[Permissible pollution bearing capacity model of water function zone based on the perspective of municipal wastewater discharge and its application]

Abstract

Permissible pollution bearing capacity was an important basis for the prohibiting pollution discharge and assessing responsibility in the regional water function zone. In order to adapt to the current 'county-based' water environmental management mode in water function zone, we exami-ned the permissible pollution bearing capacity from the perspective of municipal permissible pollution discharge. A municipal pollution discharge model was established to predict the permissible pollution bearing capacity, which was then applied to Liquan and Jingyang counties in the downstream of Jinghe River. The results showed that the permissible pollution discharge in Liquan and Jingyang counties were closely related to the river discharge, with the permissible pollution discharge in the flood season being higher than that in the dry season. The COD concentration in the water function zone of Liquan County exceeded water quality target from November to next March. Therefore, the pollution discharge in this period of Liquan County should be reduced. The value of the pollution discharge would affect the results for the calculation of permissible pollution bearing capacity. The municipal wastewater discharge model could obtain more reasonable results of permissible pollution bearing capacity by using relatively stable pollution concentration data. Overall, our results could provide the scientific basis for the strict system of water resource management.

Keywords: Jinghe River; municipal pollution discharge model; permissible pollution bearing capacity; permissible pollution discharge.