能量流评价——一种污水处理系统能耗评价的新方法研究

将污染物所含热值定义为污水的能量势,并根据能量势的变化与污水厂能耗的比值,定义了一种全新的污水厂能耗评价指标——能量流(Energy Flow,EF).能量流没有量纲,表示污水厂能耗作用于污染物处理效果上的能源利用效率.通过能量流和比能耗这2种方法对交互式反应器中试系统在改良A2O工艺下运行情况分别进行能耗评价发现:单位污染物比能耗与能量流呈很强的负相关性;处理水量是EF的主要影响因素之一,EF将随处理水量的增加而提高;能量流是一个从能量角度进行评价的的综合指标,其意义相当于一个由多个比能耗(各类去除物质)组成的评价指标体系.因此EF评价可以更清晰地反映污水厂能量利用效率,应替代比能耗作为污水厂运营的辅助参考依据.目前,能量流评价尚不完善,在其内涵中纳入反硝化过程以及除磷等相关生化反应将成为下一步的研究重点.

Energy flow: a new method of evaluating the energy consumption in a wastewater treatment system

Energy Flow (EF) is developed as a new energy consumption evaluating method by means of contamination energy potential conversion, which is defined as energy potential in this study. EF is an efficiency expression of the energy utilized directly in contamination removal. In addition, EF is a single energy consumption evaluating index that can serve as a multiple-target evaluating system with contamination removal (e.g. specific energy consumption indices, SECs). Therefore, EF evaluating is more direct to express the system integral energy consumption compared with SEC,which is generally used to evaluating wastewater treatment system energy consumption. The above two methods were used to evaluate the energy consumption of the pilot-scale experiment in modified A²O process. With the connotation of EF including both organic and inorganic matter removal, we found that SEC (per COD removal) is significantly negatively correlated with EF. Thereby, EF would be bound to present integral operation information. Moreover, sewage is a key factor affecting energy consumption efficiency, and increase of sewage quantity can enhance EF values. However, the definition of EF only limits to COD and ammonia currently. It is suggested to involve denitrification and phosphorus removal process in the future study to optimize the energy evaluating method.