Low complexity wastewater treatment process in developing countries: A LCA approach to evaluate environmental gains

Reliable Life Cycle Assessment (LCA) indicators for wastewater treatment plants (WWTP) construction and operation phases are still a demand mainly in developing countries. Thus, the purpose of this paper was to present and discuss the environmental performance of a full-scale WWTP installed in a Brazilian city using LCA approach. The treatment process consists of a UASB reactor followed by constructed wetlands, which makes it particularly attractive to developing countries due to its operational simplicity. The Life Cycle Inventory (LCI) was developed from a WWTP design and operation data including those of untreated wastewater and effluent quality. The results show that the environmental impacts from construction phase should not be neglected in LCA studies of low complexity treatment technologies (e.g. UASB reactor, constructed wetlands and pond systems). There is a trade-off between the use of materials and energy for construction and the low energy and materials consumption during the operation phase in these systems. The majority share of hydroelectric generation in the energy matrix and the combination of anaerobic and natural processes for wastewater treatment have contributed to a smaller impact potential for the operation phase. The LCA approach should be associated with plans and actions to face the challenges of providing wastewater treatment in developing countries. Only in this way, compliance with the eco-efficiency targets and protect public health will be guaranteed.