Characterization of the potential impact of retention tank emptying on wastewater primary treatment: a new element for CSO management

2011 ◽  
Vol 64 (9) ◽  
pp. 1898-1905 ◽  
Author(s):  
T. Maruejouls ◽  
P. Lessard ◽  
B. Wipliez ◽  
G. Pelletier ◽  
P. A. Vanrolleghem
Keyword(s):  
Suspended Solids ◽  
Negative Impact ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Primary Treatment ◽  
Wash Water ◽  
Quebec City ◽  
Wide Variability ◽  
To Come

Theoretical studies have shown that discharges from retention tanks could have a negative impact on the WWTP's (Wastewater Treatment Plant) effluent. Characterization of such discharges is necessary to better understand these impacts. This study aims at: (1) characterizing water quality during emptying of a tank; and (2) characterizing the temporal variation of settling velocities of the waters released to the WWTP. Two full-scale sampling campaigns (18 rain events) have been realized in Quebec City and laboratory analyses have shown a wide variability of total suspended solids (TSS) and Chemical Oxygen Demand (COD) concentrations in the water released from the tank. Suspended solids seem to settle quickly because they are only found in large amounts during the first 15 min of pumping to the WWTP. These solids are hypothesized to come from the pumping in which solids remained after a previous event. When these solids are evacuated, low TSS containing waters are pumped from the retention tank. A second concentration peak occurs at the end of the emptying period when the tank is cleaned with wash water. Finally, settling velocity studies allowed characterizing combined sewer wastewaters by separating three main fractions of pollutants which correspond to the beginning, middle and end of emptying. In most cases, it is noticed that particle settling velocities increase as the pollutant load increases.

scholarly journals Real-scale comparison between simple and composite raw sewage sampling

2018 ◽  
Vol 8 (1) ◽  
pp. 124-131
Author(s):  
Paulo Sergio Scalize ◽  
Juliana Moraes Frazão
Keyword(s):  
Suspended Solids ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Oil And Grease ◽  
The City ◽  
Real Scale ◽  
Composite Samples

Abstract The present study performed a qualitative and quantitative characterization of the raw sewage collected at the entrance of the sewage treatment station of the city of Itumbiara, state of Goiás. Samples were collected every two hours over a period of seven consecutive days. Characterization of both point samples and composite samples was performed. The parameters analyzed were: temperature, pH, alkalinity, chemical oxygen demand, oil and grease, electric conductivity, total phosphorus, settleable solids, ammoniacal nitrogen, total suspended solids, volatile suspended solids, fixed suspended solids and turbidity. These results allowed us to verify that it is possible to perform the collection and analysis of a point sample, instead of a composite sample, as a way of monitoring the efficiency of a sewage treatment plant.

Treatment of tunnel wash water and implications for its disposal

2014 ◽  
Vol 69 (10) ◽  
pp. 2029-2035 ◽  
Author(s):  
M. Hallberg ◽  
G. Renman ◽  
L. Byman ◽  
G. Svenstam ◽  
M. Norling
Keyword(s):  
Traffic Safety ◽  
Urban Areas ◽  
Suspended Solids ◽  
Treatment Plant ◽  
Particulate Material ◽  
Wash Water ◽  
Polluted Water ◽  
Solids Concentration ◽  
Low Concentrations ◽  
Road Tunnels

