(452e) Technical And Economical Evaluation Of A System For The Treatment Of Liquid Industrial Residues In An Explosives Company

ABSTRACT This study was carried out in the Atacama Desert region of northern Chile where the availability of water sources are scarce. Consequently, it is necessary to optimize the use of this resource, requiring the development of more efficient productive processes and less dependency on the resource, as well as the implementation of technologies orientated to its reutilization not only in the same process, but for other uses such as irrigation and for human consumption.

The current laws in Chile for the quality and emission of water (CONAMA, 2004) require companies to analize and treat the liquid residues produced before elimination. For this reason it is necessary to consider alternatives from a technical point of view that are economically feasible. Currently they are using swimming pools for the evaporation of water.

The main objective of this project was to analyze the alternatives for the treatment of effluents generated by the company from a technical and economical point of view, with the aim of reduction and/or reutilization. The specific objectives involve the analysis of the existing procedures and laws for the emission of liquid residues, to establish a characterization of the liquid according to the procedure of emission, to design a system of treatment for residual waters (a current requirement), and to establish an economic evaluation of the proposed system.

In relation to the analysis of force regulations, it was necessary to check and analyze the application of the following regulations: The D.S. N º 609/98 that establishes the Norm of Exhaust of Industrial Liquid Residues to Systems of Sewerage; The D.S. N º 90/2000 that establishes the Norm of Emission of the Pollutants' Regulation associated with the Exhausts of Liquid Residues to Marine and Continental Superficial Waters; The D.S. N º 46/2002 that establishes the Norm of Emission to Underground Waters; The D.S. N º 351/92 that regulates the Neutralization of Liquid Residues Manufacturers unloaded into Masses/Bodies of Water or Systems of Compilation; The official Chilean Norm N º 1.333 that establishes the quality requirements of the water for different uses.

For the characterization of the wastewater, we analyzed the following: the consumption and use of the water, a water balance of the plant that considered the parameters of flow, quality and the source (re-circulated, fresh or purchased water). To make the water balance, the quantity and the water quality were defined as indicators. For the quantity, we took the information that the company possessed from previous works as a reference.

The quality of the water was measured before and after the process through experimental techniques. The water was characterized in several points of the industry according to the following physicochemical parameters pH, Alkalinity, Hardness, Conductivity, Redox potential, Solid in Suspension

This took into account the parameters specified by the Chilean rules of water quality. It was also considered to be the source of the water recirculation, or fresh water.

For the selection of a system for the treatment of residual water, the following points were considered: The characterization available for wastewaters; the force regulations; the technology available; the system designed for the treatment of residual waters that maximizes the reutilization of the water resource.

Finally a technical/economic study was carried out by means of the method of the present value, to analyze the budget feasibility of the project.