Field facility for research and demonstration of CSO treatment technologies

1997 ◽  
Vol 36 (8-9) ◽  
pp. 391-396
Author(s):  
D. Averill ◽  
D. Mack-Mumford ◽  
J. Marsalek ◽  
R. Andoh ◽  
D. Weatherbe
Keyword(s):  
Pilot Scale ◽  
High Rate ◽  
Uv Disinfection ◽  
Combined Sewer Overflows ◽  
Combined Sewer ◽  
Treatment Technologies ◽  
Test Threshold ◽  
Vortex Separator ◽  
Solid Liquid ◽  
Solid Liquid Separation

A pilot scale study of options for the treatment combined sewer overflows is being conducted in Ontario, Canada. The objective is to achieve primary clarification equivalency in simple, high-rate satellite treatment systems. Effluent disinfection will also be required where bathing beaches are to be protected. Long column settling tests conducted with CSO suspensions indicated that approximately 40% of the suspended solids was non-settleable at the test threshold of 0.3 m/h. The use of a cationic polymer as the sole coagulant in a three metre diameter vortex separator achieved at least 50% TSS removal at surface loads up to approximately 40 m/h. The effluents from solid/liquid separation operations using the polymer coagulation strategy were more amenable to UV disinfection than those produced with metal-based coagulants. This document has been updated to include experimental results to mid-1997.

Pilot-Scale Study of Satellite Treatment Options for the Control of Combined Sewer Overflows

1997 ◽  
Vol 32 (1) ◽  
pp. 169-184 ◽  
Author(s):  
J. SCHMIDT ◽  
P. SETO ◽  
D. Averill
Keyword(s):  
Treatment Options ◽  
Cost Effective ◽  
Pilot Scale ◽  
Combined Sewer Overflows ◽  
International Joint Commission ◽  
Pollution Problem ◽  
Combined Sewer ◽  
Vortex Separator ◽  
Sewer Overflows ◽  
Screen Performance

Abstract Combined sewer overflows (CSOs) have been recognized for many years as a pollution problem within the Great Lakes ecosystem. CSOs were identified as a source of contamination in 10 of the 17 Canadian “Areas of Concern” designated by the International Joint Commission, and were considered a major problem in Hamilton Harbour and the Metropolitan Toronto Waterfront. Satellite treatment systems (located upstream in the sewerage system) were identified as being significantly more cost effective than other CSO control options in a feasibility study conducted for Metropolitan Toronto. Consequently, a multi-agency initiative was established in 1993 to examine the treatment of CSOs at a pilot-scale facility in the City of Scarborough. The technologies evaluated during two experimental seasons in 1994 and 1995 included a vortex separator, a circular clarifier, a horizontal-flow plate clarifier and an inclined rotary drum screen. Performance of the technologies is being assessed against a draft policy proposed by the Ontario Ministry of Environment and Energy. Results to date have indicated that the vortex separator and the plate clarifier under “best conditions” were capable of 50% TSS removal and 30% BOD5 removal and should be capable of satisfying the policy.

High-Rate Retention Treatment Basins for CSO Control in Windsor, Ontario

2004 ◽  
Vol 39 (4) ◽  
pp. 449-456 ◽  
Author(s):  
Jian Guo Li ◽  
Harold Horneck ◽  
David Averill ◽  
J. Alex McCorquodale ◽  
Nihar Biswas
Keyword(s):  
Empirical Relationship ◽  
Pilot Scale ◽  
High Rate ◽  
Experimental Investigations ◽  
Combined Sewer Overflows ◽  
Column Tests ◽  
Dosage Range ◽  
Loading Rates ◽  
Combined Sewer ◽  
Removal Efficiencies

Abstract Experimental investigations were conducted to evaluate the effectiveness of a retention treatment basin (RTB) with polymer coagulation for the treatment of combined sewer overflows (CSO) at high hydraulic loading rates. The TSS removal efficiency of the pilot-scale RTB at a surface overflow rate (SOR) of 11 m/h was approximately 35% without chemical addition, and 80% with a polymer dosage range of 5 to 10 milligrams per gram of influent TSS. The results demonstrated that the use of polymer coagulation significantly improved TSS removal and allowed the SOR in the RTB to be significantly increased, resulting in smaller treatment units. An empirical relationship was established to estimate removal efficiencies as a function of overflow rate. The results also compared settling characteristics of CSO, obtained from long column tests, to removal efficiencies in the high-rate RTB.