The use of road tunnels in urban areas creates water pollution problems, since the tunnels must be frequently cleaned for traffic safety reasons. The washing generates extensive volumes of highly polluted water, for example, more than fivefold higher concentrations of suspended solids compared to highway runoff. The pollutants in the wash water have an affinity for particulate material, so sedimentation should be a viable treatment option. In this study, 12 in situ sedimentation trials were carried out on tunnel wash water, with and without addition of chemical flocculent. Initial suspended solids concentration ranged from 804 to 9,690 mg/L. With sedimentation times of less than 24 hours and use of a chemical flocculent, it was possible to reach low concentrations of suspended solids (<15 mg/L), PAH (<0.1 μg/L), As (<1.0 μg/L), Cd (<0.05 μg/L), Hg (<0.02 μg/L), Fe (<200 μg/L), Ni (<8 μg/L), Pb (<0.5 μg/L), Zn (<60 μg/L) and Cr (<8 μg/L). Acute Microtox® toxicity, mainly attributed to detergents used for the tunnel wash, decreased significantly at low suspended solids concentrations after sedimentation using a flocculent. The tunnel wash water did not inhibit nitrification. The treated water should be suitable for discharge into recipient waters or a wastewater treatment plant.

Evaluating the treatment performance of a full scale Activated Sludge Plant in Islamabad, Pakistan

2012 ◽  
Vol 7 (1) ◽  
Author(s):  
S. S. Fatima ◽  
S. Jamal Khan
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Suspended Solids ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Full Scale ◽  
Operational Parameter ◽  
Mixed Liquor ◽  
Treatment Performance

In this study, the performance of wastewater treatment plant located at sector I-9 Islamabad, Pakistan, was evaluated. This full scale domestic wastewater treatment plant is based on conventional activated sludge process. The parameters which were monitored regularly included total suspended solids (TSS), mixed liquor suspended solids (MLSS), mixed liquor volatile suspended solids (MLVSS), biological oxygen demand (BOD), and chemical oxygen demand (COD). It was found that the biological degradation efficiency of the plant was below the desired levels in terms of COD and BOD. Also the plant operators were not maintaining consistent sludge retention time (SRT). Abrupt discharge of MLSS through the Surplus Activated sludge (SAS) pump was the main reason for the low MLSS in the aeration tank and consequently low treatment performance. In this study the SRT was optimized based on desired MLSS concentration between 3,000–3,500 mg/L and required performance in terms of BOD, COD and TSS. This study revealed that SRT is a very important operational parameter and its knowledge and correct implementation by the plant operators should be mandatory.

scholarly journals The Efficiency and Reliability of Pollutant Removal in a Hybrid Constructed Wetland with Common Reed, Manna Grass, and Virginia Mallow

Water ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1445 ◽  
Author(s):  
Michał Marzec ◽  
Krzysztof Jóźwiakowski ◽  
Anna Dębska ◽  
Magdalena Gizińska-Górna ◽  
Aneta Pytka-Woszczyło ◽  
...  
Keyword(s):  
Total Nitrogen ◽  
Total Phosphorus ◽  
Constructed Wetland ◽  
Suspended Solids ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Total Suspended Solids ◽  
Common Reed ◽  
Pollutant Removal ◽  
Limit Values

In this paper, the pollutant removal efficiency and the reliability of a vertical and horizontal flow hybrid constructed wetland (CW) planted with common reed, manna grass, and Virginia mallow were analyzed. The wastewater treatment plant, located in south-eastern Poland, treated domestic sewage at an average flow rate of 2.5 m3/d. The tests were carried out during five years of its operation (2014–2018). The following parameters were measured: biochemical oxygen demand (BOD5), chemical oxygen demand (COD), total suspended solids, total nitrogen, and total phosphorus. The results showed that more than 95% of BOD5, COD, and total phosphorus was removed in the tested CW system. The average effectiveness of removal of total suspended solids and total nitrogen exceeded 86%. A reliability analysis performed using the Weibull probability model showed that the removal reliability in the tested CW was very high for BOD5, COD, total suspended solids, and total phosphorus (100%). The probability that the total nitrogen concentration in the treated effluents would reach the limit value (30 mg/L) established for effluents discharged from a treatment plant of less than 2000 PE (population equivalent) to standing waters was 94%. The values of all the pollution indicators in wastewater discharged to the receiver were significantly lower than the limit values required in Poland. The investigated hybrid CW system with common reed, manna grass, and Virginia mallow guaranteed stable low values of BOD5, COD, total suspended solids, and total phosphorus in the treated wastewater, which meant it was highly likely to be positively evaluated in case of an inspection.

