Study of Continuos Settling Vessels Operating with Suspensions Previously Floculated

2008 ◽  
Vol 591-593 ◽  
pp. 358-361
Author(s):  
J.F. Nunes ◽  
J.R. Lira ◽  
João Jorge Ribeiro Damasceno
Keyword(s):  
Wastewater Treatment ◽  
Solid Particle ◽  
Aluminum Sulfate ◽  
Cylindrical Part ◽  
Continuous Operation ◽  
Circular Section ◽  
Operational Conditions ◽  
The Stability ◽  
Solid Liquid ◽  
Solid Liquid Separation

The settling vessels are equipment destined to solid-liquid separation; usually have continuous operation, with a circular section, presenting one conic and one cylindrical part. They are very used in chemical industries: wastewater treatment, minerals industries; to concentrate or to remove the solids. The solid particle splitting with small granular becomes difficult through the operation of conventional sedimentation. An expedient very used in the industry is the flocculant substance addition, whose objective is to promote the precipitation of particles, with decantation speed is upper than the single one. The present work aim the study of the burst operational conditions that influence the formation and the stability of these aggregates, the flake, the effect of pH and the concentration of flocculant using kaolin suspension and genfloc, that contains aluminum sulfate, as a flocculant; and the capacity of conventional settling vessel, which area of the transversal remains constant, considering this operational conditions.

Microscopic and enzymatic investigations on biofilms of wastewater treatment systems

1997 ◽  
Vol 36 (1) ◽  
pp. 21-30 ◽  
Author(s):  
Tanja Gschlößl ◽  
Ingrid Michel ◽  
Marion Heiter ◽  
Christian Nerger ◽  
Verena Rehbein
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Biological Properties ◽  
Organic Substances ◽  
Operational Conditions ◽  
Sludge Flocs ◽  
And Performance ◽  
The Stability

In biological wastewater treatment inorganic and organic substances are fixed and metabolized by mixed populations of microorganisms forming either activated sludge flocs or biofilms. Not only the type of wastewater but also the operational conditions promote the development of an adapted biocenosis of microorganisms with specialized enzymatic functions. Understanding the biological properties of the microorganisms, it is possible to assess the prevailing conditions in their natural environment. Regular microscopic and enzymatic investigations of activated sludge and biofilms thus improve the assessment of the stability of the processes and support troubleshooting in wastewater treatment plants. While the role of bacteria is often discussed, the importance of ciliated protozoes and metazoes for the maintenance of the stability of biofilm systems is rarely mentioned. In this paper we intend to show some new results of direct microscopic observations in different sorts of biofilm systems focussing upon ciliated protozoes and metazoes. Practical results will demonstrate the relation between enzymatic analysis, microscopic investigations and performance of biofilm systems.

Effect of C/N ratio on nitrous oxide emission from swine wastewater treatment process

2004 ◽  
Vol 49 (5-6) ◽  
pp. 359-371 ◽  
Author(s):  
N. Kishida ◽  
J.H. Kim ◽  
Y. Kimochi ◽  
O. Nishimura ◽  
H. Sasaki ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Wastewater Treatment ◽  
Treatment Process ◽  
N2o Emission ◽  
Swine Wastewater ◽  
N2o Emissions ◽  
Wastewater Treatment Process ◽  
Phase Study ◽  
Solid Liquid ◽  
Solid Liquid Separation

To evaluate control parameters for nitrous oxide (N2O) emissions in the swine wastewater treatment process, the N2O emission was compared in the activated sludge from SBRs acclimated in different carbon/nitrogen (C/N) ratios. N2O emission from a denitrification phase was very strongly dependent on C/N ratio of swine wastewater, and the total N2O emission in the operating condition of BOD5/TN ratio of 2.6 was approximately 270 times greater than that in BOD5/TN ratio of 4.5. However, the effect of C/N ratio on N2O emission amount from nitrification was not significant in an oxic phase study. It is considered that stabilization of the C/N ratio through optimal solid-liquid separation of slurry or use of an external carbon source is indispensable for effective N2O emission control from nitrogen removal process of swine wastewater.

