Beijing Southwest Water Toxic Organic Pollutants - Polycyclic Aromatic Hydrocarbons

This paper has introduced the classification,qualities,harms,origins and transfers rules of polycyclic aromatic hydrocarbons (PAHs);qualitatively and semi-quantitatively analyzed the PAHs in water on south-west region of Bei Jing with such methods as liquid-liquid extraction (L-LE),solid phase extraction (SPE),solid phase micro extraction (SPME),semi-penetrate membrane device (SPMD).Briefly,polycyclic aromatic hydrocarbons are molecules built up of benzene rings,which resemble fragments of single layers of graphite. They have planar structures and come in a wide variety of shapes and sizes. Five hundred kinds of compounds have been proved to be carcinogenic substance,in which PAHs are important ones. The great origins of PAHs in environment are activities of human beings,especially incomplete combustion of the fossil fuel,such as petroleum,coal and wood.For the lower water-solubility,the total contents of PAHs in water,especially in natural water,is at 10-9 quantitative level or less,so they have to be enriched with appropriate methods before being analyzing. L-LE and SPE are in common use. By using L-L extraction,the recovery is higher than using SPE,but lots of time is taken,a great deal of organic solvents are used up and secondary pollution comes into being. Although the recovery of SPE is lower,it can be used to enrich large quantity of water sample using up less organic solvent. A new handy technology - SPME has been devised in early 1990's. Its manipulating process is very simple and quick,which needn't any organic solvent,so it can be used at the sampling scene. SPMD has been developed in 1990's. By this method,non-polarity organic contamination can be fully enriched,the enrichment of biological effective contamination by aquatic creature can be simulated,and the biological effect of chemicals can be evaluated.Water samples in Guan Ting reservoir;Yang River water system and Yong Ding River system have been collected and then have been enriched with four methods introduced in the first paragraph. GC-MS has been used to detect the PAHs. Qualitative and semi-quantitative data have been reported,which will be offered to water conservancy department.