Characteristics of WWTP sludge after drying in greenhouse for agricultural purposes

2012 ◽  
Vol 66 (7) ◽  
pp. 1460-1466 ◽  
Author(s):  
Márcia Regina Pereira Lima ◽  
Eliana Zandonade ◽  
Pedro Alem Sobrinho
Keyword(s):  
Sewage Treatment ◽  
Wastewater Sludge ◽  
Metropolitan Region ◽  
Solar Drying ◽  
Drying Process ◽  
Sewage Treatment Plants ◽  
Inorganic Substances ◽  
Regulatory Standards ◽  
Volatile Solids ◽  
Physical Layout

The sludge generated by sewage treatment which meets regulatory standards can be used in agriculture. With this understanding, the focus of this study is the evaluation of the agricultural characteristics and inorganic substances in excess activated sludge, which was subjected to drying in a greenhouse. The variables (factor) evaluated during the drying process were: type of sludge (digested or not digested), addition of lime to the sludge, and the physical layout and rotation of sludge in the greenhouse. The parameters monitored for this assessment were moisture, volatile solids and pH. The greenhouse cover and sides were made of translucent plastic to allow the penetration of solar radiation and prevent water from entering. A impermeable floor was used. The sludge was generated in sewage treatment plants located in the metropolitan region of Grande Vitória, Espírito Santo, Brazil. The solar drying of wastewater sludge in a greenhouse presented satisfactory results.

Destruction of Faecal Bacteria, Enteroviruses and OVA of Parasites in Wastewater Sludge by Aerobic Thermophilic and Anaerobic Mesophilic Digestion

1991 ◽  
Vol 24 (2) ◽  
pp. 377-380 ◽  
Author(s):  
E. G. Carrington ◽  
E. B. Pike ◽  
D. Auty ◽  
R. Morris
Keyword(s):  
Sewage Treatment ◽  
Treatment Plant ◽  
Wastewater Sludge ◽  
Sludge Treatment ◽  
Volatile Solids ◽  
Working Volume ◽  
Thermotolerant Coliforms ◽  
Mesophilic Digestion ◽  
Faecal Bacteria ◽  
Faecal Streptococci

A new sludge treatment plant at Harrogate South Sewage Treatment Works is designed to handle up to 4 tonnes (dry solids) daily. Sludge is thickened continuously up to 8% (ds) and is then treated in parallel anaerobic mesophilic (AD) and thermophilic aerobic digestion (TAD) plants each with a maximum working volume of 530m3. Microbiological studies were carried out to compare the destruction of pathogens and faecal indicator bacteria. The AD plant operated with a mean retention of 26 days at 34 °C and achieved 49% reduction of volatile solids. The TAD plant operated with a mean retention of 28 days at 55 °C and reduced volatile solids by 35%. Operation was on a pump in-pump out cycle, guaranteeing 4h retention for all sludge. The disinfecting ability of TAD exceeded that of AD since it reduced counts of Enterobacteriaceae, thermotolerant coliforms and faecal streptococci to below 103/100ml, rendered cytopathic enteroviruses undetectable and destroyed viability of Ascaris suum ova within 4h. The AD process reduced bacterial counts by 90% and enteroviruses by 99%, but has no effect upon viability of Ascaris ova.

The Location of Sewage Treatment Plants on a Continuous Space: Theoretical and Empirical Analyses

1983 ◽  
Vol 15 (9) ◽  
pp. 1205-1217 ◽  
Author(s):  
Y Kitabatake ◽  
T Miyazaki
Keyword(s):  
Location Problem ◽  
Population Distribution ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Plant Location ◽  
Metropolitan Region ◽  
Continuous Space ◽  
Sewage Treatment Plants ◽  
One Dimensional

A theoretical model of the sewage treatment plant location problem is presented, based on the assumptions of a homogeneous space and a homogeneous channel geometry of a river running parallel to a one-dimensional region. The analytical structure of the model is discussed. The model is then applied to the specific case of a suburban region of the Tokyo Metropolitan Region, where both the homogeneity assumptions are dropped. The numerical simulations show clearly how the heterogeneity in population distribution and river characteristics, as well as the trade-off ratio between water quality and least cost expenditure, affects the optimal plant locations.