Household Membrane Bioreactor in Domestic Wastewater Treatment

1993 ◽  
Vol 27 (1) ◽  
pp. 171-178 ◽  
Author(s):  
C. Chiemchaisri ◽  
K. Yamamoto ◽  
S. Vigneswaran
Keyword(s):  
Wastewater Treatment ◽  
Hollow Fiber Membrane ◽  
Domestic Wastewater ◽  
Pilot Scale ◽  
Experimental Unit ◽  
Transmembrane Pressure ◽  
Working Volume ◽  
Operational Life ◽  
Solid Liquid ◽  
Solid Liquid Separation

The activated sludge process coupled with hollow fiber membrane for solid-liquid separation was applied to treat low strength domestic wastewater. Pilot-scale experimental unit used in this study consisted of 2 modules of 0.03 μm pore size with 9 m2 surface area each, immersed in the reactor which has a maximum working volume of 1.5 m3. Even when sewage was fed at varying rates following its diurnal flow variation to the bioreactor, good stability of the process was achieved which was shown by the consistency in treated water quality. The effluent turbidity and COD were well within the limits (less than 0.5 NTU and 3-5 mg/L). The transmembrane pressure drop was less than 20 cm Hg even after 2 months of operation. Application of jet aeration could be used to prolong the operational life of the membrane in the bioreactor. This system is an ideal one to be used as household wastewater treatment system.

Filtration on Hydrocyclone of Optimized Geometric Relationships

2008 ◽  
Vol 591-593 ◽  
pp. 341-346 ◽  
Author(s):  
Luiz Gustavo Martins Vieira ◽  
João Jorge Ribeiro Damasceno ◽  
Marcos A.S. Barrozo
Keyword(s):  
Fluid Dynamics ◽  
Chemical Engineering ◽  
Euler Number ◽  
Experimental Studies ◽  
Total Efficiency ◽  
Separation Device ◽  
Operational Conditions ◽  
Conical Section ◽  
Solid Liquid ◽  
Solid Liquid Separation

The filtering hydrocyclone is a solid-liquid separation device patented by the Chemical Engineering School of the Federal University of Uberlândia, which consists of a hydrocyclone whose conical section was replaced by a conical filtering wall. During the operation of these separators, besides underflow and overflow streams, the existence of a filtrate stream generated by the filtering process is found in the permeable conical region of the hydrocyclones. Vieira et al. (2006) got a filtering hydrocyclone that simultaneously presented low Euler Number and cut size diameter because its geometric relationships has been optimized. The objective of this work was to analyze the behavior of this optimized filtering hydrocyclone through computational fluid dynamics and experimental studies. In the same operational conditions of the conventional hydrocyclone, the performance of this optimized filtering hydrocyclone was significantly influenced by the filtration. The filtration caused decreases in the Euler number and increment in the total efficiency.

The Applications of MBR in Municipal Wastewater Treatment and Reuse

2013 ◽  
Vol 295-298 ◽  
pp. 1045-1048 ◽  
Author(s):  
Jian Li ◽  
Yun Long Yang ◽  
Kai Xue
Keyword(s):  
Wastewater Treatment ◽  
Membrane Filtration ◽  
Membrane Bioreactor ◽  
Municipal Wastewater ◽  
Municipal Wastewater Treatment ◽  
Recycled Water ◽  
High Concentration ◽  
Combination Technology ◽  
Solid Liquid ◽  
Solid Liquid Separation

The membrane-bioreactor (MBR) is a combination technology that includes biological treatment and membrane filtration separation. According to the test, it studied the use of membrane bioreactor reuse in municipal wastewater treatment and reuse. The test measured every target about treated water quality,NH3-N,TN,CODcr,Sludge concentration and Turbidity. The results of the test show that the MBR can get efficient solid liquid separation to obtain the recycled water directly, and can maintain high concentration of microbial biomass in bioreactor. In addition, it can increase the volume of load handing equipment, and reduce floor space.

