Tryptophan-like fluorescence as a fingerprint of dry-weather misconnections into storm drainage system

Abstract

Background: Inappropriate dry-weather misconnections into storm drainage system are a demanding environmental problem worldwide, which leads to unexpected dry-weather discharge into surface waters. It often costs a large amount of manpower and resources to identify the source of misconnections and estimate its contributions. In this study, we evaluated the possibility of quantifying proportional source contribution in a storm drainage system with dry-weather misconnections from domestic sewage and river water inflow, using rapid and low-cost fluorescence spectroscopy methods. For this purpose, samples of both misconnection sources and outflows of storm drainage system were collected and analyzed in a downtown catchment of Shanghai, China.Results: Results showed that fluorescent peak intensity of tryptophan-like T 1 in domestic sewage (802 ± 126 a.u.) was significantly higher than that in urban river water (57 ± 12 a.u.), while fluorescent peak intensities of tryptophan-like T 2 in urban river water (732 ± 304 a.u.) was much higher than that in domestic sewage (261 ± 64 a.u.) due to increased algal activity in the local river and upstream inflow chemistry. However, only peak T 2 passed the conservative behavior test in the incubation experiments, which could be used as a fingerprint for quantitatively identifying the misconnections. We further developed a Bayesian fluorescence mass balance model (FMBM) to infer the percentage of dry-weather misconnections into the storm drainage system as a function of fluorescence intensities of peak T 2 in the samples of sources and outflow. It was found that the maximum posteriori probability estimate of the percentage of river water intrusion into the storm drains was up to 20.8% in this site, which was validated by the results of on-site investigation. Conclusion:Our findings implied that in situ fluorescent sensors and Bayesian FMBM for the fingerprint fluorescence peak could be applied to fast track inappropriate dry-weather misconnections into storm drainage system qualitatively and quantitatively with low costs.

Biogeochemistry of the dissolved organic matter (DOM) in the estuarine rivers of Bangladesh–Sundarbans under different anthropogenic influences

“…The emission wavelength at 270 nm in synchronous spectroscopy indicated the presence of tyrosine-like component ( Barker et al., 2009 ; Lu et al., 2021 ). This component could be predominantly originated from biodegraded or decomposed aquatic plants through biological activities ( Lu et al., 2021 ; Yin et al., 2020 ). The intensity of this substance was maximum in Kotka (5492 AU) and minimum in Harbaria (2035 AU) ( Figure 6 ).…”

Novel insights into impacts of the COVID-19 pandemic on aquatic environment of Beijing-Hangzhou Grand Canal in southern Jiangsu region

“…There is approximately 0.2-0.3 billion tons of TPDW discharged into aquatic environment in SJ region per year ( Xie and Ruan, 2013 , Jiangsu Provincial Bureau of Statistics 2019 ). Hence, the ratiocination from ( Yin et al, 2020 ) seemed reasonable. However, they did not try to confirm their inference.…”

“…In other surface water bodies of SJ region, several previous studies also found fluorescence features that were similar to those of water body in SJ-BHGC ( Qiu et al, 2012 , Yao et al, 2016 , Zhou et al, 2018 ). ( Yin et al, 2020 ) stated that the main sources of FDOM in water bodies of SJ region were probably related to the discharge of TPDW. The TPDI is a traditional pillar industry in Jiangsu Province and SJ is the area with the highest TPDI density in China ( Liu et al, 2017 ).…”

Linkages Between Optical and Molecular Signatures of Dissolved Organic Matter Along the Yangtze River Estuary-to-East China Sea Continuum

“…A previous study showed that there is high abundance of protein-like components in the Huangpu River, which flows into the Yangtze River between YE3 and YE4 (Dong et al, 2014). In addition, protein-like fluorescence components were found to be enriched in domestic wastewater (Yin et al, 2020), and one large wastewater treatment plant with a wastewater loading of 2.8 million m 3 /d is located nearby YE6. Therefore, the increase of C1 could be possibly attributed to the inputs of the Huangpu River (YE3 station) and the domestic wastewater treatment plant (YE6 station).…”