污水处理系统碳排放规律研究与量化评价

发布时间：2018-03-14 13:24

本文选题：污水处理厂　切入点：碳质量平衡方程　出处：《西安理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：温室气体增加导致的全球气候变化正在对人类社会产生巨大的影响,减少温室气体排放已成为国际社会的共识。污水处理厂在运行过程中会直接或间接释放大量的CO2、CH4和N2O,被认为是主要的人为温室气体释放源之一。随着我国污水处理量大幅增加,污水厂节能减排的压力不断增大,如何针对城镇污水处理厂运行过程中碳释放状况,提出可行的减排措施,对于促进低碳城市建设具有重要意义。本论文以污水处理厂有机碳迁移转化为核心,采用碳质量平衡原理,确定了碳元素在系统中不同工艺环节之间的转化规律以及CO2、CH4和N2O释放的量化计算方法,并以西安市第四污水处理厂为例,进行了碳排放估算,提出了碳减排的措施,主要研究结论如下:(1)采用总有机碳(TOC)作为污水处理厂生物处理过程碳元素循环转化的监测手段,利用碳元素质量平衡原理,构建了不同生物处理工艺碳元素转化方程和CO2、CH4和N2O释放量的测算方法。(2)通过测定西安市第四污水厂不同生物处理工艺段的TOC,结合生物处理过程反应方程式,计算出生物处理过程中产生的CO2、CH4和N2O分别占到直接排放量的69.7%、27.9%、2.4%。根据碳元素平衡方程,计算得出全年的温室气体直接排放系数为0.230kgCO2/t水,全年直接排放量为38130.3tCO2;依据污水厂设备耗电量,核算出温室气体的间接排放系数为0.268kgCO2/t水,全年排放量为44501.6tCO2。西安市第四污水处理厂2016年温室气体排放量为8.26万吨CO2,其中直接排放量占45.9%,间接排放量占5 3.8%。在间接排放中水泵类设备和鼓风曝气系统排放的温室气体分别占总排放量的22.1%和25.7%,是减排的重点。可通过变频控制和精准曝气的方式减少温室气体的排放。(3)对污水处理厂碳排放进行了模型建立与网页软件开发。可计算一定周期内的污水处理厂碳排放水平,在输入污水处理厂处理规模、水质等数据及运行参数后可计算出该污水处理厂在计算周期内的碳排放直接排放、间接排放及其他排放。为污水处理厂制定减排管理措施提供参考。
[Abstract]:The global climate change caused by the increase in greenhouse gases is having a huge impact on human society. Reducing greenhouse gas emissions has become the consensus of the international community. Sewage treatment plants directly or indirectly release a large number of CO _ 2o _ (Ch _ 4) and N _ 2O during operation, which is considered as one of the main anthropogenic greenhouse gas emission sources. The pressure of energy saving and emission reduction is increasing in sewage treatment plants. How to put forward feasible measures to reduce carbon emission in the process of operation of urban sewage treatment plants, It is of great significance to promote the construction of low-carbon cities. In this paper, organic carbon migration and transformation in sewage treatment plants is the core, and the principle of carbon mass balance is adopted. The conversion law of carbon elements among different process links in the system and the quantitative calculation method of CO _ 2H _ 4 and N _ 2O emission were determined. Taking Xi'an 4th sewage treatment plant as an example, the carbon emission estimation was carried out, and the measures for carbon emission reduction were put forward. The main conclusions are as follows: (1) Total organic carbon (TOC) is used as the monitoring means of carbon cycling and transformation in the biological treatment process of wastewater treatment plant, and the principle of mass balance of carbon element is used. The carbon conversion equation of different biological treatment processes and the calculation method of CO _ 2N _ 2 Ch _ 4 and N _ 2O emission were constructed. The reaction equation of biological treatment process was combined with the determination of TOC of different biological treatment processes in Xi'an 4th sewage treatment Plant. The direct emission coefficient of CO2 CH4 and N2O in biological treatment was calculated to be 69.7% and 27.9% respectively. According to the equation of carbon element equilibrium, the direct emission coefficient of greenhouse gas was calculated to be 0.230 kg CO2 / t water. The annual direct discharge is 38130.3 t CO2. Based on the power consumption of sewage plant equipment, the indirect emission coefficient of greenhouse gas is calculated to be 0.268 kg CO2 / t water. In 2016, the greenhouse gas discharge of 4th sewage treatment plant in Xi'an was 82,600 tons of CO2, of which direct discharge was 45.9, indirect discharge was 53.8. the temperature of discharge of pump equipment and blast aeration system in indirect discharge was 45.9 and 53.8respectively. Room gas accounts for 22.1% and 25.7 of the total emissions, which is the focus of emission reduction. The carbon emissions of sewage treatment plants can be reduced by frequency conversion control and accurate aeration. Can calculate the carbon discharge level of sewage treatment plant within a certain period, After inputting the treatment scale, water quality and other data and operating parameters of the sewage treatment plant, the direct discharge of carbon from the sewage treatment plant during the calculation period can be calculated. Indirect discharge and other discharge. Provide reference for sewage treatment plant to formulate emission reduction management measures.
【学位授予单位】：西安理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X703

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