Alternative Approaches for Upgrading Effluent Quality for Lagoon Based Systems

1993 ◽  
Vol 28 (10) ◽  
pp. 201-205
Author(s):  
Brian Evans ◽  
Stephen Nutt ◽  
Tony Ho ◽  
Henryk Melcer
Keyword(s):  
Suspended Solids ◽  
Total Population ◽  
Sewage Treatment ◽  
Effluent Quality ◽  
Waste Sludge ◽  
Clean Environment ◽  
Alternative Approaches ◽  
The Cost ◽  
Phosphorus Levels ◽  
Lagoon Systems

The province of Ontario is Canada's most populous province with over 8 million residents out of a total population of 27 million. The province has 512 sewage treatment plants of which 137 or 27% are lagoons. Improved environmental effluent quality standards since the introduction of the lagoons has resulted in many of these being unable to achieve proper effluent quality. Typical effluent quality requirements across the province require a minimum of secondary treatment, that is 15 mg/l of BOD and suspended solids and 1 mg/l of total phosphorus. The movement towards a clean environment has resulted in phosphorus levels as low as 0.3 mg/l TP and in an increasing number of cases, full nitrification year round. Because many of these lagoons serve small populations in the 100 - 3 000 population equivalents category, the cost of upgrading such lagoons to tertiary quality effluent is significant. Two approaches for upgrading conventional lagoon systems were evaluated. They are called the Sutton and New Hamburg processes after the towns in Ontario where they were first installed. The Sutton process consists of extended aeration plant, followed by polishing lagoons with waste sludge sent directly to the lagoons, while the New Hamburg process consists of conventional lagoons followed by intermittent sand filtration.

A Decade of Change at West-Southwest Sewage Treatment Works, Chicago, Illinois, U.S.A.

1984 ◽  
Vol 16 (12) ◽  
pp. 555-571
Author(s):  
Nicholas J Melas ◽  
Raymond R Rimkus
Keyword(s):  
Suspended Solids ◽  
Sewage Treatment ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
The West ◽  
West Side ◽  
Effluent Quality ◽  
Effluent Standards ◽  
Solids Processing

The Metropolitan Sanitary District of Greater Chicago's West-Southwest Sewage Treatment Works consists of the West Side Treatment Works, an Imhoff facility placed in operation in 1930, and the Southwest Sewage Treatment Works, an activated sludge plant placed in operation in 1939. This paper focuses on the decade of “1970's” and examines changes in plant operating procedures along with plant additions and improvements that were implemented in order to meet stringent water quality and effluent standards. The effect of the energy crisis and the measures taken at the West-Southwest Sewage Treatment Works to lessen its impact are reported. Over the study period, very costly and energy intensive solids processing operations were either curtailed or eliminated. New and innovative processes of sludge handling were developed and implemented. The net effect of these changes in solids processing coupled with modifications in the secondary wastewater treatment operations have resulted in a significant improvement in the effluent quality of the plant. In the early seventies, the effluent concentration for suspended solids, biochemical oxygen demand, and ammonia-nitrogen were 30, 23, and 12 mg/l, respectively; the corresponding values for these parameters in 1981 averaged 6, 6, and 1.4 mg/l.

Combination of up-flow anaerobic sludge blanket reactor and a novel cascade sponge reactor for sewage treatment

2011 ◽  
Vol 63 (6) ◽  
pp. 1255-1264 ◽  
Author(s):  
K. Patel ◽  
A. K. Mungray
Keyword(s):  
Fecal Coliform ◽  
Sewage Treatment ◽  
Total Coliform ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Combined Process ◽  
Effluent Quality ◽  
Anaerobic Sludge Blanket ◽  
The Cost

Performance of the combined process of up-flow anaerobic sludge blanket (UASB) reactor and cascade sponge reactor (CSR) for sewage treatment was studied. UASB-CSR system was operated at HRTs of 24 h, 16 h, and 8 h at an average wastewater temperature of 29°C. It comprises of the most efficient combined process not only for CODT (98.9%), BODT (98.5%), TSS (99.3%), total nitrogen (89.1%), total phosphorus (99.0%), total coliform (99.9%) and fecal coliform (99.9%) removal but also for reducing excess sludge production. Fecal coliform counts were found 23 MPN/100 ml only in final effluents. The effluent quality of the system sufficiently meets the discharged standards which regulate wastewater discharge into drains. The parameters of CSR are closely related to those of the potable water after certain advanced treatment which can be reused in many ways. Moreover, it does not require any external aeration and thus the cost associated with energy and devices required for aeration are cut to zero.

