Contribution Analysis of Life Cycle Assessment Factors for Potential Environmental Impact of Wastewater Treatment Process

Abstract

Pollutant removal efficiency and installation cost are important factors to consider wastewater treatment process. However, practically during its operation, the input sources such as chemical use, amount of electricity used, waste sludge and so on are different according to characteristic of wastewater treatment process. Furthemore negative environmental influence such as resource depletion, energy consumption, air contaminant when generating electric-power were not considered as assessment factor to select the treatment process. This study analyzed environmental impact of MAR and A2O process using LCA (Life Cycle Assessment) in order to estimate contribution of potential environmental effects between A2O process and MBR process of sewage plant in Korea. Each process was set as system boundary and LCIA (Life Cycle Impact Analysis) by inputs and outputs was carried on. Specialized extruded values were obtained with the results of LCIA. A2O process has slightly higher environment load then MBR process with EP (Eutrophicaiton Potential) value of 7.09E-03 (kg PO4 3-eq/kg) for the fomer and 7.26E-03 (kg PO4 3-eq/kg) for the later. This was understood as treatment efficiency of MBR process has more higher then A2O process. However, MBR process showed its GWP of 9.13E-01 (kg CO2 eq/kg) which is approximately 5 time larger than of A2O process showing 1.60E-01 (kg CO2 eq/kg). For an analysis based on each influence category, contribution rate of water pollutant process about both processes had over 95% on EP, however, it is showed that A2O process had 85%, MBR process had over 96% on electricity related to global warming on GWP. As the results represented, it is concluded to allow for electricity consumption and water pollutant based on treatment process are Key contributor on WWTP. Sewage treatment process has been evaluated by treatment efficiency, cost of maintenance, etc., however, negative environmental effect of global warming can be passing out easily if electricity is only concerned on maintenance cost of WWTP. That is understood as a way that leads sustainable improvement in the waste water treatment which is one of national base facility with evaluating process efficiency as well as environmental anlaysis on LCA.