Cost analysis and evaluation of urban sewage processing units

2005 ◽  
Vol 5 (6) ◽  
pp. 155-162
Author(s):  
M. Gratziou ◽  
S. Ekonomou ◽  
M. Tsalkatidou
Keyword(s):  
Cost Analysis ◽  
Oxidation Ditch ◽  
Sludge Dewatering ◽  
Waste Stabilization Ponds ◽  
Total Cost ◽  
Analysis And Evaluation ◽  
Urban Sewage ◽  
Waste Stabilization ◽  
Sludge Drying ◽  
Cost Components

This paper provides a comparative evaluation of the total cost for six conventional urban sewage processing units (complete-mix activated sludge, extended aeration and oxidation ditch, with either belt filtration or sludge drying beds for sludge dewatering respectively) as well as for two types of natural processing ones (waste stabilization ponds and horizontal flow subsurface constructed wetlands). This cost analysis emphasizes on cost components, such as construction cost, energy and chemicals costs, maintenance expenses and salaries. Analysis and estimation of cost functions was based on typical Greek cost prices. A percentage analysis of the total cost components is carried out and results for various treatment types are compared. Estimated results are compared to fiscal data collected from units in Greece.

scholarly journals A study of activated sludge dewatering in experimental reed-planted or unplanted sludge drying beds

1995 ◽  
Vol 32 (3) ◽  
pp. 251-261 ◽  
Author(s):  
A. Liénard ◽  
Ph. Duchène ◽  
D. Gorini
Keyword(s):  
Dry Matter ◽  
Matter Content ◽  
Second Phase ◽  
Dry Matter Content ◽  
Oxidation Ditch ◽  
Mineralization Process ◽  
Sludge Dewatering ◽  
Second Growth ◽  
Sludge Drying ◽  
Solids Content

The study was performed over the period from June 1989 to December 1992 on 3 experimental concrete beds of 20 m2 each, constructed close to an extended aeration plant. Beds 1 and 2 were planted with reeds, bed 3 was considered as an unplanted control bed. During the first phase (June 89-May 90), most of the reeds in bed 2 died in spite of the influent sludge dose of 70 g of SS m−2 d−1. During the second phase (917 days) the 3 beds were naturally aerated from the bottom and fed with sludge that was directly extracted from the oxidation ditch (Dry Matter content 0.3%). The influent sludge load varied between 120 and 160 g of SS m−2 d−1 after the second growth season (with peak values of up to 215 g of SS m−2 d−1 in the summer of 1991). Even if bed 3 didn’t clog, the major contribution of the reeds to maintaining a high and regular liquid conductivity in the sludge has been proven, allowing easier and higher dosing of the planted beds. Monitoring of the percolation flow emphasised a high mineralization process in the rhizosphere. The accumulated sludge (Total Solids content ≈ 11%) can be dug out together with the reeds using a mechanical digger and spread on fields with a manure spreader. A regrowth of reeds occurs directly from rhizomes remaining in the drainage layer and in a few centimetres of sludge at the bottom of the bed.

A New Technique for the Enumeration of Rotaviruses in Wastewater Samples

1989 ◽  
Vol 21 (3) ◽  
pp. 99-104 ◽  
Author(s):  
J. I. Oragui ◽  
D. D. Mara ◽  
S. A. Silva ◽  
A. M. Konig
Keyword(s):  
Inorganic Ions ◽  
Assay Method ◽  
Toxic Substances ◽  
Waste Stabilization Ponds ◽  
Virus Removal ◽  
Molecular Weights ◽  
Large Numbers ◽  
Waste Stabilization ◽  
A New Technique ◽  
Wastewater Samples

Rotaviruses are generally excreted in large numbers in diarrhoeal stools, but in wastewaters their numbers are subject to variations. Detection and enumeration of these viruses involve a concentration step followed by an assay method. Enumeration in wastewater concentrates is complicated by the presence of toxic substances which are often concentrated with the viruses. These toxic substances often cause the destruction of cells during rotavirus assay, thus leading to underestimation of viral numbers. Such concentrates were detoxified by a simple and effective method using polyacrylamide (Biogel P-6DG) or dextran (Sephadex G50) beads. Concentrates (10 ml) were mixed with 0.5 g gel and the mixtures were allowed to stand for 2 h at room temperature during which time the beads swell by the passage of water into them along with inorganic ions and substances with molecular weights of less than 30,000. The supernatants were then decontaminated with antibiotics and assayed for rotaviruses by the indirect immunofluorescent technique. Most untreated ultrafiltrates of raw sewage and those from anaerobic ponds were found to be too toxic to MA104 and LLC MK2 cells, whereas the above treatment rendered over 90% of wastewater concentrates non-toxic to cells. This technique was used to study virus removal in samples from deep waste stabilization ponds in northeast Brazil.

