Wetland systems for industrial effluent treatment in Argentina

MAINE, M.A.; HADAD H.R.; MUFARREGE, M.M.; DI LUCA, G.A.; SCHERANO, M.C.; PANIGATI M.C.; NOCETTI, E.; CAFFARATTI, S.E.; PEDRO, M.C.

Congreso; 8th International Symposium on Wetland Pollutant Dynamics and Control WETPOL 2019; 2019

Constructed wetlands (CWs) are a wastewater treatment technology applied worldwide. In Argentina,although the optimal conditions for their implementation, this technology is still scarcely developed. Ourresearch group has designed two wetlands for the final treatment of effluents from two metallurgicalindustries, which have been operating for the last 15 years. Both systems are free-water surface wetlands(FWSWs) that treat together industrial effluent and sewage of the factory facilities. Once optimized, theyworked efficiently, presenting high contaminant removals. Metals were removed efficiently, beingretained in sediment and roots of the plants. The retention mechanisms depended on the dominantvegetation. In the CWs studied, unexpected events occurred that were studied to evaluate the robustnessand durability of these systems. With the good results obtained in the treatment of these effluents, thistechnology began to spread in our country. Different companies requested the implementation of thislow-cost and environmentally friendly technology for the final treatment of their effluents. For thisreason, we studied their application for the treatment of different effluents. We designed and studied ahybrid wetland (HW), composed by a FWSW and a horizontal subsurface wetland (HSSW) for thetreatment of sanitary effluents from a pet care center. We studied complex effluents as landfill leachatesusing a VFW and a HW (VFW and FWSW). We compared the performance of two HW configurations(HSSFW-FWSW and FWSW-HSSFW) constructed in parallel at pilot scale for the final treatment of theeffluents rich in nitrogen from a fertilizer manufacturing plant. Effluents from the paper industry were treated with FWSWs and HSSFWs. In Argentina, large areas are generally available at manufacturing facilities while operation and maintenance costs are limiting factors. For these reasons, the use of FWSWs are a suitable alternative.Santa Fe (Argentina), our region, are located in the most important milk basins of Latin America. Wastewaters from the numerous dairy farms and dairy factories are either poorly treated or dischargeduntreated into surface water courses. We studied a HSSFW for the final treatment of dairy farm effluents. Treated effluent is used to clean the floors of the dairy farm. As the characteristics of dairy factory effluents depend on the manufactured milk product, different configurations of HWs are been studyingfor their final treatment.Santa Fe city is surrounded by natural wetlands receiving urban runoff effluents. Floating treatment wetlands (FTWs) are being studied to mitigate the impacts of urban runoff on receiving environments.Polishing treatment of metallurgical effluents with FTWs area also studied. The results of theaforementioned cases will be presented.