Journal of Life Cycle Assessment, Japan
Online ISSN : 1881-0519
Print ISSN : 1880-2761
ISSN-L : 1880-2761
Life Cycle Evaluation of Decolorization System Using Electrolysis for Colored Piggery Wastewater
Hotaka KAIYasuhiro ISHIBASHIIsao KAWAGUCHIMasahumi YOSHIDA,Takahiro NAKAMICHIShinichi KAMOHARAHiroki OHWAKIKoji ARIZONOTakehiro TAKEMASA
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JOURNAL FREE ACCESS

2009 Volume 5 Issue 3 Pages 403-412

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Abstract

Objective. Livestock wastewater from pig farmer is generally treated by activated sludge process. However, it turns to brownish color (colored piggery wastewater). Before discharging colored piggery wastewater, it is necesarry to decolorize. Colored piggery wastewater can decolorize by ozone treatment or ultraviolet treatment. However they need a lot of electricity, they will have a lot of CO2 emission and high environmental loads. Authors researched and developed the decolorization system by electrolysis. From the results of pilot test, Authors evaluated that it can utilize for decolorization. In this study, Authors carried out Life Cycle Assessment (LCA) for electrolysis, ozone and NaClO decolorization system. In LCA, at first, making input and output data such as resources for machine and chemicals and electricity for each decolorization system clearer, and inventory analysis was carried out. However, there is no LCA report for ozone generation system, rescorces for ozone generation sysytem was unknown. Authors reffered CO2, NOx and SOx generation from 3 EID as output datas for inventory analysis. From the result of inventory analysis, Authors evaluated the generation of CO2, NOx and SOx. And then Life Cycle Impact Assessment was carried out using by Life-cycle Impact-assessment Method based on End point modeling (LIME).
Results and Discussion. From the result of inventry analysis, CO2 emission of electrolyzed-decolorization, ozone-decolorization and NaClO decolorization that delocolize 10t colored piggery wastewater in a day were indicated 3.37×101kg-CO2, 5.26×101kg-CO2 and 3.51×101kg-CO2, respectively. NOx emission were indicated 1.88×10-2kg-NOx, 3.42×10-2kg-NOx and 7.07×10-2kg-NOx, respectively. SOx emission were indicated 6.36×10-3kg-SOx, 1.31×10-2kg-SOx and 1.20×10-2kg-SOx, respectively. The influence of electrolyzd decoroization system was the smallest in the result of Human Health, however, it was the largest Social Asset, Biodiversity and Primary Production. It has became chear that the influence of global warming and urban area air pollution on electrolyzed decolorization was the smallest. However, electrolyzed decolorization needs many titanium electrodes. The results of LCIA, the influence of resource consumption in electrolyzed decolorization was largest. The result of Single Index, Ozone decolorization system showed the smallest value. In case of setting up electrolyzed decolorization system instead of ozone decolorization system in 45% farmer, it indicated that a lot of CO2, NOx and SOx emission would control.$$br$$
Conclusion. This study carried out life cycle evaluation for electrolyzed decolorization system, ozone decolorization system and NaClO decolorization system. It has examined CO2, NOx and SOx emissions in Electrolyzed decolorization system were the smallest, however the influence of resouce consumption was largest.

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© 2009 The Institute of Life Cycle Assessment, Japan
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