The role of innovative technologies in achieving energy-neutral wastewater treatment

2016 ◽  
Vol 11 (4) ◽  
pp. 691-701 ◽  
Author(s):  
J. Peeters ◽  
G. Vicevic ◽  
G. H. Koops ◽  
P. Côté
Keyword(s):  
Wastewater Treatment ◽  
Hollow Fiber ◽  
Membrane Filtration ◽  
Electricity Consumption ◽  
Biofilm Reactor ◽  
Filtration Membranes ◽  
Conventional Activated Sludge ◽  
New Energy ◽  
Solid Liquid ◽  
Solid Liquid Separation

A new flowsheet is proposed to achieve energy-neutral wastewater treatment (even better, electricity-neutral) while removing nitrogen using the proven nitrification-denitrification metabolic pathway. It is compatible with solid-liquid separation by conventional clarification or membrane filtration. The new flowsheet is based on a hybrid membrane-aerated biofilm reactor process which uses hollow fiber membranes arranged in modules and cassettes deployed in a way similar to immersed hollow fiber filtration membranes used for MBR (e.g., the ZeeWeed1 500 product). Atmospheric air is fed down the lumen of hollow fibers and oxygen is transferred to the biofilm growing on the outer surface of the membrane without the formation of bubbles. The new energy-neutral flowsheet is compared to a conventional activated sludge (CAS) flowsheet including complete wastewater and sludge treatment with anaerobic digestion and combined heat and power energy recovery. The new flowsheet has an electricity consumption 40% lower and energy production 18% higher as compared to the CAS flowsheet and is overall electricity-neutral.

Membrane bioreactor with nonwoven fabrics as solid–liquid separation media for wastewater treatment

Desalination ◽  
2007 ◽  
Vol 202 (1-3) ◽  
pp. 122-128 ◽  
Author(s):  
Wang-Kuan Chang ◽  
Alvin Yen-Jung Hu ◽  
Ren-Yang Horng ◽  
Wen-Yuang Tzou
Keyword(s):  
Wastewater Treatment ◽  
Membrane Bioreactor ◽  
Liquid Separation ◽  
Nonwoven Fabrics ◽  
Separation Media ◽  
Solid Liquid ◽  
Solid Liquid Separation

Woven Fabric Bioreactor (WFBR) as the Filter Material for Wastewater Treatment

2011 ◽  
Vol 356-360 ◽  
pp. 1613-1617 ◽  
Author(s):  
Qi Yang ◽  
Zhen Hong Liu ◽  
Xia Sheng
Keyword(s):  
Wastewater Treatment ◽  
Membrane Filtration ◽  
Treatment Plant ◽  
Cost Effective ◽  
Filter Material ◽  
Membrane Bioreactors ◽  
Woven Fabric ◽  
Operational Conditions ◽  
Solids Retention ◽  
Solid Liquid

Conventional and modified membrane bioreactors (MBRs) are effective increasingly used in small sized wastewater treatment plant. However, their widespread applications are hindered by their elevated energy consumption and the high costs of investment for the membrane modules. In this study, we investigated a modified an improved MBR system that utilized a cost effective woven fabric instead of nonwoven as the filter material in MBR modules. The woven fabric bioreactor (WFBR) system was operated in a continuous mode at HRT from 33 to 12h. Under the operational conditions of BOD loading rates from 0.12 to 0.28 kg BOD/kg MLSS /d, the WFBR system was able to reduce up 93.57% COD. The 38μm woven fabric performed well in solid-liquid separator, with an average suspended solids retention of 99.47% at MLSS of 4710~9951 mg/L. The WFBR system eliminated suction pumping by using a gravity head in the membrane filtration of the effluent over the entire operational period of 60 d.

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