The Water supply alternatives for industries located in the Rio de Janeiro Metropolitan Region (RJMR)

Abstract

Industries located in the Rio de Janeiro Metropolitan Region (RJMR), in operation and in the installation phase, have been facing an imminent situation of water scarcity by competing with the human supply for surface fresh water. These industries should develop water supply alternatives, aiming at a balance between availability and demand, as well as the conservation of water resources in the state. The research presented here develops a technical and economical assessment of water supply alternatives for RMRJ industries, mainly near Guanabara Bay. Water supply alternatives are evaluated due to abstraction of raw water from the Guandu River; desalination of sea water of Guanabara Bay and reuse of final effluents from Waste Water Treatment Plants (WWTPs) of RJMR, which can be implemented together, or independently. Water provision scenarios for the supply alternatives consider flows between 1,000 m³/h (0.28 m³/s) to 2,000 m³/h (0,56 m³/s). Financial analysis were made based on capital expenditure (CAPEX) and operating expense (OPEX) of water supply alternatives plus taxes, considering an asset depreciation time over 20 years (concession period) and amortization of deferred over 5 years. Results indicate the proposal to reuse water from municipal WWTPs for industrial use as the most attractive alternative, from an economic, regulatory and environmental point of view.

Keywords: Water scarcity; water supply alternatives; raw water intake; desalination; industrial reuse.