Dr. Tume-Zapata, Pedro

In an annual monitoring in the Copiapó valley, the concentration of Cu, Hg, and As in sediments was related to environmental transfer processes, these elements also being present in surface water. The goal was to evaluate the uptake of the mentioned elements in wild plants of the Copiapó Valley, to determine if these species could be indicator plants to prevent environmental risks in local agriculture. From the same monitoring, the uptake of the elements was determined in wild plants growing near the irrigation channels; canopy of Tessaria absinthioides, Equisetum giganteum, Arundo donax, Melilotus indicus, Cortaderia rudiscula, and Sarcocornia neei was analyzed for the same elements. These plants were able to uptake Cu, Hg and As in concentration between 19 and 4674.5 times the environmental limits allowed for edible plants. This result shows that crop plants can also capture contaminants elements due to the frequency of irrigation. These plants can be used as indicators for the diagnosis of capture of the pollutants elements by plants and to prevent environmental hazards to human health in agricultural products from the Copiapó valley

The removal of copper ions, from synthetic solutions, using walnut shell and olive pomace waste as biosorbents was studied. Synthetic copper solutions were used, and the contact time, initial pH, biosorbent dose, and initial concentration of copper ions were evaluated. The used particle size of both biosorbents was inferior to 600 µm. In the elimination of copper ions, the walnut shell reached 88% (30 min), and the olive pomace 86.5% (40 min). The maximum removal of copper ions was at pH 5 with both biosorbents. The elimination of copper ions was constant with increasing doses of bio-sorbent; however, a decrease close to 90% in the biosorption capacity was determined, when the dose of biosorbent increased from 1 to 10 g/L. The effect of the biosorption capacity increased proportionally with the initial concentration of copper ions; achieving biosorption of 8.3 and 12.9 mg of Cu+2/g of biosorbent, with walnut shell and olive pomace, respectively. Both biosorbent allowed copper ions removal close to 90%; however, to the olive pomace was not necessary a size reduction and had a higher copper ions biosorption capacity than the walnut shell.

The objectives of this study are (a) to determine the background concentration of As, Cd, Cr, Hg and Pb in Arica commune; (b) to determine the degree of soil contamination in Arica city using environmental indices and (c) to evaluate the human health risk of these potentially toxic elements. In the rural area of Arica commune, 169 samples were taken and 283 samples were taken in the urban area of Arica city. Total concentrations of Cd, Pb and Cr were determined by EPA 3052 and EPA 6010 C. Mercury was determined by EPA 7473. Arsenic was determined by EPA 7061A. The available concentrations of As and Cr were determined by dilute hydrochloric acid and EPA 6010C. Environmental indices were applied for pollution and US EPA model was used to evaluate human health risk. Background concentrations were As 18.2, Cd 1.12, Cr 73.2, Hg 0.02 and Pb 11.8 mg kg−1, respectively. Environmental indices show that soil samples are located between slightly contaminated to extremely contaminated. Human health risk analysis shows that children have higher levels of risk than adults. The analysis with available concentrations of As and Cr shows no carcinogenic risk for adults and children, but 81% and 98% of the samples were between 10–6 and 10–4, that means intermediate risk.