Cost of remediation of the Lujan River (Argentina)

摘要

The objective of this study was to estimate the theoretical investment needed for the remediation of river water in the upper and middle course of the Lujan River (Buenos Aires province, Argentina). Two source of data were used: a) a monthly water sampling in the river over a 27 month period, and b) the Environmental Record of the Municipality of Lujan, where the estimated effluent discharges of the industries and the city of Lujan are registered. The number of days needed to produce the depuration of river water was estimated relating the biological oxygen demand (BOD) and the chemical oxygen demand (COD) with the dissolved oxygen concentration in water. In addition to this, and assuming that all the effluents that flow into the river do not exceed the DBO standards established by the legislation, the amount of oxygen needed to complete the self-depuration process of the river and the economic value of this process were estimated. Our results indicate that if industrial and sewage discharges were released in compliance with the existing legislation, the Lujan River has the capacity to depurate these effluents. Nevertheless, the "work" needed to process the effluents under the actual conditions exceeds from 3 to 10 times the real capacity of the river. To attain a sustainable use of the river, including recreation activities, it is essential to reduce the load of effluents, or to distribute the cost of river remediation among the main pollutant industries.