污水处理厂运行阶段碳排放动态变化分析：以深圳某污水处理厂为例

Analysis for Dynamic Changes of Wastewater Treatment Plant Carbon Emissions in Operation Phase:with a Wastewater Treatment Plant in Shenzhen as an Example

在节能减排的压力下,城镇污水处理厂碳排放日益受到关注。现有污水处理厂碳排放核算大都基于排放系数法,而且一般只估算年平均的碳排放。但实际上,污水处理过程中碳排放呈现动态变化,它与污水处理量、进出水水质、工况条件等密切相关。以深圳市某典型污水处理厂为例,将污水处理厂运行阶段的碳排放划分为能耗间接碳排放、物耗间接碳排放、CH_4直接排放和N_2O直接排放4部分,基于月变化的进出水水质、污水处理量、耗电量、药剂使用量等基础数据,采用混合的排放系数法估算逐月的碳排放,并分析影响碳排放动态变化的关键因子。结果表明,该污水处理厂各月吨水碳排放量波动较大,无明显季节性变化,波动主要受CH_4吨水排放量和N_2O吨水排放量的影响;吨水能耗碳排放和吨水物耗碳排放都呈现规模效应,而与进水水质和污染物去除率等指标无明显相关性;影响CH_4排放量和N_2O排放量的因素包括进出水水质、处理工艺、工况条件等。该方法可以识别污水处理厂运行阶段碳排放的动态变化规律,并为其减排提供科学依据。

Under the pressure of energy conservation,carbon emissions from urban wastewater treatment plant are highly concerned. The emission factor method has been widely used to estimate the average annual carbon emissions from a wastewater treatment plant. However,the emissions of wastewater treatment process are dynamic changed due to the variances of influence and effluent water quality,water quantity and working conditions. In this study,a typical wastewater treatment plant in Shenzhen is taken as a case study,the carbon emissions in operational phase is divided into indirect carbon emissions from energy consumption,indirect carbon emissions from material consumption,direct carbon emissions of CH_4 and N_2O. Based on monthly data of water quality,water quantity,energy consumption and material consumption,this study uses a hybrid emission factor method to estimate the monthly carbon emissions and further analyze their impact factors. The results indicate that the carbon emissions per unit volume of wastewater treatment have monthly fluctuation,but there is no significant seasonal variation. The monthly fluctuation is mainly due to the fluctuations of CH_4 and N_2O emissions per unit volume of wastewater treatment. Carbon emissions from energy consumption and material consumption per unit volume of wastewater treatment decrease with the increase of the wastewater treatment volume,but there is no significant correlation with the influent water quality and pollutant removal rate. The factors affecting CH_4 and N_2O emissions include water quality,treatment process,working conditions and so on. This method can identify the dynamic variation of carbon emissions and provide scientific basis for its reduction.