Abstract:
The management of digested sludge derived from treatment water plants is a problem worldwide due to the possible transfer of contamination from sludge to amended soil and, in turn, to humans. Within this work, through a chemometric experimental design, a robust GC-MS method for the simultaneous determination of two classes of micropollutants of concern (polycyclic aromatic hydrocarbons-PAHs-and polychlorinated biphenyls-PCBs-including dioxin-like compounds) was developed using microwave-assisted extraction (MAE). The method, which showed interesting greenness features in compliance with the 12 principles of Green Chemistry, allowed PCB and PAH extraction with recoveries higher than 75% (RSD < 14%) with method detection limits between 4.6 and 11.5 µg kg-1 (PAHs) and between 6.9 and 13.7 µg kg-1 (PCBs), without preconcentration. The matrix effect was below 20%. The validated protocol allowed the characterization of two digested sludges sampled in an urban and a peri-urban district, representative models of two scenarios of different anthropic impacts. This study highlighted higher contamination for the sludge derived from the urban area, accounted for by the 4-ring PAHs. In addition, since carcinogenic PAHs were detected, the environmental risk (by mean of the comparison of predicted vs predicted no-effect concentrations) and the carcinogenic human risk from dermal contact (through the calculation of the adsorbed lifetime average daily dose) were assessed in the case of soils amended with the sludges considered, pointing out that the measured concentrations do not pose a risk.
摘要:
来自处理水厂的消化污泥的管理是一个世界性的问题,因为污染可能从污泥转移到改良土壤,反过来,对人类来说。在这项工作中,通过化学计量学实验设计,使用微波辅助萃取(MAE)开发了一种强大的GC-MS方法,用于同时测定两类关注的微污染物(多环芳烃-PAHs和多氯联苯-多氯联苯-包括二恶英类化合物)。方法,符合绿色化学的12条原则,显示出有趣的绿色特征,允许的PCB和PAH提取回收率高于75%(RSD<14%),方法检出限在4.6和11.5µgkg-1(PAHs)之间,在6.9和13.7µgkg-1(PCB)之间,没有预浓缩。基质效应低于20%。经过验证的协议允许对市区和市区周边地区采样的两种消化污泥进行表征,两种不同人为影响情景的代表性模型。这项研究强调了来自城市地区的污泥的较高污染,占4环PAHs。此外,因为发现了致癌的PAHs,在考虑污泥修正的土壤的情况下,评估了环境风险(通过预测与预测的无效应浓度的比较)和皮肤接触的致癌人类风险(通过计算吸附的终生平均日剂量),指出测得的浓度不会构成风险。