Selection of outlet locations of marine discharge engineering in the Maogang economic development zone, Guangdong.

Abstract: In order to determine a suitable outlet location of wastewater marine discharge engineering in the Maogang economic development zone of Maoming city, Guangdong, the paper analyzed the hydrological conditions, marine environmental function zoning, sensitivity degree and economic cost near the Maogang district and initially identified two optional outlets: the industrial discharge area of the district (outlet A) and the Shuidong bay port area (outlet B).Then the marine numerical model ECOMSED was applied to simulate the physical self-purification ability of the waters and the seawater exchange capacity of the outlet A and outlet B, respectively. Before the application of the ECOMSED model, it was validated with the hydrological data of the Shuidong bay and its neayby waters provided by the estuarine and coastal institute of Sun Yat-sen university. The simulation result shows that the physical serf-purification ability of the outlet A is stronger than that of the outlet B under the most unfavourable situation, with smaller influencing scope for the outlet A when the concentration increment of COD_Mn is bigger than O.Olmg/L. In terms of seawater exchange capacity, the outlet A also turns to be better than B, with the water residence of the outlet B 2.7 times as much as that of the outlet A. Between the two schemes of outlet location of the engineering, the best outlet location was determined to be A. [ABSTRACT FROM AUTHOR]