Strategies for Upgrading from Primary Treatment to Nutrient Removal at the Sandefjord Sewage Treatment Plant

1991 ◽  
Vol 24 (10) ◽  
pp. 187-194 ◽  
Author(s):  
Bjørn Rusten ◽  
Ragnar Storhaug

Different strategies for upgrading the Sandefjord primary treatment plant for nutrient removal have been evaluated. This plant is characterized by dilute wastewater, large flow variations and low wastewater temperatures. Phosphorus removal was evaluated based on full-scale tests at the plant. Nitrogen removal in submerged biological filters was evaluated based on literature data. Cost figures indicate that sewer rehabilitation, in order to reduce the flow and increase the influent wastewater concentrations, will be a good investment.

1998 ◽  
Vol 38 (2) ◽  
pp. 25-32 ◽  
Author(s):  
C. W. Chu ◽  
C. S. Poon ◽  
R. Y. H. Cheung

Chemically Enhanced Primary Treatment (CEPT) or Chemically Assisted Primary Sedimentation (CAPS) is being employed at the new sewage work on Stonecutters Island as part of the Strategic Sewage Disposal Scheme (SSDS) in Hong Kong. CAPS involves the use of chemical coagulants (such as lime or ferric chloride) to induce coagulation or flocculation and let these finely-divided particles form large aggregates (floc) so that they can settle out within a reasonable period of time. In this study, five sludge samples collected from different sewage treatment plants in Hong Kong were physically and chemically characterized. They were chemically modified sludge from Stonecutters Island (CAPS) raw sludge from Tai Po and Yuen Long Sewage Treatment Plant (STP) (rTP & rYL) and anaerobically digested sludge from Tai Po and Yuen Long STP (dTP & dYL). It was found that CAPS sludge was better than other 4 sludge samples in terms of settleability and dewaterability. CAPS sludge contained significant higher amounts (p<0.01) of extractable compounds than other sludges (except NO3− for dTP, NH4+ and PO43− for dYL). The concentration of total N and P in CAPS sludge were significantly higher (p<0.01) than other sludges (except dYL). The concentrations of total Cu, Pb, Ni, Cd, Cr and K in the CAPS sludge were also significantly higher (p<0.01) than other sludge samples. Most of the metals (Cr, Pb, Cr and Zn) in CAPS sludge were associated with the organically-bounded phase. It is concluded that there are significant differences in both physical and chemical properties between the chemically modified sludge and biological treated sludges.


2019 ◽  
Vol 15 (1) ◽  
pp. 40-44 ◽  
Author(s):  
Bikram Gautam ◽  
Anjita Rajbhanshi ◽  
Rameshwar Adhikari

Background: Water sources such as lakes, ponds, river etc. have been continuously contaminated by the   micro organisms and chemicals. The former can pose a significant threat to human health. This work aims at detecting the bacterial load before and after the sewage treatment and hence isolating pathogens from the sewage before primary treatment and secondary treated effluent. Methods: Grab sampling (50mL sewage before primary treatment and secondary treated effluent) was performed for 20 days in the Guheswori  sewage treatment plant. The reduction in microbial load was determined through heterotrophic plate count. Pathogens were screened from the effluent obtained from the secondary treatment plant. Results: Bacterial load reduction was found to be about 48.02% on average. The observed bacterial load reduction might have been caused by bacteriophage flocculation and sedimentation. Pathogens isolated from the treated effluent were Escherichia coli, Salmonella Typhi, Enterococcus faecalis, Staphylococcus aureus, Coagulase negative Staphylococcus (CONS), Citrobacter fruendii, Enterobacter aerogenes, Proteus mirabilis, P. vulgaris, Pseudomonas  aeruginosa. Conclusions: It has been found that the sewage treatment plant helps to reduce the bacterial load which is, however, not capable of effluent polishing where all pathogens are killed. 


2017 ◽  
Vol 43 (4) ◽  
pp. 58-65 ◽  
Author(s):  
Marta Małecka-Adamowicz ◽  
Łukasz Kubera ◽  
Wojciech Donderski ◽  
Katarzyna Kolet

AbstractThe study was aimed at evaluating microbial contamination on the premises of the sewage treatment plant by determining the concentrations of selected groups of airborne microorganisms. Another objective was to determine the antibiotic sensitivity patterns of isolated strains of staphylococci. The research was conducted in a seasonal cycle, by the impaction method using Merck MAS-100 air sampler. Samples were collected at six sites, each representing a different stage of sewage treatment. The susceptibility of isolated staphylococci was assessed with the disc-diffusion method, following the recommendations of the EUCAST. The results indicate that the microbial population in the air of the investigated area was dominated by mold fungi, whose highest average concentration was recorded at site IV located near the final clarifier (7672 CFU•m-3). Heterotrophic bacteria and mannitol-positive staphylococci were the most numerous at locations where sewage undergoes primary treatment. In each subseuqent stage the number of microorganisms emitted into the air from the sewage was lower. Antibiograms show that more than 50% of Staphylococcus spp. exhibited resistance to penicillin and 20% to rifampicin. In addition, 90% of the analyzed strains were sensitive to other antibiotics. The fungal community included the following genera: Cladosporium, Fusarium, Alternaria, Penicillium, Aspergillus, Aureobasidium, and Acremonium.The highest air contamination with all studied groups of microorganisms was recorded at the locations where mechanical sewage treatment was performed. During the subsequent stages lower numbers of heterotrophic bacteria were emitted into the air. The air in the investigated sewage treatment plant did not contain multidrug-resistant staphylococci.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5368 ◽  
Author(s):  
Anna Cristina P. Lima ◽  
Magali C. Cammarota ◽  
Melissa L.E. Gutarra

