City Sewage Treatment Plant Effluent Used For Landscaping Irrigation Of Perfluorooctanoic Acid In Health Risk Assessment

The papers cover research project sub-project of the National Natural ScienceFoundation of China (No.21277065). China currently has more than650organic cities, wherewater shortage in the city reached more than400seats.Faced with this grim urban waterdifficult, urban water shortages, China is eager to find a solution.Urban sewage plant effluentreuse It is a very reasonable one of the solutions.However, the complicated composition ofsewage plant effluent containing carcinogenic and non-carcinogenic chemical pollutants, anda variety of toxic and harmful viruses and bacteria.On the one hand people do not know muchabout recycling of sewage,on the other hand the wastewater reuse psychologically does notfully accept,so the scientific evaluation of wastewater treatment plant effluent back to thesecurity issues due transported born.Meanwhile, in recent years gradually became aware ofthe hazards of perfluorinated compounds (PFCs), especially perfluorooctane sulfonate (PFOS)and perfluorooctanoic acid (PFOA) is the most representative of the two types of substances,difficult to degrade and easy to migration characteristics have been widely perceived by thescientific community.And in2009the Stockholm Convention on the Persistent OrganicPollutants Review Committee adopted perfluorooctane sulfonic acid and its salts (PFOS)included in the resolutions of the Stockholm Convention.This study on the basis of previousstudies, Lanzhou and surrounding areas of the city sewage treatment plant water containingPFOA concentrations were determined. Combined back with the current situation of thehealth risk assessment. The following conclusions:（1）In the total of24times were samples,measured and analyzed of Lanzhou Anningand Qilihe sewage treatment plant effluent from May2012to April2013.Measured whereinthe concentration of PFOA:240.6ng/L-412.4ng/L.And in accordance with the plantwastewater reused for green the plant and a nearby park vegetation (ie Green irrigation) toconduct health risk assessment and the each crowd PFOA calculated health risk wascalculated by the health risk evaluation model.The results show that: between May2012toApril2013, the plant effluent total risk value of lifetime health hazards of career crowd(gardener):1.46E-11~2.32E-11;total risk value of lifetime health hazards of the tourists innon-career crowd:5.99E-13~9.55E-13;total risk value of lifetime health hazards of the plantstaff in non-career crowd:6.87E-13~1.10E-12.All risk values are lower than the theLanzhou lifetime maximum acceptable lifetime risk value7.3E-6.We can think whenLanzhou Anning and Qilihe sewage treatment plant effluent was reused for greeningirrigation,PFOA was basic safety on the human body. （2）The effluent from Lanzhou City and the surrounding areas a total of four sewagetreatment plant in late July were determined.The PFOA concentration in each plant effluentwere measured:Lanzhou City refinery sewage treatment plant306.5ng/L;LanzhouYanerwan sewage treatment plant342.4ng/L;Baiyin City sewage treatment plant389.1ng/L;Lanzhou Anning and Qilihe sewage treatment plant372.7ng/L。The each crowdlifetime risk calculation results of these4sewage treatment plant effluent was:total risk valueof lifetime health hazards of career crowd (gardener):1.37E-11~2.26E-11;total risk value oflifetime health hazards of the plant staff in non-career crowd:6.87E-13~1.10E-12;total riskvalue of lifetime health hazards of the tourists in non-career crowd:8.63E-13(only LanzhouAnning and Qilihe sewage treatment plant);total risk value of lifetime health hazards of thesurrounding farming farmers in non-career crowd:2.14E-11(only Baiyin City sewagetreatment plant).Also lower than the Lanzhou lifetime maximum acceptable lifetime riskvalue7.3E-6.That each sewage treatment plant effluent was reused for greening irrigation,thePFOA harm to human body is acceptable.In this dissertation, the research results will help China’s relevant departments tounderstand and master the content of the PFOA in Lanzhou sewage treatment planteffluent.And the hard targets on PFOA content is determined by the reuse purposes.Provide ascientific basis for our country’s future to control the PFOA contamination laws andregulations.Which can reduce PFOA secondary pollution and a potential threat to thepopulation health purposes.