Abstract

GUERRA, María Fernanda; RODRIGUEZ, Diana Catalina  and  PENUELA MESA, Gustavo Antonio. Valuation of the pre-oxidation to remove organic dissolved carbón and reduce trihalomethanes in water purificationn. Rev. P+L [online]. 2016, vol.11, n.2, pp.55-65. ISSN 1909-0455.  https://doi.org/10.22507/pml.v11n2a5.

ABSTRACT Introduction. Organic matter in drinking water can cause problems to the purification plants, such as changes in the water's organoleptic properties, an increase of the purification costs and increases in the disinfection byproducts. Objective. Evaluate pre-oxidation as an alternative to improve the removal of disolved organic carbón (DOC) and/or reduce the formation of trihalomethanes during the purification processes. Materials and methods. Experiments were carried out by means of a jar test in which the efficiency of two coagulants (aluminum hydroxychloride and aluminum sulphate) and two oxidation agents (Hydrogen peroxide and chlorine dioxide) to remove DOC and reduce trihalomethanes as a byproduct of the disinfection with sodium hypochlorite. Turbidity, color, pH and UV₂₅₄ changes were also assessed. Results. In terms of DOC removal, there is a significant difference (p = 0,033) vetween the use of aluminum sulphate and aluminum oxychloride, and the latter is more efficient. Pre-oxidation improves the color removal and the turbidity, and only with hydrogen peroxide an increase in the DOC removal was proved. Conclusions. Pre-oxidation with H₂O₂ in purification processes is a feasible alternative to remove not humic and hjydrophilic organic matter. The trihalomethanes' values were not above those allowed in Colombia and USA, 200 µg/L and 80 µg/L, respectively.

Keywords : organic matter; chlorine dioxide; hydrogen peroxide; pre-oxidation; trihalomethanes.