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.

Performance and behaviour of planted and unplanted units of a horizontal subsurface flow constructed wetland system treating municipal effluent from a UASB reactor

2013 ◽  
Vol 68 (7) ◽  
pp. 1495-1502 ◽  
Author(s):  
Jocilene Ferreira da Costa ◽  
André Cordeiro de Paoli ◽  
Martin Seidl ◽  
Marcos von Sperling
Keyword(s):  
Suspended Solids ◽  
Subsurface Flow ◽  
Oxygen Demand ◽  
Post Treatment ◽  
Filter Medium ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Horizontal Subsurface Flow

A system composed of two horizontal subsurface flow constructed wetlands operating in parallel was evaluated for the post-treatment of UASB (upflow anaerobic sludge blanket) reactor effluent, for a population equivalent of 50 inhabitants per unit. One unit was planted with cattail (Typha latifolia) and the other was unplanted. The study was undertaken over a period of 4 years, comprising monitoring of influent and effluent constituents together with a full characterization of the behaviour of the units (tracer studies, mathematical modelling of chemical oxygen demand (COD) decay, characterization of solids in the filter medium). The mean value of the surface hydraulic load was 0.11 m3m−2d−1, and the theoretical hydraulic retention time was 1.1 d in each unit. Using tracer tests with 82Br, dispersion number (d) values of 0.084 and 0.079 for the planted and unplanted units were obtained, indicating low to moderate dispersion. The final effluent had excellent quality in terms of organic matter and suspended solids, but the system showed low capacity for nitrogen removal. Four-year mean effluent concentration values from the planted and unplanted units were, respectively: biochemical oxygen demand (BOD5): 25 and 23 mg L−1; COD: 50 and 55 mg L−1; total suspended solids (TSS): 9 and 9 mg L−1; N-ammonia: 27 and 28 mg L−1. The COD decay coefficient K for the traditional plug-flow model was 0.81 and 0.84 d−1 for the planted and unplanted units. Around 80% of the total solids present in the filter medium were inorganic, and most of them were present in the interstices rather than attached to the support medium. As an overall conclusion, horizontal subsurface flow wetlands can be a very suitable post-treatment method for municipal effluents from anaerobic reactors.

scholarly journals Evaluation of the efficiency of selected wastewater treatment plant

2012 ◽  
Vol 60 (1) ◽  
pp. 173-180
Author(s):  
Tomáš Vítěz ◽  
Jana Ševčíková ◽  
Petra Oppeltová
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Suspended Solids ◽  
Inorganic Nitrogen ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
Total Efficiency ◽  
Treatment Efficiency ◽  
Wastewater Treatment Process

This paper is focused on primary, secondary, and total efficiency evaluation of the wastewater treatment process for chosen small wastewater treatment plant (WWTP) located near the Moravian Karst. Eight wastewater samples were taken during one year in three sampling profiles of WWTP: biochemical oxygen demand (BOD), chemical oxygen demand (COD), suspended solids (SS), pH, ammonia nitrogen (N-NH4), nitrite nitrogen (N-NO2), nitrate nitrogen (N-NO3), inorganic nitrogen (Ninorg), total phosphorus (Ptotal). Treatment efficiency by reduction was calculated for all laboratory analyzed indicators and average values were determined for the whole period. Calculated treatment efficiency of indicators BOD, COD and suspended solids was compared with the permissible minimum treatment efficiency of discharged waste water by Government Regulation No. 61/2003 Coll., for the WWTP from 500 to 2 000 PE. Permissible minimum treatment efficiency is not legislatively determined for the primary and secondary level. The results of the work will be used especially to compare results with other similar works.Analyzed values ​​of parameters BOD, COD, suspended solids, N-NH4 at the outflow from wastewater treatment plant were compared with the permissible maximum values at the outflow of the WWTP which the municipality has an obligation to respect according to the decision issued by the District Environment Authority.

