采油废水中多环芳烃的生态风险评价

先利用C-18固相萃取小柱富集大港油田港东联合处理站污水处理站的采油废水中16种多环芳烃(PAHs,即萘、苊烯、苊、芴、菲、蒽、荧蒽、芘、、苯并a]蒽、苯并b]荧蒽、苯并k]荧蒽、苯并a]芘、茚并1,2,3-cd]芘、二苯并a,h]蒽和苯并g,h,i]苝),再用气相色谱/质谱(GC/MS)分析测定其浓度,以评价PAHs的去除率和生态风险。结果表明:(1)采油废水经处理后,COD、石油类去除率分别达到82.27%、91.06%;外排水COD、石油类达到《污水综合排放标准》(GB 8978—1996)一级标准要求,优于中国采油废水处理的一般水平。(2)采油废水主要以2、3环的PAHs为主,约占总量的93%以上。(3)苯并a]芘超过《地表水环境质量标准》(GB 3838—2002)中限值。(4)处理前的采油废水中蒽、菲和苯并a]芘具有一定的生态风险;处理后的外排水中萘、蒽、菲、荧蒽、苯并a]芘的暴露浓度(PEC)/预测无效应浓度(PNEC)均小于1,目前尚未对环境造成威胁。但是8种PAHs(苊烯和苯并类PAHs除外)总和表现出较大的毒性,需要引起重视。

Ecological risk assessment of polycyclic aromatic hydrocarbons in petroleum wastewater

C-18 solid phase extraction column was used to enrich 16 polycyclic aromatic hydrocarbons(PAHs),which were naphthaline,acenaphthylene,acenaphthene,fluorene,phenanthrene,anthracene,fluoranthene,pyrene,chrysene,benzoa]anthracene,benzob]fluoranthene,benzok]fluoranthene,benzoa]pyrene,indeno1,2,3-cd]pyrene,dibenzoanthrace and benzoperylene,in petroleum wastewater.The concentrations of these PHAs were determined by gas-chromatograph/mass spectrometer(GC/MS) to evaluate their removal rate and ecological risk.After treated by aerobic pond,COD and petroleum pollutants of petroleum wastewater was decreased by 82.27%,91.06% respectively.The effluent COD and petroleum pollutants could meet I-class criteria specified in the integrated wastewater discharge standard(GB 8978-1996).The main species in petroleum wastewater was 2,3-polycyclic aromatic hydrocarbon,taking up over 93% of the total amounts of PAHs.Benzoa]pyrene exceed the limited value of surface water environmental quality standard(GB 3838-2002).Anthracene,phenanthrene and benzoa]pyrene in raw petroleum wastewater had a certain extent of ecological risk,while they threw no threaten to the environment after treatment because their PEC/PNEC lower than 1.However,the summation of 8 PAHs(except acenaphthylene and benzo kinds PHAs) showed high toxicity,and they deserved to be paid more attention.