Chemical and agronomic characterization of sewage water from the Castellano deposit, Pinar del Río

Abstract

The reuse of wastewater in agriculture results in a future need in many countries, since this sector employs almost 70 % of available freshwater, and there have been reports on critical levels of water deficit in many regions around the world. Cuba is not exempt from these problems, and its national politics towards water promotes the implementation of this practice. Therefore, in the current paper, an attempt has been carried out to characterize and to assess the quality of mining sewage water and its use in agriculture. To achieve successfully this aim, five punctual samples were collected from the creek “Biajaca”, where sewage waters coming from Minas Castellano, in Minas de Matahambre, Pinar de Río are discharged. These five punctual samples to form one composed sample were combined and so the pH and electrical conductivity were measured. After filtering and keeping the proper conservation, the following elements Na, K, Ca, Mg, B, Al, Bi, Cd, Co, Cr, Cu, Fe, Li, Mn, Ni, Pb, Sr, Tl, Zn, As, Be, Sb, Se, Mo, V, Ti, S, P, Rb were determined through digestion in microwave and analysis by ICP-OES. On the other hand, the ions F^-, Cl^-, NO₂^-, Br^-, NO₃^-, PO₄^3-, SO₄^2- were determined by ion-exchange liquid chromatography. The results showed that it is a type of water characteristic of the study area, with an acid pH and salinity, permeability and toxicity indicators suitable for its usage in agriculture, as long as its acidity is pre-neutralized.