Abstract:
The awareness of possible environmental hazards caused by the widespread global use of volatile methylsiloxanes (VMSs) in personal care products (PCPs) and industrial processes has been increasing. Sewage containing these compounds may reach wastewater treatment plants (WWTPs), which are hotspots of their release into the environment. The levels, distribution, and potential risks of VMSs were studied in an unprecedently comprehensive sampling strategy (four seasonal campaigns) along the water line of a WWTP: the main influent entrance (SA1), after the preliminary treatment (SA2), after the primary treatment (SA3) and after the secondary treatment (the treated effluent; SA4). This WWTP was selected as a representative of the conventional set up based on a secondary treatment, allowing a similar approach in numerous facilities worldwide. Seven VMSs (L3, L4, L5, D3, D4, D5, D6) were analysed in wastewater samples by a small-scale liquid-liquid extraction (LLE) protocol, followed by gas chromatography-mass spectrometry (GC-MS), and the cyclic VMSs were dominant at all sampling sites and in all seasons. Considering the whole year, the total VMSs ranged from 0.4 to 22.5 μg L-1 for SA1, 0.03 to 33.7 μg L-1 for SA2, below method detection limit (MDL) to 13.2 μg L-1 for SA3 and 98 %). According to the risk quotients (RQ), only 18 SA4 samples (32 %) presented a minimal risk to the receiving media (0.01 ≤ RQ < 0.1). However, considering the absence of a secondary treatment or a direct discharge without treatment, there may be a risk to the environment.
摘要:
对个人护理产品(PCP)和工业过程中全球广泛使用挥发性甲基硅氧烷(VMS)可能造成的环境危害的认识一直在增加。含有这些化合物的污水可能会到达污水处理厂(WWTP),它们是释放到环境中的热点。的水平,分布,和VMS的潜在风险进行了前所未有的全面采样策略(四个季节性运动)研究,沿着污水处理厂的水线:主要流入入口(SA1),经过初步治疗(SA2),在初级处理后(SA3)和二级处理后(处理过的流出物;SA4)。该污水处理厂被选为基于二级处理的常规设置的代表,允许在世界各地的许多设施中采用类似的方法。通过小规模液液萃取(LLE)方案分析了废水样品中的七个VMS(L3,L4,L5,D3,D4,D5,D6),其次是气相色谱-质谱(GC-MS),循环VMS在所有采样地点和所有季节均占主导地位。考虑到全年,SA1的总VMS范围为0.4至22.5μgL-1,SA2的0.03至33.7μgL-1,低于方法检测限(MDL)的SA3至13.2μgL-1,98%)。根据风险商(RQ),只有18份SA4样本(32%)对接受介质的风险最小(0.01≤RQ<0.1).然而,考虑到没有二次治疗或不治疗直接出院,可能对环境有风险。