With the rapid development of China’s economy and society, most lakes in China are suffering from different degrees of heavy metal and organic pollutions, eutrophication and so on combined pollution problems, which seriously affect the safety of lake water supply, fishery and ecological system. Polycyclic aromatic hydrocarbon (PAH) is a kind of persistent organic pollutant widely existed in China’s lakes, of which most have cancerogenic, teratogenesis and mutagenesis etc. damages. Food is one of the main ways for PAH entering into human body. Algae are the primary producer of Eutrophication Lake. The adsorption and enrichment of PAH by Algae is the first step of PAH entering into the food cycle. The adsorption and enrichment of PAH by Algae may be affected by coexisting heavy metal in water body. However, there has not yet had relative knowledge in domestic and overseas.

Funded by the projects Research on Effect and Mechanism of Taihu Lake Cyanobacterial Bloom to PHA Occurrence, biological concentration and Food Cycle and Research of Aquatic Plant Liquid –containing semi-permeable membrane passive sampling device, In-situ Monitoring of Organic Pollutant in Lake Water Source and Application in Research of Bio-availability of National science Foundation of China, China Academy of Science Nanjing Institute of Geography and Limnology associate researcher Yuqiang Tao firstly developed the research on heavy metal (Cu2+, Cd2+and Ag+) affecting the absorption of PHA (phenanthrene, pyrene and benzopyrene [a]) by micorcystis aeruginosa and its functional mechanism. The research shows that: the cation-pi interactions formed between heavy metal ion and PHA accelerates the absorption of PHA by micorcystis aeruginosa; the acceleration caused by cation-pi interactions get larger with the increase of metal ion’s soft order and the strength of PHA’s pi electron donor; the acceleration to absorption of PHA caused by heavy metal ion revealed the trend of Cd2+ ≪ Cu2+ ＜ Ag+; the acceleration to absorption of PHA caused by the same heavy metal ion revealed the trend of phenanthrene＜pyrene ＜ benzopyrene [a]. On this basis, further studied heavy metal (Cu2+, Cd2+and Ag+) affecting the enrichment of PHA (phenanthrene, pyrene and benzopyrene [a]) by micorcystis aeruginosa and its functional mechanism. The results show that: the cation-pi interactions formed between heavy metal ion and PHA accelerates the enrichment of PHA by micorcystis aeruginosa; the acceleration caused by cation-pi interactions get larger with the increase of metal ion’s soft order and the strength of PHA’s pi electron donor; moreover, heavy metal ion also can change the property of dissolved organic matter in the solution, further change the freely dissolved concentration of PHA and then accelerate the enrichment of PHA by micorcystis aeruginosa. This kind of functional mechanism is closely related to the nature of heavy metal and PHA.

The related achievement has been published successively on famous journal Journal of Environmental Quality and Chemosphere in environmental sciences field. (Yuqiang Tao, Bin Xue, Zhen Yang, Shuchun Yao, Shanying Li. Journal of Environmental Quality 2014，43, 1–10；‚Yuqiang Tao, Bin Xue, Zhen Yang, Shuchun Yao, Shanying Li. Chemosphere, 2015, 119, 719–726). After researched on heavy metal affected the residual body of algae absorbing pentachlorophenol (PCP) (Water Research, 2012, 46, 3585-3594) and PHA (Journal of Hazards Materials, 2013, 261, 21 – 28)for the first time, Yuqiang Tao et al. Firstly revealed the effect of heavy metal to the absorption and enrichment of PHA by living algae and its mechanism, further proved that the concentration and nature of heavy metal and organic pollutant is the main affecting factor of affecting the absorption and enrichment of organic pollutant by algae. The series of research increase and perfect the knowledge of main biogeochemistry process and ecological risk of main persistent organic pollutant in lakes like PHA and PCP, which provides fundamental basis for comprehensive treatment of lake combined pollution.