This study examined the impact of using different analytical recovery practices to correct MP concentrations on the performance of count and mass balances of primary wastewater settling. Spiking tests using standard MPs were conducted to evaluate the influence of MP size and sample type on recovery. The derived recovery values were then used to correct MP concentrations and loads in a full-scale primary treatment facility. The results reveal substantial differences in recovery that were dependent upon MP size and sample type, underlining the necessity of incorporating these discrepancies when estimating MP concentrations. Omitting recovery considerations during MP concentration reporting led to underestimations of approximately 40 %. In contrast, incorporating MP size and sample type during recovery calculations fostered a more accurate representation of MP concentrations, thereby enhancing the closure of balance models. While a count balance model was not apparently improved through the use differential recovery, the mass balance model showed a significant improvement in closure, reducing the lack of balance from 30.2 % to 17.2 %. This discrepancy was primarily attributed to the differing proportions of the primary sludge stream load in each model. These findings highlight the importance of incorporating differential recovery into mass balance models and demonstrate the complementary nature of count and mass balance approaches in understanding the fate and transport of MPs in WWTPs. The results of this study have significant implications for improving environmental assessments, policies and engineering design of wastewater treatment processes.

中文翻译：

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实施差收率校正可提高废水处理中微塑料质量平衡的准确性


本研究检查了使用不同的分析回收方法校正 MP 浓度对初级废水沉降的计数和质量平衡性能的影响。使用标准 MP 进行加标测试，以评估 MP 大小和样品类型对回收率的影响。然后使用得出的回收值来校正全尺寸初级处理设施中的 MP 浓度和负荷。结果显示，回收率存在显著差异，具体取决于 MP 大小和样品类型，这强调了在估计 MP 浓度时考虑这些差异的必要性。在 MP 浓度报告期间忽略回收因素导致低估了约 40%。相比之下，在回收率计算过程中纳入 MP 大小和样品类型有助于更准确地表示 MP 浓度，从而增强平衡模型的收敛性。虽然计数平衡模型并未通过使用差分恢复得到明显改进，但质量平衡模型在闭合方面显示出显着改善，将平衡不足从 30.2 % 降低到 17.2 %。这种差异主要归因于每个模型中一次污泥流负荷的比例不同。这些发现强调了将差动回收纳入质量平衡模型的重要性，并证明了计数和质量平衡方法在理解 MP 在 WWTP 中的命运和运输方面的互补性。本研究的结果对改进废水处理过程的环境评估、政策和工程设计具有重要意义。