Modelling and pilot plant investigations of high rate deep bed filtration with permeable synthetic filter media

2002 ◽  
Vol 2 (1) ◽  
pp. 223-232 ◽  
Author(s):  
R. Gimbel ◽  
A. Hahrstedt ◽  
K. Esperschidt
Keyword(s):  
Waste Water Treatment ◽  
Pilot Scale ◽  
High Rate ◽  
Deep Bed Filtration ◽  
Transport Efficiency ◽  
Brownian Particles ◽  
Solid Liquid ◽  
Solid Liquid Separation ◽  
Porous Plastic ◽  
Highly Porous

Permeable Synthetic Collectors (PSCs) are bodies of several millimetres consisting of a highly porous arrangement of fixed fibres or open-porous plastic foam. The advantages of the application of this media in deep bed filtration were studied. The theoretical analysis of the particle transport efficiency was based on the numerical solution of the flow field and on trajectory calculations for non-Brownian particles. Investigations with an endoscope allowed the consideration of the particle adhesion on the surface of the inner fibres. The resulting filter coefficients are compared with experimental data. The application of PSC filtration in a pilot scale unit for waste water treatment performs much better in contrast to conventional filter grains (sand, anthracite etc.), especially under high rate conditions. In the future, the deep filtration can be applied to new fields of the topic of solid-liquid separation with smaller units, lower pressure drop and higher filtration rates.

From basic investigations to pilot plant tests of depth filtration with permeable synthetic collectors

2001 ◽  
Vol 1 (2) ◽  
pp. 141-150
Author(s):  
A. Nahrstedt ◽  
K. Esperschidt ◽  
R. Gimbel
Keyword(s):  
Pilot Scale ◽  
High Rate ◽  
Transport Efficiency ◽  
Trajectory Calculations ◽  
Brownian Particles ◽  
Depth Filtration ◽  
Solid Liquid ◽  
Solid Liquid Separation ◽  
Porous Plastic ◽  
Highly Porous

Permeable Synthetic Collectors (PSCs) are bodies of some millimetres consisting of a highly porous arrangement of fixed fibres or open-porous plastic foam. The advantages of the application of this media in deep bed filtration were studied. The theoretical analysis of the particle transport efficiency was based on the numerical solution of the flow field and on trajectory calculations for non-Brownian particles. Investigations with an endoscope allowed the consideration of the particle adhesion on the surface of the inner fibres. The resulting filter coefficients are compared with experimental data. The application of PSC filtration in a pilot scale unit for wastewater treatment performs much better in contrast to conventional filter grains (sand, anthracite etc.), especially under high rate conditions. In the future, the deep filtration can be applied to new fields of the topic of solid liquid separation with smaller units, lower pressure drop and higher filtration rates.

Modified vortex separator and UV disinfection for combined sewer overflow treatment

1995 ◽  
Vol 31 (3-4) ◽  
pp. 263-274
Author(s):  
M. C. Boner ◽  
D. R. Ghosh ◽  
S. R. Harper ◽  
B. G. Turner
Keyword(s):  
Environmental Protection Agency ◽  
Uv Light ◽  
Water Environment ◽  
Field Tests ◽  
Uv Disinfection ◽  
Combined Sewer Overflows ◽  
Solids Concentration ◽  
Combined Sewer ◽  
Vortex Separator ◽  
Dissolved Air

This paper presents the results of a study to evaluate the efficiency of a modified vortex separator (MVS) and an ultraviolet (UV) disinfection unit for direct treatment of combined sewer overflows (CSOs). The MVS included dissolved air and coagulant addition. The effluent from the vortex separator was disinfected continuously using UV light. Bench-scale tests were performed on CSO samples to screen various coagulants and operating pressures for dissolved air. Field tests were performed at the CSO pilot facility where simulated as well as actual storm-generated overflow events were studied. Performance comparisons between the MVS and other CSO treatment technologies are presented. Results indicate that the MVS achieves pollutant removals superior to conventional sedimentation for the same surface loading rates, or can be hydraulically loaded several times higher than sedimentation to achieve the same results. The results also indicate that the MVS significantly improved solids concentration capability when compared to the conventional operation of the vortex separator. UV disinfection performance was dependent on TSS removal and showed promise for full scale implementation when combined with MVS treatment. This project was sponsored by the Water Environment Research Foundation and was a collaborative effort between ten participating organizations including the US Environmental Protection Agency (EPA), municipalities, consulting firms and equipment manufacturers.

