利用正构烷烃单分子碳同位素组成对兰州大气污染源的探讨

本文以兰州大气环境为试点，收集西固工业区、铁路商业-居民混合区和盘旋路交通要道区①取暖期（1994 年 3 月)和非取 暖期( 1994 年 8 月）的大气飘尘样品，固定污染源烟尘和汽车尾气样以及选择石油和煤的端元样品，利用MAT-252(GC-C-MC)仪进行正构烷烃单分子碳同位素测定。研究了大气飘尘、烟尘和尾气排放物中正构烷烃单分子碳同位素组成特征及分布规律，结合化石燃料（石油和煤）的分析结果提出了结果提出了冬季δ13C值高于夏季，西固工业区冬季、夏两季相似。经选择nC₂₁～nC₂₃单分子碳同位素值用二元复合估算结果，西固工业区大气污染主要为燃油源，市区内取暖期燃煤源输入率高，非取暖期主要来自燃油源，以汽车尾气为主，兰州市大气污染物中燃油源占60 %以上，这与用石油作为主要能源所造成的大气环境污染密切相关。

A Discussion on the Air Pollution Sources by Carbon Isotopic Compositions of N alkane Series

The airborne particulates w ere sampled from the Xigu indus trial area, the railw ay, commercial and resi- dential mixed area and Panxuan Circle road area during heating period (March, 1994)and nonheating period (August, 1994).The carbon isotopic compositions of n-alkane series of the samples were analyzed by a MAT 252 ins tru- ment (GC-C-I RM S) 、We investigated the characteristics and distributions of the carbon isotopic compositions and concluded that (1)the δ13C values in w inter resemble that in summer except that both are similar in the Xig u industial area., (2)The results, calculated using a two-end model of the carbon isotopic compositions from nC₂₁ and nC₂₃ show that the air pollution of the Xigu industrial area is mainly caused by oil burning, that of the urban district coal burning during a heating period and oil burning of automobile during a nonheating period, and (3) oil burning pollution matter makes up over 60 % of the organic pollution one, caused chiefly by oil burning.