (VI) in their methods must adopt special measures for its elimination as it is a highly carcinogenic species of a negative environmental impact.

Objective.

Heterogeneous photocatalysis and bioadsorption environmental alternatives were evaluated in the removal of Cr (VI) in liquid waste generated in analytical services laboratories of the University of Nariño.

Materials and methods.

In both methods a factorial design 23 with high and low levels was applied, allowing to optimize the variables: pH = 1, amount of photocatalyst (TiO2) 0.5 g and 30 minutes of irradiation with UV light for the photocatalysis; and the variables: amount of bioadsorbent (green banana peel) 1g, pH = 1 and contact time of 60 minutes from Cr (VI) concentration of 100 mg / L for bioadsorption. The efficiency of the two methods was evaluated by comparing means and the assessment of technical and environmental feasibilitiy from matrices.

Results.

From the liquid waste with a total chromium concentration of 2,116 mg / L, removal rates of 96.07 ± 0.65 % were obtained for photocatalysis and 99.9 % ± 0.01 for the bioadsorption process; the latter showing a better performance. Finally, the best technical and environmental feasibility was obtained for bioadsorption.

Conclusion:

Bioadsorption is shown as an eco-efficient process and is therefore presented as an environmentally sustainable option for the elimination of Cr (VI) in the management of hazardous waste.