• Clean Technology
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• v.17 no.2
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• pp.175-180
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• 2011

A novel multi-criteria decision making strategy is developed for the construction of industrial symbiosis network in eco-industrial park and the strategy is applied to the construction of acid/alkali wastewater neutralization network in Yeosu industrial complex. Acid (or alkali) wastewater is commonly generated in chemical industries, and it can be used as neutralizing agent for alkali (or acid) wastewater generated from another source. As a consequence, a large-scale industrial symbiosis network for wastewater neutralization can be constructed in petrochemical complexes where a large amount of acid/alkali wastewater is generated. In this study, substance flow model is constructed which describes the wastewater neutralization network and multi-criteria decision making strategy is applied to find a few candidate for industrial symbiosis network.

• Clean Technology
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• v.3 no.2
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• pp.87-93
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• 1997

A new process has been developed for nitrate and other salts removals from polluted waters. Alumina cement and calcium oxide served as precipitating agents to remove nitrate with stirring at basic pH. Low content of alumina in the commercialized alumina cements resulted in a increasing in nitrate removal yield. It is found that the compositions of aluminium and calcium are the most important factors in successful nitrate insolubilization. In order to remove high concentration of nitrate in polluted water, multi-stage precipitation was found to be very effective. Sulfate, chloride, and phosphate ions as well as nitrate were also removed by the precipitated reaction. After precipitation, post-treatments including Na2CO3 addition and neutralization with acid alleviated the level of aluminium and calcium in the treated water.