scholarly journals Characterization of brewery wastewater composition

2015 ◽  
Vol 9 (9) ◽  
pp. 1073-1076
Author(s):  
Abimbola Motunrayo Enitan ◽  
◽  
Josiah Adeyemo ◽  
Sheena K. Kumari ◽  
Feroz Mahomed Swalaha ◽  
...  
Keyword(s):  
Suspended Solids ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Organic Content ◽  
Water Bodies ◽  
Brewery Wastewater ◽  
Surrounding Water ◽  
Peak Period ◽  
Physicochemical Composition ◽  
Negative Effect

Industries produce millions of cubic meters of effluent every year and the wastewater produced may be released into the surrounding water bodies, treated on-site or at municipal treatment plants. The determination of organic matter in the wastewater generated is very important to avoid any negative effect on the aquatic ecosystem. The scope of the present work is to assess the physicochemical composition of the wastewater produced from one of the brewery industry in South Africa. This is to estimate the environmental impact of its discharge into the receiving water bodies or the municipal treatment plant. The parameters monitored for the quantitative analysis of brewery wastewater include biological oxygen demand (BOD5), chemical oxygen demand (COD), total suspended solids, volatile suspended solids, ammonia, total oxidized nitrogen, nitrate, nitrite, phosphorus and alkalinity content. In average, the COD concentration of the brewery effluent was 5340.97 mg/l with average pH values of 4.0 to 6.7. The BOD5 and the solids content of the wastewater from the brewery industry were high. This means that the effluent is very rich in organic content and its discharge into the water bodies or the municipal treatment plant could cause environmental pollution or damage the treatment plant. In addition, there were variations in the wastewater composition throughout the monitoring period. This might be as a result of different activities that take place during the production process, as well as the effects of peak period of beer production on the water usage.

scholarly journals STUDY OF THE PURIFICATION PERFORMANCE OF THE NATURAL LAGUNATING TECHNIQUE OF THE PURIFICATION STATION OF THE CITY OF OUTAT EL HAJ – MOROCCO

2020 ◽  
Vol XLIV-4/W3-2020 ◽  
pp. 189-193
Author(s):  
H. Ech-Chafay ◽  
M. Najy ◽  
F. Z. Talbi ◽  
A. El Ghazouany ◽  
M. Lachhab ◽  
...  
Keyword(s):  
Suspended Matter ◽  
Suspended Solids ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Climatic Conditions ◽  
Technical Solution ◽  
Purification Process ◽  
Average Yield ◽  
The City ◽  
The Town

Abstract. The availability of land and the climatic conditions encouraged by the geographical situation of Morocco, have pushed this country to adopt since the 90s natural leaning as being the technical solution most suited to the economic and climatic context, thus, many treatment stations wastewater has already been carried out. In order to assess the performance of the natural lagoon-type treatment plant in the town of Outat El Haj, we studied the physicochemical parameters of the raw and purified water from the plant. For this, we carried out a set of measurements such as: Temperature, pH and Electrical Conductivity (EC) (parameters on site), Biochemical Oxygen Demand (BOD5), Chemical Oxygen Demand (COD), Suspended Solids (TSS), Dissolved Oxygen, Hydrotimetric Titer (TH), Cl- Chloride, Organic Matter (OM), Orthophosphates, and Nitrates, in order to examine the reliability of this purification process in the study area. The purification yields observed in the treatment plant vary from 23 to 94.6% as an abatement for BOD5. This average yield varies between 22.3 and 89.8% for COD, between 22.6 and 90.6% for OM, and between 9.2 and 65.5% for suspended matter (suspended matter). The purification performance is negative to very low in nitrogen and Orthophosphates. The results of the analyzes showed that the purification yields of the natural lagoon-type station, low, variable and remain dependent on the season.

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