scholarly journals Cumulative ventilation air drying potential as an indication of dry mass content in wastewater sludge in a thin-layer solar drying facility

2013 ◽  
Vol 34 (4) ◽  
pp. 23-34 ◽  
Author(s):  
Piotr Krawczyk
Keyword(s):  
Sewage Sludge ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Dry Mass ◽  
Wastewater Sludge ◽  
Solar Drying ◽  
Mass Content ◽  
Large Variability ◽  
Low Temperature Drying

Abstract Controlling low-temperature drying facilities which utilise nonprepared air is quite difficult, due to very large variability of ventilation air parameters - both in daily and seasonal cycles. The paper defines the concept of cumulative drying potential of ventilation air and presents experimental evidence that there is a relation between this parameter and condition of the dried matter (sewage sludge). Knowledge on current dry mass content in the dried matter (sewage sludge) provides new possibilities for controlling such systems. Experimental data analysed in the paper was collected in early 2012 during operation of a test solar drying facility in a sewage treatment plant in Błonie near Warsaw, Poland.

Current and planned disposal of sewage sludge and other waste products from the ruhrverband wastewater treatment

1996 ◽  
Vol 33 (12) ◽  
pp. 219-228 ◽  
Author(s):  
Harro Bode ◽  
Klaus R. Imhoff
Keyword(s):  
Wastewater Treatment ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Dry Mass ◽  
Legal Framework ◽  
Waste Products ◽  
Sewage Treatment Plants ◽  
Volatile Solids ◽  
Technical Solutions

From the year 2005 onwards German waste disposal regulations prevent the disposal of residual wastes from sewage treatment plants in landfills if the waste contains more than 5% volatile solids by dry mass. As a result of this requirement the Ruhrverband, one of Germany's largest sewage treatment plant operators, needs to change its disposal methods to a certain extent. This paper describes the present ways to dispose of sludge as well as of screenings and grit. After that it outlines the concept for future disposal. Besides the legal framework the technical solutions for the different disposal problems are described and their costs are given.

Plasticizers and related toxic degradation products in wastewater sludges

2008 ◽  
Vol 57 (3) ◽  
pp. 367-374 ◽  
Author(s):  
I. Beauchesne ◽  
S. Barnabé ◽  
D. G. Cooper ◽  
J. A. Nicell
Keyword(s):  
Degradation Products ◽  
Sewage Treatment ◽  
Drying Process ◽  
Sewage Treatment Plants ◽  
Toxic Metabolites ◽  
Beneficial Uses ◽  
Pure Cultures ◽  
Almost All ◽  
Ethylhexyl Phthalate ◽  
Wastewater Sludges

Plasticizers can persist during the treatment of wastewaters in sewage treatment plants (STPs) and can be discharged in effluents and/or accumulated in sewage sludges. For example, di-2-ethylhexyl phthalate (DEHP) is a common plasticizer that is now considered a priority pollutant and is known to accumulate in sludges. This may add constraints to the exploitation of the beneficial uses of sludges that contain significant quantities of plasticizers. Recently, it was demonstrated in studies with pure cultures that the biodegradation of plasticizers including DEHP and di-ethylhexyl adipate (DEHA) generates toxic metabolites including 2-ethylhexanoic acid, 2-ethylhexanol, and 2-ethylhexanal. However, the environmental impacts and fate of the degradation products arising from plasticizers are unknown. Therefore, this work investigated the concentrations of DEHP and DEHA and their metabolites in the sludges from several STPs in Quebec, Canada. DEHP and DEHA were found in concentrations ranging from 15 to 346 mg kg−1 and 4 to 743 mg kg−1, respectively, in primary, secondary, digested, dewatered or dried sludges. Metabolites were detected in almost all sludges, except those that had undergone a drying process at high temperature. It is concluded that sludges can represent significant sources of plasticizers and their toxic metabolites in the environment.