The UASB reactor as an alternative for the septic tank for on-site sewage treatment

2004 ◽  
Vol 48 (11-12) ◽  
pp. 221-226 ◽  
Author(s):  
A.L.S.S. Coelho ◽  
M.B.H. do Nascimento ◽  
P.F.F. Cavalcanti ◽  
A.C. van Haandel
Keyword(s):  
Suspended Solids ◽  
Sewage Treatment ◽  
Uasb Reactor ◽  
Septic Tank ◽  
Operational Cost ◽  
Large Area ◽  
Construction Costs ◽  
Effluent Quality ◽  
In Series ◽  
Proper Performance

Although septic tanks are amply used for on site sewage treatment, these units have serious drawbacks: the removal efficiency of organic material and suspended solids is low, the units are costly and occupy a large area and operational cost is high due to the need for periodic desludging. In this paper an innovative variant of the UASB reactor is proposed as an alternative for the septic tank. This alternative has several important advantages in comparison with the conventional septic tank: (1) Although the volume of the UASB reactor was about 4 times smaller than the septic tank, its effluent quality was superior, even though small sludge particles were present, (2) desludging of the UASB reactor is unnecessary and even counterproductive, as the sludge mass guarantees proper performance, (3) the UASB reactor is easily transportable (compact and light) and therefore can be produced in series, strongly reducing construction costs and (4) since the concentration of colloids in the UASB effluent is much smaller than in the ST effluent, it is expected that the infiltration of the effluent will be much less problematic.

Low Cost Packaged Sewage Treatment Plant for Production of High Quality Effluent at Small Works

1993 ◽  
Vol 27 (5-6) ◽  
pp. 405-412 ◽  
Author(s):  
B. Chambers ◽  
J. Whitaker ◽  
A. F. Elvidge
Keyword(s):  
Suspended Solids ◽  
Low Cost ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Ammonia Nitrogen ◽  
Aeration Tank ◽  
Effluent Quality ◽  
Demonstration Plant ◽  
The Uk

In the UK there are over 7000 small works which treat the sewage from populations of less than 10,000. Many of these works are at risk of non-compliance with effluent quality consents and options for improving the standard of treatment are being pursued by many utilities. WRc and Anglian Water Services have developed designs for packaged sewage treatment plants to serve populations in the range of 1000-10,000. A demonstration plant has been constructed at the Waterbeach STW of Anglian Water to serve a population of about 6,500. Target effluent quality is 15:20:5mg/l of BOD, SS and ammonia nitrogen respectively on a 95 percentile basis. Following plant commissioning a process performance evaluation programme was commenced in February 1991. Nitrification was established after about 6 weeks of operation but suspended solids values have been affected by the presence of a stable foam on the surface of the aeration tank. Process modifications have reduced the effect of this phenomenon substantially and effluent quality has improved.

Mineralisation and pathogen removal in gravel bed hydroponic constructed wetlands for wastewater treatment

1995 ◽  
Vol 32 (3) ◽  
pp. 49-58 ◽  
Author(s):  
J. Williams ◽  
M. Bahgat ◽  
E. May ◽  
M. Ford ◽  
J. Butler
Keyword(s):  
Constructed Wetlands ◽  
Suspended Solids ◽  
Significant Contribution ◽  
Sewage Treatment ◽  
Secondary Treatment ◽  
Strongly Correlated ◽  
Pathogen Removal ◽  
Effluent Quality ◽  
Gravel Bed ◽  
The Uk

Gravel Bed Hydroponics (GBH) is a constructed wetland system for sewage treatment which has proved effective for tertiary treatment in the UK and secondary treatment in Egypt. Significant improvements in effluent quality have been observed in 100 m long field scale beds planted with Phragmites australis, resulting in large reductions in BOD, suspended solids and ammoniacal N. For such GBH beds, operating optimally with a residence time of about 6 hours, 2 to 3 log cycle reductions in the counts of indicator bacteria, certain bacterial pathogens and viruses are typically obtained. However, the efficiency of mineralisation was strongly influenced by flow-rate and the prevailing temperature. In addition, in the UK, overloading of the treatment system reduced the efficiency of removal of faecal coliforms, probably due to decreased adsorption to biofilms. Faecal coliform counts were also more strongly correlated to BOD than suspended solids. As a secondary treatment process, pathogen removal was consistently better in Egypt than the UK. Although GBH constructed wetlands do not fully satisfy the WHO guidelines for unrestricted irrigation, they can make a significant contribution to the control of pathogens in developing countries.

