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

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.

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.

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.

The Transformation of Heavy Metal Be in Activated Sludge Process

2012 ◽  
Vol 178-181 ◽  
pp. 633-636 ◽  
Author(s):  
Feng Chen ◽  
Xiu Lian Zhu ◽  
Wei Yu
Keyword(s):  
Heavy Metal ◽  
Activated Sludge ◽  
Sewage Treatment ◽  
Great Influence ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Urban Land Use ◽  
Huge Number ◽  
Sludge Treatment

Municipalsludge is refers to the product of sewage treatment plant, facing the huge number of municipalsludge, the disposal of the municipalsludge has aroused wide attention of all countries. Many studies consider that urban land use of the municipalsludge is the most effective method, However heavy metal accumulats in the sludge and the environment of the risk with agricultural appears day after day.The purpose of this study is: analysis the transfermation of heavy metals in the activated sludge system of various structures. put forward the solution of reducing heavy metal exceeded in the activated sludge treatment process.It appears that the coagulation can make colloid stabilized and sedimentation, can control the input of the heavy metal effectively; Adsorption of activated sludge to heavy metal is very fast, in 30 min basic reached adsorption balance, probably 80% or more;The change from oxygen to aerobic have great influence on Heavy metal biological adsorption;An aerobic digestion processes can reduce the volume and quality of sludge, but there is no enrichment role to heavy metal in sludge.

scholarly journals Reliability of removal of selected pollutants in different technological solutions of household wastewater treatment plants

2017 ◽  
Vol 35 (1) ◽  
pp. 141-148 ◽  
Author(s):  
Michał Marzec
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Suspended Solids ◽  
Wastewater Treatment Plants ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Total Suspended Solids ◽  
Hybrid Reactor ◽  
Limit Values

AbstractThe reliability of removal of selected contaminants in three technological solutions of the household sewage treatment plants was analysed in this paper. The reliability of the sewage treatment plant with activated sludge, sprinkled biological deposit and hybrid reactor (activated sludge and immersed trickling filter) was analyzed. The analysis was performed using the Weibull method for basic indicators of impurities, BOD5, COD and total suspended solids. The technological reliability of the active sludge treatment plant was 70% for BOD5, 87% for COD and 66% for total suspended solids. In the sewage treatment plant with a biological deposit, the reliability values determined were: 30% (BOD5), 60% (COD) and 67% (total suspended solids). In a treatment plant with a hybrid reactor, 30% of the BOD5and COD limit values were exceeded, while 30% of the total suspended solids were exceeded. The reliability levels are significantly lower than the acceptable levels proposed in the literature, which means that the wastewater discharged from the analysed wastewater treatment plants often exceeds the limit values of indicators specified in currently valid in Poland Regulation of the Minister of Environment for object to 2000 population equivalent.

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