scholarly journals Comparison of two methodologies for detection of Giardia spp. cysts and Cryptosporidium spp. oocysts in activated sludge samples from a sewage treatment plant in the city of Campinas, São Paulo State, Brazil

2007 ◽  
Vol 5 (4) ◽  
pp. 609-614 ◽  
Author(s):  
Taís Rondello Bonatti ◽  
Regina Maura Bueno Franco ◽  
Romeu Cantusio Neto
Keyword(s):  
Activated Sludge ◽  
Gastrointestinal Disease ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Cryptosporidium Spp ◽  
Two Samples ◽  
Cryptosporidium Oocysts ◽  
Increasing Trend ◽  
The City

Giardia spp. and Cryptosporidium spp. are recognized worldwide as highly infectious protozoan parasites that can cause severe gastrointestinal disease in humans and animals. The detection of these pathogens in activated sludge samples becomes interesting since there is an increasing trend for the use of sewage sludge (biosolids) in agriculture. A total of 22 samples were collected and evaluated by means of Centrifugal – Concentration, followed or not followed by a purification process (ether clarification and sucrose flotation). Student t tests for comparison of the two procedures indicated a higher recovery rate of Giardia cysts with Centrifugal – Concentration; with regard to Cryptosporidium oocysts, no significant differences were found between the two methods, as only two samples were positive. The Centrifugal – Concentration procedure was shown to be the simplest and cheapest to perform, as emphasized by the efficiency recovery results.

scholarly journals Occurrence of Giardia cysts and Cryptosporidium oocysts in activated sludge samples in Campinas, SP, Brazil

2004 ◽  
Vol 46 (6) ◽  
pp. 309-313 ◽  
Author(s):  
Luciana Urbano Santos ◽  
Taís Rondello Bonatti ◽  
Romeu Cantusio Neto ◽  
Regina Maura Bueno Franco
Keyword(s):  
Activated Sludge ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
High Concentration ◽  
Potential Source ◽  
Two Samples ◽  
Cryptosporidium Oocysts ◽  
Flotation Method ◽  
Giardia Cysts

Giardia and Cryptosporidium have caused several outbreaks of gastroenteritis in humans associated with drinking water. Contaminated sewage effluents are recognized as a potential source of waterborne protozoa. Due to the lack of studies about the occurrence of these parasites in sewage samples in Brazil, we compared the efficiency of two procedures for concentrating cysts and oocysts in activated sludge samples of one sewage treatment plant. For this, the samples were submitted to i) concentration by the ether clarification procedure (ECP) and to ii) purification by sucrose flotation method (SFM) and aliquots of the pellets were examined by immunofluorescence. Giardia cysts were present in all samples (100.0%; n = 8) when using ECP and kit 1 reagents, while kit 2 resulted in six positive samples (85.7%; n = 7). As for SFM, cysts were detected in 75.0% and 100.0% of these samples (for kit 1 and 2, respectively). Regarding Cryptosporidium, two samples (25.0%; kit 1 and 28.5% for kit 2) were detected positive by using ECP, while for SFM, only one sample (examined by kit 1) was positive (12.5%). The results of the control trial revealed Giardia and Cryptosporidium recovery efficiency rates for ECP of 54.5% and 9.6%, while SFM was 10.5% and 3.2%, respectively. Considering the high concentration detected, a previous evaluation of the activated sludge before its application in agriculture is recommended and with some improvement, ECP would be an appropriate simple technique for protozoa detection in sewage samples.

scholarly journals The Microbiota and Abundance of the Class 1 Integron-Integrase Gene in Tropical Sewage Treatment Plant Influent and Activated Sludge

PLoS ONE ◽  
2015 ◽  
Vol 10 (6) ◽  
pp. e0131532 ◽  
Author(s):  
Magna C. Paiva ◽  
Marcelo P. Ávila ◽  
Mariana P. Reis ◽  
Patrícia S. Costa ◽  
Regina M. D. Nardi ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Class 1 Integron ◽  
Integrase Gene ◽  
Class 1

Protesting the “Perfect City”

Memory Lands ◽  
2018 ◽  
Author(s):  
Christine M. DeLucia
Keyword(s):  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
King Philip's War ◽  
Urban Indians ◽  
Tribal Communities ◽  
Dugout Canoes ◽  
Social Opportunities ◽  
Indigenous Perspectives ◽  
The City

This chapter follows Native and Euro-American communities in eastern Massachusetts through the twentieth and twenty-first centuries, examining a series of commemorations and counterprotests that unfolded in urbanizing areas and related sites. It analyzes how Bostonians’ conceptions of the city and modernity tended to exclude Native peoples from both, instead relegating them to the past—despite the presence of numerous “Urban Indians” in the growing metropolis, who were seeking employment and social opportunities. It considers a series of pageants and historical markers erected across the Commonwealth, as well as Native pushback against dominant Euro-American narratives about history, such as a 1970 gathering in Patuxet/Plymouth, Massachusetts that foregrounded Indigenous perspectives and inaugurated an annual National Day of Mourning. The chapter also details how tribal communities challenged plans to build a sewage treatment plant on Deer Island, on grounds considered intensely sensitive for their ties to the incarcerations of King Philip’s War. Finally, it illuminates a recent series of memorial journeys along the Charles River and Boston Harbor Islands in which mishoonash (Native dugout canoes) have played important roles in reconnecting Native descendants to the landscapes of ancestors, as well as providing avenues for Indigenous solidarities into the future.