Rotavirus removal in experimental waste stabilization pond systems with different geometries and configurations

1995 ◽  
Vol 31 (12) ◽  
pp. 285-290 ◽  
Author(s):  
J. I. Oragui ◽  
H. Arridge ◽  
D. D. Mara ◽  
H. W. Pearson ◽  
S. A. Silva
Keyword(s):  
Clostridium Perfringens ◽  
Slow Process ◽  
Faecal Coliforms ◽  
Waste Stabilization Ponds ◽  
Stabilization Pond ◽  
Waste Stabilization Pond ◽  
Stabilization Ponds ◽  
Waste Stabilization

Rotavirus removal in waste stabilization ponds is a relatively slow process: in a series of ten ponds (a 1-d anaerobic pond followed by nine 2-d ponds) its numbers were reduced from 1.4 × 105 per litre to zero, and in an “innovative” series (a 1-day anaerobic pond, 3-d facultative pond, 3.8-d, 3-d and 5-d maturation ponds) from 5.1 × 104 per litre to <5 per litre. Faecal coliforms were better indicators of rotaviruses than was Clostridium perfringens .

Waste stabilization ponds in France: a report on fifteen years experience

1995 ◽  
Vol 31 (12) ◽  
pp. 91-101 ◽  
Author(s):  
Y. Racault ◽  
C. Boutin ◽  
A. Seguin
Keyword(s):  
Load Level ◽  
Organic Load ◽  
Nitrogen And Phosphorus ◽  
Waste Stabilization Ponds ◽  
Sewerage System ◽  
System Type ◽  
Stabilization Ponds ◽  
Waste Stabilization ◽  
Output Load

In 1992, a survey was conducted on the performance of waste stabilization ponds in France. The data selected come from a sample of 178 ponds, with an average capacity of 600 p.e., throughout France. For each plant, one or several input--output load measurements over a 24-h period are available. The average organic load level received is approximately 25 kg BOD/ha.d, representing 50% of the nominal load. The quality of the treated water is presented based on the type of sewerage system feeding the ponds. The results appear dispersed, however; in 70% of the cases the concentrations in COD and BOD on filtered samples are under 120 mg/l and 40 mg/l, respectively, and the concentration in TSS under 120 mg/l (discharge standards in France for waste stabilization ponds). The reductions in nitrogen and phosphorus nutrients are on average from 60% to 70%. The influence of different parameters (sewerage system type, organic load, season, age of plant, etc.) was studied. The results appear noticeably worse when the ponds receive wastewater from a strictly separate sewerage system.

scholarly journals Evaluation of contaminants removal by waste stabilization ponds: A case study of Siloam WSPs in Vhembe District, South Africa

Heliyon ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. e06207
Author(s):  
Joshua N. Edokpayi ◽  
John O. Odiyo ◽  
Oluwaseun E. Popoola ◽  
Titus A.M. Msagati
Keyword(s):  
South Africa ◽  
Waste Stabilization Ponds ◽  
Stabilization Ponds ◽  
Waste Stabilization ◽  
Contaminants Removal ◽  
Vhembe District

Penetapan Tarif Ambulans Untuk Evakuasi Medis Berbasis Unit Cost

2021 ◽  
Vol 7 (1) ◽  
pp. 167-173
Author(s):  
Kelvin Riupassa ◽  
Narizma Nova ◽  
Endah Lestari ◽  
Sri Juniarti Azis ◽  
Wahyu Sulistiadi
Keyword(s):  
Recovery Rate ◽  
Unit Cost ◽  
Cost Recovery ◽  
Maintenance Costs ◽  
Total Cost ◽  
Medical Evacuation ◽  
Operational Costs ◽  
Emergency Ambulance ◽  
The Cost ◽  
Cost Components

Background: An ambulance is a vehicle designed to be able to handle emergency patients, provide first aid and carry out intensive care while on the way to a referral hospital. Ambulance operations require a large amount of funds obtained from APBD funds through tariffs that were passed through the DKI Jakarta Governor Regulation five years ago. For this reason, a new tariff is required to adjust to current conditions. Objectives: The purpose of this study is to calculate the unit cost of ambulance services in DKI Jakarta to be a consideration in the tariff setting policy in DKI Jakarta province. Research Metodes: This study uses a quantitative descriptive approach to obtain information about the unit cost of the Jakarta ambulance production unit. The method used is the calculation of real cost using the basis of the causes of costs. This research was conducted at the DKI Jakarta Emergency Ambulance using secondary data on investment costs, operational costs and maintenance costs in 2018. Results: The total cost of emergency ambulance in 2018 is known that the proportion of three cost components, namely operational costs, is 76%, followed by investment costs of 20% and maintenance costs of 3%. The calculation of the total cost of medical evacuation using the double distribution method is Rp. 98,915,016,805.00 divided by the number of medical evacuations in 2018 of 37,564 activities, the unit cost of medical evacuation for the AGD of DKI Jakarta Health Office is Rp. 2,633,215.00 without subsidies. APBD costs, while if the subsidy component is included in the calculation, the unit cost for one trip to the AGD of the Health Office is Rp. 604,071.00. This is still far above the current tariff of Rp. 450.00, so the cost recovery rate (CRR) is still below. 100%. Conclusion: From the three cost components consisting of investment, operational and maintenance costs,the largest proportion was operational costs at 76%. The Cost Recovery Rate has not reached 100% so that the existing rates have not covered the costs incurred.   Keywords: ambulance; price fixing; unit cost

Sign in / Sign up

Export Citation Format

Share Document