Life cycle analysis of two Hungarian drinking water arsenic removal technologies

Abstract

Determining a technology's merit as a solution to Hungarian drinking water arsenic contamination goes beyond technical concerns: environmental and economic aspects also play very important roles. In an effort to address the current arsenic drinking water requirements in Hungary, life cycle analysis (LCA) methodology was applied on two example arsenic removal technologies, coagulation-filtration and adsorption, from cradle to grave. A distribution of 500 m3/day was assumed, along with a range of possible operation boundary conditions modelled solely for As treatment. Nine out of 10 considered impact categories tended to favour coagulation-filtration, however realistic variations in water chemistry and product characteristics led to some overlap of their environmental impact. Unlike other studies on water systems, electricity did not have a large direct impact; this was due to the focussed nature of this study on individual treatment technologies rather than an entire water supply system. Regeneration of the adsorption technology filter material was also observed to require nearly the same mass of materials for one regeneration as what was needed to support the coagulation-filtration technology for an entire year. Hazardous waste was surprisingly not reduced for adsorption compared to coagulation-filtration due to prefiltration requirements and an extra regeneration, even though adsorption shifts some of the environmental burden to the production phase. Additionally, cost analysis observes that coagulation-filtration is the cheaper of the two technologies; its highest cost is that of waste disposal, while the highest single expense modelled is that of the adsorption media cost.