Spatial and Temporal Water Quality Trends in Severn Sound, Georgian Bay, since the Introduction of Phosphorus Control Guidelines: Nutrients and Phytoplankton, 1973 to 1991

1995 ◽  
Vol 30 (4) ◽  
pp. 565-592 ◽  
Author(s):  
A.F. Gemza
Keyword(s):  
Total Phosphorus ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Soluble Reactive Phosphorus ◽  
Euphotic Zone ◽  
Water Clarity ◽  
Sewage Treatment Plants ◽  
Order Of Magnitude ◽  
Phosphorus Levels

Abstract Severn Sound continues to exhibit signs of eutrophication despite initial identification of the problem in 1969 and the construction of several sewage treatment plants since then. In general, improvements in trophic state indicators have been marginal, suggesting that the sewage treatment plants have had limited success in controlling phosphorus concentrations. These discharges likely contributed to the increased total phosphorus levels and consequently the higher phytoplankton densities of the nearshore waters. Phytoplankton biovolumes were on average one order of magnitude higher than in the open waters of Lake Huron with mean summer biovolumes as high as 8.0 mm/L. Algal biovolumes were most dense in Penetang Bay, which experienced limited exchange with the main waters of the sound. No significant long-term trends were observed. Water clarity was declining significantly, however, at a rate of -0.60 to -0.78 m/year throughout the sound except in Sturgeon Bay. Total phosphorus levels were highly variable from year to year; however, concentrations from a 20-year perspective were declining in the open waters at a rate of 0.70 µg/L/year, but response was limited in nearshore areas. In Sturgeon Bay, mean annual euphotic zone total phosphorus as well as soluble reactive phosphorus levels declined by as much as 50% following the construction of a sewage treatment plant with tertiary treatment. Phytoplankton genera typical of eutrophic waters continued to dominate the algal assemblage but members indicative of mesotrophic conditions have become apparent in some areas of the sound.

Performance Analysis of the Rotating Biological Contactor Process Based on Particle Fraction and Improvement of Final Effluent Quality

1991 ◽  
Vol 23 (7-9) ◽  
pp. 1457-1466 ◽  
Author(s):  
Kazuhiro Tanaka ◽  
Minoru Tada ◽  
Mitsuo Ito ◽  
Noritugu Shimizu
Keyword(s):  
Suspended Solids ◽  
Fine Particles ◽  
Wastewater Treatment Plants ◽  
Small Scale ◽  
Particle Fraction ◽  
Effluent Quality ◽  
Rotating Biological Contactors ◽  
Activated Sludge Processes ◽  
Fraction Method ◽  
Final Effluent

Biofilm processes are, in general, suitable for small-scale wastewater treatment plants. However, final effluent qualities of biofilm processes are not as good as those of activated sludge processes due to fine particles remaining in the effluents. To improve the effluent qualities of the Rotating Biological Contactors (RBC) process, the behavior of fine particles through the process and the removal of fine particles with solids-liquid separation methods, rapid filtration and coagulation-filtration, were investigated using the particle fraction method. The results are as follows:–An increase of the hydraulic retention time (HRT) in the RBC reactor reduced the amount of fine particles and increased the amount of coarse suspended solids of 44 µm or more in diameter, which are easily removed by clarification. Thus, the final effluent qualities were improved by the increase of HRT.–Suspended solids in effluent from the RBC process at the standard loading are so fine that improvement of the quality is not expected by only lowering the overflow rate of a final clarifier. In contrast, rapid filtration or a coagulation-filtration process is effective. The supended solid concentration and transparency of the effluent from the final clarifier was improved by a factor of two to four, and then BOD of the final effluent was removed by 40-85%.

