scholarly journals Innovative monitoring of combined sewer overflow (CSO) quality in the Liguori catchnment (Cosenza, Italy)

2012 ◽  
Vol 47 (2) ◽  
pp. 178-185 ◽  
Author(s):  
Patrizia Piro ◽  
Marco Carbone ◽  
Giuseppina Garofalo
Keyword(s):  
Chemical Oxygen Demand ◽  
Treatment Plant ◽  
Treatment Strategies ◽  
Oxygen Demand ◽  
Combined Sewer Overflow ◽  
Planning Approach ◽  
Combined Sewer ◽  
Wet Weather ◽  
Wet Weather Flow ◽  
Sewer Overflow

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.

scholarly journals Turbidity in Combined Sewer Sewage: An Identification of Stormwater Detention Tanks

2020 ◽  
Vol 17 (9) ◽  
pp. 3053
Author(s):  
Yang Liu ◽  
Liangang Hou ◽  
Wei Bian ◽  
Banglei Zhou ◽  
Dongbo Liang ◽  
...  
Keyword(s):  
Oxygen Demand ◽  
Surface Water Quality ◽  
First Flush ◽  
Combined Sewer Overflow ◽  
Detention Tank ◽  
Detection Approach ◽  
Combined Sewer ◽  
Wet Weather ◽  
Sewer Overflow ◽  
First Flush Effect

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.

Application of Faecal Sterol Ratios in Sediments and Effluents as Source Tracers

2001 ◽  
Vol 36 (4) ◽  
pp. 781-792 ◽  
Author(s):  
Chris Marvin ◽  
John Coakley ◽  
Tatiana Mayer ◽  
Mitra Brown ◽  
Lina Thiessen
Keyword(s):  
Meteorological Data ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Pig Manure ◽  
Combined Sewer Overflow ◽  
Physical Measurements ◽  
Combined Sewer ◽  
Sewer Overflow

Abstract An analytical method to determine faecal sterols was developed and applied to the analysis of samples including pig manure, sewage treatment plant sludge and combined sewer overflow effluent. Compounds including coprostanol (5β-cholestan-3β-ol), epicoprostanol (5β-cholestan-3α-ol), cholesterol (cholestan-5-en-3β-ol) and dihydrocholesterol (cholestanol, 5α-cholestan-3β-ol) were quantified in these source samples and their relative ratios calculated to investigate their potential application as source tracers. A mean coprostanol:epicoprostanol ratio of 7.6 ± 1.17 was calculated for pig manure samples from three Ontario livestock operations. This ratio was much lower (approximately 1.8) for sewage treatment plant sludge while the ratio for a combined sewer overflow effluent was very high (approximately 70). This approach, with the addition of physical measurements (e.g., current velocities) and meteorological data, may assist in determination of the influence of shore-based activities, including sewage treatment and livestock operations, on aquatic systems.

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
Keyword(s):  
Surface Runoff ◽  
Principal Component ◽  
Wastewater Effluent ◽  
Source Analysis ◽  
Tokyo Bay ◽  
Combined Sewer Overflow ◽  
Untreated Wastewater ◽  
Combined Sewer ◽  
Wet Weather ◽  
Sewer Overflow

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.

Accuracy of different sensors for the estimation of pollutant concentrations (total suspended solids, total and dissolved chemical oxygen demand) in wastewater and stormwater

2013 ◽  
Vol 68 (2) ◽  
pp. 462-471 ◽  
Author(s):  
Mathieu Lepot ◽  
Jean-Baptiste Aubin ◽  
Jean-Luc Bertrand-Krajewski
Keyword(s):  
Chemical Oxygen Demand ◽  
Suspended Solids ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Total Suspended Solids ◽  
Detection Methods ◽  
Time Step ◽  
Pollutant Concentrations ◽  
Uv Visible ◽  
Wet Weather

Many field investigations have used continuous sensors (turbidimeters and/or ultraviolet (UV)-visible spectrophotometers) to estimate with a short time step pollutant concentrations in sewer systems. Few, if any, publications compare the performance of various sensors for the same set of samples. Different surrogate sensors (turbidity sensors, UV-visible spectrophotometer, pH meter, conductivity meter and microwave sensor) were tested to link concentrations of total suspended solids (TSS), total and dissolved chemical oxygen demand (COD), and sensors' outputs. In the combined sewer at the inlet of a wastewater treatment plant, 94 samples were collected during dry weather, 44 samples were collected during wet weather, and 165 samples were collected under both dry and wet weather conditions. From these samples, triplicate standard laboratory analyses were performed and corresponding sensors outputs were recorded. Two outlier detection methods were developed, based, respectively, on the Mahalanobis and Euclidean distances. Several hundred regression models were tested, and the best ones (according to the root mean square error criterion) are presented in order of decreasing performance. No sensor appears as the best one for all three investigated pollutants.

