scholarly journals Source analysis of perfluorocarboxylates in Tokyo Bay during dry weather and wet weather using sewage markers

2011 ◽  
Vol 8 (4) ◽  
pp. 355 ◽  
Author(s):  
Michio Murakami ◽  
Chiaki Morita ◽  
Takuya Morimoto ◽  
Hideshige Takada

Environmental contextAs perfluorocarboxylates can be carried by surface runoff to waters and cause adverse effects to aquatic organisms, we evaluated the contributions of wastewater and surface runoff to the concentrations of these compounds in Tokyo Bay during dry and wet weather. Sewage markers revealed that the surface runoff was a significant source of perfluorocarboxylates in the bay during wet weather. This finding leads to a greater understanding of sources and pathways of perfluorocarboxylates in waters. AbstractWe investigated the occurrence of perfluorocarboxylates (PFCAs) in Tokyo Bay during dry and wet weather and evaluated the contributions of wastewater effluent, untreated wastewater, and surface runoff by using two sewage markers, caffeine and crotamiton. ∑8PFCAs ranged from 11 to 185 ng L–1. Perfluorononanoate (PFNA) was the major species, followed by perfluorooctanoate (PFOA) and perfluoroheptanoate (PFHpA). Principal component analysis followed by multiple linear regression revealed that the PFCAs were derived mainly from wastewater effluent during dry weather, and jointly from wastewater effluent (59%) and combined sewer overflow (41%) during wet weather. We used caffeine-to-crotamiton ratios to evaluate the contributions of untreated wastewater and wastewater effluent. Estimated concentrations of wastewater-derived PFCAs were much lower than observed concentrations during wet weather, indicating the contribution of surface runoff to contamination. During a combined sewer overflow, surface runoff had a significant effect on contamination in the bay.

Author(s):  
Yang Liu ◽  
Liangang Hou ◽  
Wei Bian ◽  
Banglei Zhou ◽  
Dongbo Liang ◽  
...  

Combined sewer overflow remains a major threat to surface water quality. A stormwater detention tank is an effective facility to control combined sewer overflow. In this study, a new method for the selective collection of combined sewer sewage during wet weather based on real-time turbidity control is established to reduce the load of pollutants entering a river using a stormwater detention tank with a limited volume. There was a good correlation found between turbidity and the concentrations of total suspended solids (TSS) (R2 = 0.864, p < 0.05), total phosphorus (TP) (R2 = 0.661, p < 0.01), and chemical oxygen demand (COD) (R2 = 0.619, p < 0.01). This study shows that turbidity can be used to indicate the concentration of TSS, TP, and COD in the sewage of the combined sewer systems in wet weather. Based on the adopted first flush detection approach, total nitrogen (TN) and TP showed the first flush effect, whereas the first flush effect of TSS and COD was not obvious. The results show that it is impossible to effectively control combined sewer overflow by only treating the initial rainwater.


Author(s):  
Bryant McDonnell ◽  
◽  
Richard W. Hayslett ◽  
Nathanial J. Tetrick ◽  
◽  
...  

2012 ◽  
Vol 47 (2) ◽  
pp. 178-185 ◽  
Author(s):  
Patrizia Piro ◽  
Marco Carbone ◽  
Giuseppina Garofalo

Estimates of urban wet-weather flow pollutant loads are required to assess their impact on receiving waters and optimize wastewater treatment plant (WWTP) and combined sewer overflow (CSO) operations. In particular, a quantitative characterization of flow quality by means of fairly accurate monitoring is required for developing a rational planning approach and preferential treatment strategies. The main aim of this paper is to examine the qualitative–quantitative characteristics of wet-weather flow in an urbanized test catchment in Cosenza, Italy, and to compare three studied water quality constituent concentrations (total suspended solids (TSS), total chemical oxygen demand (CODt) and filtered chemical oxygen demand (CODf)) obtained by laboratory analyses to those measured by a UV/Vis spectrometer (‘spectrolyzer scan’), which represents a most modern and efficient spectrometric instrument requiring little maintenance. The results of such comparisons indicated the feasibility of using in situ spectroscopy to provide fairly accurate concentrations of the constituents studied, particularly in the case of CODt and CODf.


2007 ◽  
Vol 56 (1) ◽  
pp. 215-222 ◽  
Author(s):  
E. Alp ◽  
C.S. Melching ◽  
H. Zhang ◽  
R. Lanyon

An Use Attainability Analysis (UAA) has been initiated to evaluate what water-quality standards can be achieved in the Chicago Waterway System (CWS). There are nearly 200 combined sewer overflow (CSO) locations discharging to the CWS by gravity. Three CSO pumping stations also drain approximately 140 km2. Because of the dynamic nature of the CWS the DUFLOW model that is capable of simulating hydraulics and water-quality processes under unsteady-flow conditions was used to evaluate the effectiveness of water-quality improvement techniques identified by the UAA including CSO treatment. Several CSO treatment levels were applied at gravity flow CSOs to evaluate improvement in dissolved oxygen (DO). The results show that pollutant removal at CSOs improves DO to a certain degree, but it still was not sufficient to bring DO concentrations to 5 mg/L or higher for 90% of the time during wet weather at most locations on the CWS. Flow from the pumping stations results in substantial stress on DO since a huge amount of un-treated water with a high pollution load is discharged into the CWS in a short period of time at a certain location. The simulation results indicate that CSO treatment does not effectively improve DO during wet-weather periods on the CWS.


1993 ◽  
Vol 27 (5-6) ◽  
pp. 93-104 ◽  
Author(s):  
H. Brombach ◽  
C. Xanthopoulos ◽  
H. H. Hahn ◽  
W. C. Pisano

In 1987 the first vortex solids separator facility in Germany was installed for combined sewer overflow (CSO) control. The separation efficiency was optimized in the hydraulic laboratory using scaled down models with artificial tracers to simulate typical sewage particulates. The station has two parallel operating vortex separators and serves a connected and impervious area of about 11 hectares (ha) and 1,500 people. The specific storage volume of the station is 7.2 m3 per ha. Two evaluation programs were conducted. The first evaluation phase noted the operational reliability, hydraulic loads, overflow frequencies and water mass balances. The second phase monitored separation efficiencies. The evaluation showed that vortex solids separators are now ready for use in CSO control.


Sign in / Sign up

Export Citation Format

Share Document