Chirikona Florah, Filipovic Marko, Ooko Seline, Orata Francis
Department of Pure and Applied Chemistry, Masinde Muliro University of Science and Technology, Kakamega, Kenya.
Environ Monit Assess. 2015 May;187(5):238. doi: 10.1007/s10661-015-4425-6. Epub 2015 Apr 11.
A major ecological challenge facing Lake Victoria basin is the influx of chemical contaminants from domestic, hospital, and industrial effluents. Determined levels of perfluoroalkyl acids (PFAAs) in wastewater and sludge from selected wastewater treatment plants (WWTPs) in Kenya are presented and their daily discharge loads calculated for the first time within the Lake Victoria basin. Samples were extracted and separated using solid-phase extraction and ultra-performance liquid chromatography (UPLC)-MS/MS or LC-MS/MS methodology. All sewage sludge and wastewater samples obtained from the WWTPs contained detectable levels of PFAAs in picogram per gram dry weight (d.w.) and in nanogram per liter, respectively. There was variability in distribution of PFAAs in domestic, hospital, and industrial waste with domestic WWPTs observed to contain higher levels. Almost all PFAA homologues of chain length C-6 and above were detected in samples analyzed, with long-chain PFAAs (C-8 and above chain length) being dominant. The discharge from hospital contributes significantly to the amounts of PFAAs released to the municipal water systems and the lake catchment. Using the average output of wastewater from the five WWTPs, a mass load of 1013 mg day(-1) PFAAs per day discharged has been calculated, with the highest discharge obtained at Kisumu City (656 mg day(-1)). The concentration range of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) in wastewater was 1.3-28 and 0.9-9.8 ng L(-1) and in sludge samples were 117-673 and 98-683 pg g(-1), respectively.
维多利亚湖流域面临的一项重大生态挑战是来自生活、医院和工业废水的化学污染物流入。本文介绍了肯尼亚部分污水处理厂（WWTPs）废水中全氟烷基酸（PFAAs）的测定水平，并首次计算了它们在维多利亚湖流域内的每日排放负荷。采用固相萃取和超高效液相色谱（UPLC）-MS/MS或LC-MS/MS方法对样品进行萃取和分离。从污水处理厂获得的所有污水污泥和废水样品中，全氟烷基酸的含量分别为每克干重皮克（d.w.）和每升纳克，均能被检测到。生活、医院和工业废物中全氟烷基酸的分布存在差异，生活污水处理厂中的含量较高。在分析的样品中，几乎检测到了链长为C-6及以上的所有全氟烷基酸同系物，其中长链全氟烷基酸（链长C-8及以上）占主导。医院排放的废水对排放到城市供水系统和湖泊集水区的全氟烷基酸量有显著贡献。利用五个污水处理厂的废水平均产量，计算出全氟烷基酸的每日排放质量负荷为1013毫克/天（-1），基苏木市的排放量最高（656毫克/天（-1））。废水中全氟辛酸（PFOA）和全氟辛烷磺酸（PFOS）的浓度范围分别为1.3 - 28和0.9 - 9.8纳克/升，污泥样品中的浓度范围分别为117 - 673和98 - 683皮克/克。