The Development of Lagoons in Venezuela

1987 ◽  
Vol 19 (12) ◽  
pp. 55-60 ◽  
Author(s):  
M. Lansdell
Keyword(s):  
Treatment Option ◽  
Sewage Treatment ◽  
Operational Experience ◽  
Cost Information ◽  
Anaerobic Baffled Reactor ◽  
Space Saving ◽  
Under Construction ◽  
Space Requirements ◽  
New Generation ◽  
Lagoon Systems

The operational experience of early lagoons is outlined. The construction of a new generation of lagoons of 2000 PE to 1.000.000 PE capacity and associated practical difficulties are described. Those with innovative and space saving features treated in some detail. One includes an anaerobic baffled reactor with sludge draw-off facilities which entered service in September 1986 and which is being monitored for compliance with “Engelberg Requirements”. Cost information and space requirements for the different systems under construction are included.It is concluded that lagoon systems properly designed and sited are the most appropriate and indeed the only financially viable sewage treatment option to suit Venezuelan circumstances.

Danish Experience with Emergent Hydrophyte Treatment Systems (EHTS) and Prospects in the Light of Future Requirements on Outlet Water Quality

1990 ◽  
Vol 22 (3-4) ◽  
pp. 65-72 ◽  
Author(s):  
H.-H. Schierup ◽  
H. Brix
Keyword(s):  
Wastewater Treatment ◽  
Total Nitrogen ◽  
Total Phosphorus ◽  
Wastewater Treatment Plants ◽  
Sewage Treatment ◽  
Reed Beds ◽  
Effluent Quality ◽  
Multi Stage ◽  
Run Off ◽  
Stage System

Since 1983 approximately 150 full-scale emergent hydrophyte based wastewater treatment plants (reed beds) have been constructed in Denmark to serve small wastewater producers. The development of purification performance for 21 plants representing different soil types, vegetation, and hydraulic loading rates has been recorded. Cleaning efficiencies were typically in the range of 60-80% reduction for BOD, 25-50% reduction for total nitrogen, and 20-40% reduction for total phosphorus. The mean effluent BOD, total nitrogen and total phosphorus concentrations of the reed beds were 19 ± 10, 22 ± 9 and 6.7 ± 3.2 mg/l (mean ± SD), respectively. Thus, the general Danish effluent standards of 8 mg/l for N and 1.5 mg/l for P for sewage plants greater than 5,000 PE cannot be met by the present realised design of EHTS. The main problem observed in most systems is a poor development of horizontal hydraulic conductivity in the soil which results in surface run-off. Since the political demands for effluent quality will be more strict in the future, it is important to improve the performance of small decentral sewage treatment plants. On the basis of experiences from different types of macrophyte based and conventional low-technology wastewater treatment systems, a multi-stage system is suggested, consisting of sedimentation and sand filtration facilities followed by basins planted with emergent and submergent species of macrophytes and algal ponds.

Aeration and Water Hyacinths in Waste Stabilization Ponds

1987 ◽  
Vol 19 (12) ◽  
pp. 265-271
Author(s):  
P. R. Thomas ◽  
H. O. Phelps
Keyword(s):  
Biochemical Oxygen Demand ◽  
Suspended Solids ◽  
Oxygen Demand ◽  
Total Suspended Solids ◽  
Substantial Improvement ◽  
Additional Treatment ◽  
Coliform Bacteria ◽  
Effluent Quality ◽  
Stabilization Ponds ◽  
Water Hyacinths

The investigation was based on two facultative stabilization ponds initially designed to operate in parallel, and now receive wastewater in excess of their capacities from a fast expanding housing estate in the Caribbean Island of Trinidad. Because of the deterioration of the effluent quality relative to acceptable standards, an attempt was made to upgrade the ponds using water hyacinths at the early stages. However, from the results, it was clear that the introduction of water hyacinths in the test pond did not lead to any substantial improvement in the effluent because of the high loading on the pond. Therefore the ponds were modified to operate in series with surface aerators installed in the first pond. Initially, the effluent quality was monitored in terms of total suspended solids, volatile suspended solids, biochemical oxygen demand, faecal coliform bacteria, pH and dissolved oxygen with aeration in the first pond and no aquatic plants in the second pond. Although there was a significant improvement in the effluent quality, the values remained above the standards. As a result, water hyacinths were introduced in the second pond and the effluent quality monitored together with aeration in the first pond. The effluent quality improved with total suspended solids and biochemical oxygen demand values both as low as 10 mg/l in certain months, but additional treatment was needed to reduce faecal conforms.

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