炼焦粉尘中多环芳烃分布规律的研究

分别采集某焦化厂新、老厂地面站,炼焦焦炉和成品焦仓的4个排放筒粉尘样品,通过超声波萃取和高效液相色谱的方法,对炼焦过程中几个排污节点排放粉尘中富含的多环芳烃(PAHs)进行了分析.数据显示:炼焦焦炉排放筒中PAHs的质量浓度最高,达86.95μg·m~(-3);新厂地面站排放筒中PAHs的质量浓度最低,为6.09μg·m~(-3);从粉尘中PAHs单组分的分布特征来看,4个点位粉尘样品中共检出14种PAHs,菲和荧蒽的含量均很高,其中炼焦焦炉排放简粉尘中苯并b]荧蒽的含馈最高;4个样品粉尘中不同环数PAHs的分布规律为,主要以低环数的PAils为主,仅炼焦焦炉排放筒中的分布规律不一致,以高环数的PAHs为主;从排放筒排放物污染水平分析,以炼焦焦炉排放筒最为突出,粉尘的质量浓度为国家3级标准的75.7倍,苯并a]芘的质量浓度介于1级和2级标准之间.可见,焦化厂排放物对环境的污染严重,而炼焦过程中产生的多环芳烃对环境的污染更甚.

On the distribution regularity of PAHs in the coking dust

The present paper has been engaged in a comparative study and analysis of four kinds of dust samples of the emission tubes and obtained the distribution regularity of PAHs in the eoking dust.The re,arch work begins with the sample cokes respectively collected from the old factory spot, the new factory spot, the coke bin and the coke oven in the same eoking plant. The first three kinds of coke dust samples were removed by using bag dust eollecturs, while that from the coke oven was unable to get the coking dust removed. Then, the PAHs were analyzed by means of ultrasonic extraction and high performance liquid chromatography, which indicated that all the samples turned out rich and originated from the dust of the emission tube during the coking process. The results of our analysis prove that among the four kinds of dust samples, the PAHs from the coke oven turned out to be the richest with its content getting up to 86.95 μg· m~(-3).However, the mass content of PAHs in the new coking plant proved the lowest, whose mass content was only 6.09 μg· m~(-3). The paper has also analyzed the single component distribution of PAHs with 14 kinds of PAHs checked in the four dust samples, which were also over the standard stipulated by America EPA. The mass contents of phenanthtene and fluoranthene were also higher and Benzo (k) fluoranthene had extrusive contents in the coke oven. In addition, PAHs with different rings had different distributions in the four dust sampies. Comparative analysis shows that the dust prominently contained 2 and 3 rings PAHs in the old factory spot, the new factory spot and in the coke bin. The PAHs of the two ring types exceeded 67% among all the four. And in the three samples, the highest content of 2 and 3 rings PAHs was found in the old factory spot, that is,80.81%. The dust of coke oven mainly contained 4 and 5 high rings PAHs (86.32%). When the contamination level is analyzed, the principal contamination source comes from the coke oven, which was worked out as high as 5.95 times in BaP concentration of Grade Ⅲ.The concentration of BaP was counted merely between Grade Ⅰ and Grade Ⅱ. Therefore, coking plant emissions should be regarded as a serious pollution source to the environment with PAHs pollution even mote serious.