焦炉逸散烟尘集中治理对苯并[a]芘排放的环境影响分析

Environmental Impact Analysis of the Centralized Governance for Coke Oven Fugitive Dust on the Emission of Benzo [a] pyrene

拟对现有焦炉采用逸散烟尘处理方案进行技术改造,增设1套装煤、推焦过程逸散烟尘的收集处理装置。该处理装置由烟尘收集罩、烟尘收集处理设施和防风网三部分组成,设计烟尘捕集率为65%,除尘效率为99.0%。假设两种情景,采用AERMOD模型分别计算改造前/后焦炉炉体排放的苯并[a]芘的区域日均/年均最大地面质量浓度及其占标率,分析对周边区域大气环境的影响,并计算两种情景下的焦炉卫生防护距离。计算结果表明:改造后焦炉炉体排放的苯并[a]芘的区域日均最大地面浓度与改造前相比下降了92.4%,区域年均最大地面浓度下降了95.5%,区域日均最大地面浓度的超标区域面积减少了97.1%,区域污染物贡献浓度显著降低,净化效果明显,可以实现较好的环境效益;采用逸散烟尘处理方案后,焦炉的卫生防护距离经核定计算为1 000m,且防护距离内不涉及居民区,可满足环保管理的要求,对现有焦炉的运行具有现实意义。

This paper applies fugitive dust treatment scheme to technical reformation of existing coke oven, and adds 1 set of fugitive dust collecting and treating device in coal loading and coke pushing process. The device is composed of a dust collecting cover, dust collection and treatment facilities and windbreak net. The whole collection efficiency is 65% ,and dust removal efficiency is 99%. The paper assumes two situations, which are before and after the transformation of coke oven, calculates the daily/annual average maximum ground mass concentration and its scaling rate of Benzo [a] pyrene in region by using AERMOD model, an- alyzes the influence on the atmospheric environment of the surrounding area, and calculates the health pro- tection distance in the two situations. The results show that the daily average maximum ground concentra- tion in the area decreases by 92.4% compared with that before the reform,the annual average of the maxi- mun ground concentration in the area decreases by 95. 5%, and the area of th daily a verage maximum ground concentration of Benzo [a] pyrene exceeded the standard area decreases by 97. 1%. The contribu- tion of the regional pollutant is significantly reduced and the purification effect is obvious. The sanitary pro- tective distance of coke oven has been calculated and approved as lO00m,and it does not involve residential areas within the protection distance, and meets the requirements of environmental protection management. It has practical significance for the operation of existing coke ovens.