CSO treatment strategy based on constituent index relationships in a highly urbanised catchment

2007 ◽  
Vol 56 (12) ◽  
pp. 85-91 ◽  
Author(s):  
P. Piro ◽  
M. Carbone ◽  
G. Garofalo ◽  
J. Sansalone
Keyword(s):  
Chemical Oxygen Demand ◽  
Suspended Solids ◽  
Treatment Effectiveness ◽  
Oxygen Demand ◽  
Biological Unit ◽  
Unit Operations ◽  
Physical Unit ◽  
Combined Sewer ◽  
Hydrologic Controls ◽  
Wet Weather

In urbanising catchments the variability of particulate matter (solids) and oxygen demanding constituents of wet weather and dry weather characteristics result in variable treatment effectiveness from physical unit operations and biological unit processes. Higher organic concentrations during dry weather flow are more amenable to biological unit processes while the higher inorganic loads generated largely by urban wet weather constituents and much larger flows can be more effectively treated or conditioned by physical unit operations, including ideally preceded by hydrologic controls. This study examines the relationships between total chemical oxygen demand (COD)t, dissolved chemical oxygen demand (COD)d, particulate chemical oxygen demand (COD)p and solids, measured as total suspended solids (TSS). Results also provide an index for selection and optimisation of treatment operations for combined sewer overflow (CSO) loads.

Methods to accompany and evaluate planning of combined sewer overflow treatment concepts for complex sewer systems

2014 ◽  
Vol 9 (1) ◽  
pp. 1-8 ◽  
Author(s):  
K. Klepiszewski ◽  
S. Seiffert ◽  
M. Regneri ◽  
E. Henry
Keyword(s):  
Expert Knowledge ◽  
Management Strategies ◽  
Treatment Strategies ◽  
Combined Sewer Overflow ◽  
Simulation Tools ◽  
Sewer Systems ◽  
Combined Sewer ◽  
Treatment Concepts ◽  
Sewer Overflow ◽  
Local Emissions

Simulation tools are in common use to evaluate combined sewer overflow (CSO) treatment concepts in complex sewer systems. However, the planning of CSO structures in a sewer system is a matter of local constraints, expert knowledge and trial and error. Common standards only provide general recommendations to plan CSO structures and work out management strategies. Additionally, modelling the emissions of complex sewer systems tends to result in comprehensive findings. Although, it is essential to understand local behaviour and interaction of CSO structures in a system to improve local and overall performance there is a lack of tools to illustrate comprehensive simulation results in a simple way. In this context the methods presented here are developed. These include clear illustrations of the as-is state in the catchment using Sankey diagrams to show relevant volume and pollutant flows. Furthermore, loading and treatment indicators are suggested to illustrate local loading conditions and treatment capabilities of CSO structures in relation to the overall system. Additional emission indicators provide information on local emissions and show interactions of CSO structures. The results indicate that the suggested methods contribute to an efficient evaluation of interactions and performances to improve treatment strategies in the planning phase.

Constructed wetlands for combined sewer overflow treatment in a Mediterranean country, Portugal

2013 ◽  
Vol 67 (12) ◽  
pp. 2739-2745 ◽  
Author(s):  
R. Amaral ◽  
F. Ferreira ◽  
A. Galvão ◽  
J. S. Matos
Keyword(s):  
Constructed Wetlands ◽  
Retention Time ◽  
Suspended Solids ◽  
Oxygen Demand ◽  
Total Suspended Solids ◽  
Mediterranean Country ◽  
Combined Sewer Overflow ◽  
Combined Sewer ◽  
Removal Efficiencies ◽  
Sewer Overflow

The use of constructed wetlands as a valuable and attractive method for combined sewer overflow (CSO) treatment has been demonstrated in several studies. In Portugal, a Mediterranean country having usually a long dry period, there are still no applications of this technology. The purpose of this research is to gather information and know-how required for the design and management of this type of infrastructure. A pilot-scale experimental setup for CSO treatment was installed and evaluated in situ, in terms of organic matter, total suspended solids and microorganism removal with emphasis on the results of the start-up. After 1 day of retention average removal efficiencies of 73–79% and 82–89% were obtained in terms of chemical oxygen demand (COD) and total suspended solids (TSS), respectively. During the remaining retention time a slower removal was observed. After 7 days, the COD removal efficiencies reached 86–91% and the TSS removal efficiencies reached 93–97%. On average, after 1 day, reductions of 1.2–2.0 log and 1.9–2.4 log, respectively, for total coliforms and Enterococcus were observed. For a retention time of 7 days these reductions attained 4.0–4.9 log and 4.4–5.3 log, respectively.

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