Experimental abatement data of underflow baffles for removal of floatables in the CSOs of the Greater Montréal (Canada) area

2005 ◽  
Vol 51 (2) ◽  
pp. 65-70 ◽  
Author(s):  
John F. Cigana ◽  
Martin Couture
Keyword(s):  
Pilot Scale ◽  
Horizontal Velocity ◽  
Design Criteria ◽  
Operational Cost ◽  
Flow Conditions ◽  
Combined Sewer Overflows ◽  
Follow Up Study ◽  
Combined Sewer ◽  
Rapid Flow

Underflow baffles have gained in popularity over the years as a viable mean to intercept floatables in Combined Sewer Overflows (CSOs). This choice was mainly justified by the extremely low capital cost (CAPEX) and operational cost (OPEX) of this solution, although the efficiency of underflow baffles has never been clearly proven. The only similar application to underflow baffles are scum boards in grit chambers and clarifier. However, the flow conditions at CSOs vary considerably from those in grit chambers and clarifier. For this reason, review of the behavior of floatables in a rapid flow is paramount. Only then can comprehensive design criteria for underflow baffles and overflow chambers be suggested. Pilot scale tests, performed in a 17 metres long basin at various flowrates, had already shown that a critical horizontal velocity for floatables (Vcr) may develop in the overflow chambers. In this follow up study, the fate of intercepted floatables was investigated. It appears from this latest data that permanent capture of floatables decreases rapidly with an increase in the horizontal velocity of the flow, no matter what the baffle depth. Baffle depth increases capture at lower velocities (0.17 m/s) but become irrelevant at higher velocities (0.61 m/s). This data suggests that capture efficiency of existing underflow baffles in overflow chambers can be, at best, very low whenever the horizontal velocity increases above 0.30 m/s or 1 ft/s.

Pilot Plant Studies on Filtration of Raw Sewage Using Floating Filter Media and Multiple Filter Column Inlets

1993 ◽  
Vol 28 (7) ◽  
pp. 143-151 ◽  
Author(s):  
Mitsuo Mouri ◽  
Chiaki Niwa
Keyword(s):  
Filtration Rate ◽  
Pilot Scale ◽  
Primary Treatment ◽  
Medium Size ◽  
Filter Surface ◽  
And Performance ◽  
Run Lengths ◽  
Solid Liquid ◽  
Solid Liquid Separation ◽  
Soluble Components

The characteristics and performance of solid-liquid separation of raw sewage using floating media and multiple inlets were studied using pilot-scale equipment. Particles over 7 µm, representing approximately 80% of SS and 50% of BOD in raw sewage were efficiently removed. Smaller particles and soluble components, comprising a large part of total BOD, were difficult to remove by filtration. The maximum SS removal ratio (SSRR) and SS quantity removed per unit filter surface (SSR) was achieved using a medium size of 5.5 mm and a filtration rate of 150 µm/d. Inlet switching to a lower position significantly extended the filter run lengths and increased the total SS removed by filtration. Using 5.5 mm filter particles and a 150 m/d filtration rate, 80-89% of SS was removed, 38-42 kg of SS was removed per unit filter sectional area, and filter runs were 55-65 hours. The backwash-filtrate ratio was around 2%. The space requirement of this system will be significantly smaller than the ordinary primary treatment system judging from the trial design of a prototype plant.

Chemical pretreatment of combined sewer overflows for improved UV disinfection

2015 ◽  
Vol 73 (2) ◽  
pp. 375-381 ◽  
Author(s):  
J. Gibson ◽  
R. Farnood ◽  
P. Seto
Keyword(s):  
Light Transmission ◽  
Uv Light ◽  
Uv Disinfection ◽  
Cationic Polymers ◽  
Combined Sewer Overflows ◽  
Combined Sewer ◽  
Sewer Overflows ◽  
Pre Treatment ◽  
Low Charge ◽  
Very High

The aim of this research was to better understand chemical pre-treatment of combined sewer overflows (CSOs) for subsequent ultraviolet (UV) disinfection. Approximately 200 jar tests were completed. Alum (Al2(S04)3·12H2O) resulted in a higher UV light transmission (UVT), and equivalent total suspended solids (TSS) removal, than ferric chloride (FeCl3). An alum dose of 20 mg/L increased the UVT of the raw CSO from 30 to 60% after settling. The addition of 100 mg/L of alum maximized UVT reaching approximately 85%. Flocculation did not increase UVT. However, it did improve the removal of TSS. Cationic polymers worked quickly compared with metal coagulants, but only reached a UVT of 60%. A high positive charge density on the polymer improved the removal of turbidity when compared with low charge, but did not affect UVT. If the goal is to maximise UVT, a very high alum dose may be preferred. If the goal is to minimize coagulant dose with moderate UV performance, cationic polymer at approximately 3 mg/L is recommended.

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