Source tracing of n-alkanes in Songhua Lake, based on correspondence analysis and geochemical index

摘要

This paper analyzes the source of n-alkanes in sediments spanning 63 years since 1943 from Songhua Lake, using the method of correspondence analysis and geochemical index. The area of Songhua Lake is 554 km(2), and its ecological problems affect hundreds of thousands of people in the basin. The concentration of total n-alkanes (C-13-C-36) in the sediments ranged from 20.39 to 168.35 mu g/g, averaged at 72.58 mu g/g, indicating that the Songhua Lake has an ecological risk of n-alkanes and should be taken seriously and protected. The analysis of geochemical indexes, including main carbon distributions (MH), LMW/HMW ratio, Paq, average chain length and so on, shows the n-alkanes in the Songhua Lake sediments are mainly derived from modern higher terrestrial plants, followed by human activities, and a small part from aquatic vascular plants and algae. Moreover, the source and sedimentary history of n-alkanes in Songhua Lake were carried out by corresponding analysis. And the correspondence analysis could be a feasible and effective means of source tracing.