Thermochemical pretreatment in the anaerobic digestion of waste activated sludge

2002 ◽  
Vol 46 (10) ◽  
pp. 173-179 ◽  
Author(s):  
S. Tanaka ◽  
K. Kamiyama
Keyword(s):  
Anaerobic Digestion ◽  
Activated Sludge ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Municipal Sewage ◽  
Waste Activated Sludge ◽  
Anaerobic Digesters ◽  
Thermochemical Pretreatment ◽  
Methane Production Rate

Effects of a thermochemical pretreatment on the anaerobic digestion of waste activated sludge (WAS) was investigated by semicontinuously-fed digesters operated at 37¡C. WAS from a return sludge line of a municipal sewage treatment plant was pretreated by autoclaving at 130°C for 5 minutes after adding 0.3g NaOH/g VSS. Solids of WAS were thermochemically solubilized to one half and then 60% or more were in totality solubilized in anaerobic digesters fed with pretreated WAS at 2-8 days of hydraulic retention times (HRT), while only 16-36% were solubilized in digesters fed with raw WAS. The adverse effect of the set temperature (130°C) on the biodegradability of protein was not found. As a result, removal rates of COD in digestion was increased from 38% to 57% at 8 days HRT by the pretreatment. A specific methane production rate in the pretreated process was three times as high as the normal process. The thermochemical pretreatment was found to be very effective to enhance biodegradability as well as solubilization of WAS in anaerobic digestion.

The Infuence of the Depth of the Secondary Sedimentation Tanks on the Sedimentation Efficiency at Bromma Sewage Treatment Plant

1988 ◽  
Vol 20 (4-5) ◽  
pp. 143-152 ◽  
Author(s):  
M. Tendaj-Xavier ◽  
J. Hultgren
Keyword(s):  
Activated Sludge ◽  
Suspended Solids ◽  
Ferrous Sulphate ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Design Flow ◽  
Activated Sludge Process ◽  
Solids Concentration ◽  
Rapid Flow

Bromma sewage treatment plant is the second largest plant in Stockholm with a design flow of 160,000 m3/d. The wastewater is treated mechanically, chemically by pre-precipitation with ferrous sulphate, and biologically by the activated sludge process. The requirements for the plant are 8 mg BOD7/l, 0.4 mg P/l and 2 mg NH4+-N/l. The requirement for ammonia refers to the period July-October. In order to meet those rather stringent requirements, the biological step was expanded 3 years ago with 6 new sedimentation tanks. The 6 new tanks have the same area as the 6 old ones but they have only a depth of 3.7 m compared with the depth of the old tanks, 5.7 m. Experience from the first years of operation of the new tanks is that these tanks are more sensitive and less efficient than the older ones. It seems that the effluent suspended solids concentration from the old tanks is less influenced by rapid flow variations than the concentration in the effluent from the new secondary sedimentation tanks. During the nitrification period denitrification takes place to some degree in the secondary sedimentation tanks. This may cause loss of solids and it has been observed that the deeper old tanks usually produce an effluent of better quality and seem to be less influenced by denitrification than the new ones.

Study on Activated Sludge Microorganisms of Northern Winter Sewage Treatment Plant

2013 ◽  
Vol 361-363 ◽  
pp. 1032-1035
Author(s):  
Xi Tian ◽  
Sheng Shu Ai ◽  
Yan Zuo ◽  
Qing Kai Ren ◽  
Zhong Yan Xie
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Activated Sludge ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Sharp Edge ◽  
Northern Winter ◽  
Autumn And Winter ◽  
Scanning Electron

At the sewage temperatures of 7-15°C, it used biological video microscopy and scanning electron microscopy to detect activated sludge morphology, miniature animals and flora species in northern winter sewage treatment plant. The results showed that activated sludge had dense floc with sharp edge, and was bigger at the temperatures of 13 and 15°C than at the temperatures of 7, 9 and 11°C. When the autumn and winter seasons were alternate and the sewage temperature was instability, the edge of the floc was slightly fuzzy and there was a small amount of free bacteria in activated sludge floc. The study had also shown that the temperature was higher, the type of sludge miniature animal and flora species were richer.

The Research of Biological Method Degradation on Cooking Fume

2012 ◽  
Vol 573-574 ◽  
pp. 1106-1111
Author(s):  
Wen Wan Meng ◽  
Lei Liao ◽  
Fei Chao Zhao ◽  
Zhen Zhou Wei
Keyword(s):  
Activated Sludge ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Oxidation Ditch ◽  
Whole Process ◽  
Cooking Fumes ◽  
Cooking Fume ◽  
Oil Concentration ◽  
Degradation Ability

Experiments according to the current domestic situation of bio-treatment cooking fume, domesticated the activated sludge which taken from the oxidation ditch of the sewage treatment plant by using the simulated cooking fumes, discussed the concentration and morphology variation of activated sludge, researched the degradation ability of microorganism on cooking fume, the change of bacteria amount were studied in the whole process. Research showed that the sludge concentration decreased to 2878mg/L when the acclimatization time reached 50days; outlet and inlet oil concentration were consistent when the acclimatization time reached 30days while liquid fume concentration decreased to 8.436mg/L, the degradation rate of activated sludge on liquid fume was about 75% after 30 days; Microbial biomass increased first and then down become stable finally.

A Certain City Public Building Energy Consumption and Energy Saving of Economic Research and Statistics

2012 ◽  
Vol 512-515 ◽  
pp. 2842-2847
Author(s):  
Wei Yu ◽  
Wei Teng Li ◽  
Mei Juan Huo
Keyword(s):  
Economic Analysis ◽  
Statistical Power ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Economic Research ◽  
Pump System ◽  
Heat Pump System ◽  
Site Monitoring ◽  
The City

In this paper, the main public buildings, Lang fang City, Hebei province, the research summary and statistical power to the city building a sewage treatment plant sewage source heat pump system operating on-site monitoring, the monitoring results of economic analysis with traditional heating methods from the initial investment and operation of both comprehensive economic analysis and comparison.

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