Changes of microbial indices of water quality in the Vistula and Brda rivers as a result of sewage treatment plant operation

2008 ◽  
Vol 37 (2) ◽  
Author(s):  
Maciej Walczak
Keyword(s):  
Water Quality ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Sewage Treatment Plants ◽  
Plant Operation ◽  
Treated Sewage ◽  
Microbiological Parameters ◽  
Microbial Indices

Changes of microbial indices of water quality in the Vistula and Brda rivers as a result of sewage treatment plant operationThis paper reports the results of studies of microbiological changes in the water quality of the Vistula and Brda rivers after the opening of sewage treatment plants in Bydgoszcz. The study involved determining the microbiological parameters of water quality. Based on the results obtained, it was found that the quality of the water in both rivers had improved decidedly after the opening of the plants, although an increased number of individual groups of microorganisms was found at the treated sewage outlet from one of the plants.

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.

Activated Sludge Exocellular Material Extraction Methods and Problems

1974 ◽  
Vol 9 (1) ◽  
pp. 250-261
Author(s):  
D.F. Carr ◽  
J. Ganczarczyk
Keyword(s):  
Activated Sludge ◽  
High Speed ◽  
Sewage Treatment ◽  
Dry Weight ◽  
Extraction Methods ◽  
Volatile Material ◽  
Bacterial Cultures ◽  
Volatile Solids ◽  
Pure Bacterial Cultures ◽  
Material Extraction

Abstract Activated sludge samples from two Toronto sewage treatment plants were subjected to the extraction of exocellular material by means of 9 different methods suggested for this purpose. Some of those methods, originally developed for pure bacterial cultures, were modified for the application to activated sludge. The amount of exocellular material obtained varied for Lakeview sludges from 0.4 to 3.2% of their dry volatile solids, and for Humber sludges from 0.3 to 5.3%. It has been found that extractions by the use of sulphuric acid, high-speed centrifugation and sodium hydroxide, were not suitable for the studied material. Especially surprising was the ineffectiveness of high-speed centrifugation to yield any measurable amounts of extract. The boiling water extraction is recommended for further studies on activated sludge exocellular material. The material extracted from activated sludge is very complex in nature. Generally more polysaccharide than protein was extracted, but the remaining volatile material may form up to 70% of the dry weight.

Presence of Phenolic Compounds in Sewage, Effluent and Sludge from Municipal Sewage Treatment Plants

1982 ◽  
Vol 14 (4-5) ◽  
pp. 143-150 ◽  
Author(s):  
F B DeWalle ◽  
D A Kalman ◽  
R Dills ◽  
D Norman ◽  
E S K Chian ◽  
...  
Keyword(s):  
Sewage Treatment ◽  
Municipal Sewage ◽  
Sewage Effluent ◽  
Capillary Gc ◽  
Digested Sludge ◽  
Calculated Concentration ◽  
Sewage Treatment Plants ◽  
Anaerobically Digested Sludge ◽  
Final Effluent ◽  
Dimethyl Phenol

A total of 25 municipal sewage treatment plants were sampled, 10 of which were resampled, to determine the quantity of phenolics in the sewage, final effluent and the anaerobically digested sludge using capillary GC/MS/DS/techniques. The study noted in decreasing order of frequency in raw sewage: phenol, pentachloro-phenol, dimethyl phenol, 3-methyl, 4-chlorophenol, 2,4,6-trichloro-phenol, 2,4-dichlorophenol, 2-nitrophenol, 2-chlorophenol, 2,4-dinitro-6-methylphenol and 2,4-dinitrophenol. The maximum concentration of phenol in sewage and sludge was 2800 ppb and 4460 respectively, while similar values for pentachlorophenol were 58 and 1200 ppb. Statistically calculated concentration reductions for phenol and dimethyl phenol were generally greater than noted for tri- and pentachlorophenol. Low decreases or increases were noted for monochlorophenol and especially for dichlorophenol as a result of the chloronation of the final effluent.

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