摘要:
废水样品采集是污染物含量测定的关键环节，只有保证采样过程得到有代表性的样品，才能确保测定的数据具有使用价值，因此，研究采样位置对采样代表性的影响具有重要意义。本文用相对误差法对废水典型污染物在不同流态下的空间分布作了研究。研究结果表明，层流状态污染物分布比湍流状态污染物分布更加具有不均匀性，简单的层流状态下取样得出的结果误差较大，要在层流状态下采得有代表性的样品，需多点采样混合，这就无疑使得采样工作量和难度都会增加，不利于现场的采样，而在湍流状态下采样，不管在哪层采样，均可获得较为接近的结果，不会产生较大的偏差。因此，根据本次研究结果，废水采样过程中采样位置优选湍流断面，避免层流断面。本研究与其它相关研究结果吻合，能为废水采样位置的选择提供理论指导。
Abstract:
Wastewater samples are a key link in the process of contaminants determination, and only the sampling process gets a representative sample, can the data be valuable. Therefore, sampling location has significant effect on sampling representative. This paper researches the spatial distribution of typical pollutants in wastewater in different flow states with the relative error method, in order to study the effect of sampling location for sampling representativeness. The results show that the pollutant distribution in laminar state is more heterogeneous than in turbulent state, and there will be more error in laminar flow condition; besides, multipoint samples need to be mixed for obtaining representative samples in the laminar state, which undoubtedly makes workload and difficulty of sampling increase, and is not conducive to field sampling. However, no matter which water layer, sampling in turbulent state can get closer results, and will not produce larger deviation. Therefore, according to the results of this research, turbulent section is preferred in the choice of wastewater sampling location, and avoids laminar flow section. This research is consistent with other research results, and can provide theoretical guidance for the choice of wastewater sampling location.