School of Geography Earth and Environmental Science, University of Birmingham, Birmingham B15 2TT, UK E-mail:
RS Hydro Ltd, Leask House, Hanbury Road, Stoke Prior, Worcestershire B60 4JZ, UK.
Water Sci Technol. 2021 Jun;83(12):3075-3091. doi: 10.2166/wst.2021.197.
Reliance on biochemical oxygen demand (BOD) as an indicator of wastewater quality has hindered the development of efficient process control due to the associated uncertainty and lag-times. Surrogate measurements have been proposed, with fluorescence spectroscopy a promising technique. Yet, assessment of in-situ fluorescence sensors across multiple wastewater treatment plants (WwTPs), and at different treatment stages, is limited. In this study a multi-parameter sonde (two fluorescence peaks, turbidity, temperature and electrical conductivity) was used to provide a BOD surrogate measurement. The sonde was deployed at three WwTPs, on post primary settlement tanks (PST) and final effluent (FE). Triplicate laboratory measurements of BOD, from independent laboratories were used to calibrate the sensor, with high variability apparent for FE samples. Site and process specific sensor calibrations yielded the best results (R = 0.76-0.86; 10-fold cross-validation) and mean BOD of the three laboratory measurements improved FE calibration. When combining PST sites a reasonable calibration was still achieved (R = 0.67) suggesting transfer of sensors between WwTPs may be possible. This study highlights the potential to use online optical sensors as robust BOD surrogates in WwTPs. However, careful calibration (i.e. replicated BOD measurements) is required for FE as laboratory measurements can be associated with high uncertainty.
依赖生化需氧量（BOD）作为废水质量的指标，由于其相关的不确定性和滞后时间，阻碍了高效过程控制的发展。已经提出了替代测量方法，荧光光谱学是一种很有前途的技术。然而，对多个污水处理厂（WWTP）和不同处理阶段的原位荧光传感器的评估是有限的。在这项研究中，多参数探头（两个荧光峰、浊度、温度和电导率）用于提供 BOD 替代测量。探头部署在三个污水处理厂，在初级沉淀池（PST）和最终出水中。来自独立实验室的 BOD 重复实验室测量用于校准传感器，FE 样品的变化性明显。站点和工艺特定的传感器校准产生了最佳的结果（R = 0.76-0.86；10 倍交叉验证），并且三个实验室测量的平均 BOD 提高了 FE 的校准。当将 PST 站点结合起来时，仍然可以实现合理的校准（R = 0.67），这表明传感器在 WWTP 之间的转移可能是可行的。本研究强调了在污水处理厂中使用在线光学传感器作为可靠 BOD 替代物的潜力。然而，需要进行仔细的校准（即重复的 BOD 测量），因为实验室测量可能会存在高不确定性。
