Cost function for treating wastewater in rural regions

摘要

The purpose of this paper was to provide an cost-effective methodology for assessing wastewater treatment technology. This methodology may be useful in the planning of treatment facilities in rural regions. The existing cost models focus mainly on municipal wastewater treatment plants, which mostly consider the influence of the capacity of plant ordinarily expressed as inhabitants or flow rate. In this paper, we propose a new model of cost function in rural regions that includes both the capacity of plant and the removal rate of pollutants. The water quality indicator chemical oxygen demand and NH3-N are chosen to be factors for a rural wastewater treatment model. The cost model enables us to understand the influence of pollutants' removal rate and to compare various treatment technologies from an economic point of view. The statistical information comes from a sample of 221 wastewater treatment plants in rural regions located in Changshu, Jiangsu province of China adopting four treatment technologies such as membrane bioreactor technology, sequencing batch reactor, purification tank, biological filter and artificial wetland.