A residue from the primary treatment of a Wastewater Treatment Plant (WWTP) was used to isolate filamentous fungi with lipase production potential. Two of the 27 isolated fungi presented high hydrolysis index and were selected for lipase production by solid-state fermentation (SSF). The fermentations were conducted at 30 °C for 48 h, with moist air circulation, using 20% (w/w) of the residue mixture with a basal medium (agroindustrial residue—babassu cake), obtaining a solid enzymatic preparation (SEP) with lipase activity of 19 U/g with the fungus identified as Aspergillus terreus. Scum, collected in an anaerobic reactor operating in a WWTP, was hydrolyzed with SEP and subjected to anaerobic biodegradability tests at 30 °C. Different dilutions of crude (Control) or hydrolyzed scum in raw sewage were evaluated. The dilution of 5% (v/v) of hydrolyzed scum in raw sewage proved the most adequate, as it resulted in higher methane yield compared to the raw sewage (196 and 133 mL CH4/g CODadded, respectively), without increasing the chemical oxygen demand (COD) of the treated sewage (138 and 134 mg/L). The enzymatic hydrolysis of the scum, followed by dilution in the influent sewage, is technically feasible and increases methane production in anaerobic reactors.


1996 ◽  
Vol 33 (12) ◽  
pp. 147-153
Author(s):  
M. Rothman ◽  
J. Hultgren

Bromma sewage treatment plant (STP) is one of three plants in Stockholm. To meet more stringent requirements for nutrient removal the plant has been extended with a final filtration stage. Earlier it has not been possible to operate the plant with nitrification during winter time. Bad settling properties of the activated sludge have led to bulking sludge and high concentrations of BOD and phosphorus in the effluent. With the filter stage it is now possible to reduce the load on the biological stage by by-passing part of the flow directly to the filters. The result has been very promising and it seems that the plant can meet the new demands for nitrogen removal without extension of the aerated volumes.


2004 ◽  
Vol 50 (12) ◽  
pp. 79-86 ◽  
Author(s):  
D. Marani ◽  
V. Renzi ◽  
R. Ramadori ◽  
C.M. Braguglia

The objective of this work was to determine the partitioning of the pollutant load in urban wastewater in order to improve the conventional sewage treatment. In addition to settling tests, physical fractionation of COD in the degritted influent of Roma-Nord sewage treatment plant was performed via sequential filtration through sieves and membrane filters of the following pore size: 150-100-50-25-1-0.2 μm, and 100 kD (about 0.02 μm). Biodegradability studies were also performed on the different size fractions. Size fractionation showed that COD in Roma-Nord sewage is predominantly associated with settleable and supracolloidal (> 1 μm) particles, each size range including about 40% of total COD. Biodegradability tests indicated that the large fraction of COD associated with supracolloidal particles, which are not removed in the primary treatment, is characterised by slow degradability. This suggests that removal of these particles prior to biological treatment may greatly improve the overall treatment scheme. Preliminary pilot plant coagulation tests with lime at pH 9 showed that lime-enhanced primary treatment may increase COD removal efficiencies from typical 30-35% up to 65-70%, by inducing almost complete removal of the COD fraction associated with supracolloidal particles.


2021 ◽  
Vol 333 ◽  
pp. 12002
Author(s):  
Regina Damalerio ◽  
Aileen Orbecido ◽  
Michael Angelo Promentilla ◽  
Ramon Christian Eusebio ◽  
Liza Patacsil ◽  
...  

Water utilities, commercial and industrial establishments are required to upgrade or install new treatment systems to comply with the revised effluent standards issued by the Department of Environment and Natural Resources – Environment Management Bureau (DENR – EMB) which now includes removal and monitoring of nutrients (nitrogen and phosphorus components). One solution is to utilize a biological nutrient removal technology (BNRT) system capable of removing nutrients from sewage. The on-going study aims to investigate the performance of the pilot-scale system in the removal of nutrients from sewage. The designed pilot-scale anaerobic-anoxic-oxic (A2O) process with a total hydraulic retention time of 8.37 hrs. was operated in an existing sewage treatment plant (STP). System modification was adapted to ensure continuous operation. Dissolved oxygen (DO) and temperature of each compartment were evaluated after 45 days of system modification. The DO of the anaerobic and oxic compartment remained within the required range, while the internal recycling flowrate and/or aeration must be adjusted to achieve a DO concentration of 0.20 – 0.50 mg/L in the anoxic compartment. The research is financially supported by the Philippine Council for Industry, Energy and Emerging Technology Research and Development of the Department of Science and Technology (PCIEERD Project No. 04176).


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