High rate treatment by aerobic upflow sludge blanket (AUSB) with external oxygenation

2004 ◽  
Vol 50 (8) ◽  
pp. 193-200 ◽  
Author(s):  
K.R. Sharma ◽  
J.C. Huang
Keyword(s):  
Biological Treatment ◽  
Biomass Concentration ◽  
Suspended Solid ◽  
High Rate ◽  
Flow Recirculation ◽  
Suspended Solid Concentration ◽  
Specific Oxygen Uptake Rate ◽  
Volumetric Loading ◽  
High Biomass Concentration ◽  
Very High

A 3-year study was conducted using an aerobic upflow sludge blanket (AUSB) reactor to achieve high-rate biological treatment through maintenance of a high biomass concentration (7–10 g VSS/L) together with a high oxygen flux. The AUSB reactor was not aerated directly; instead, oxygenation was provided in an external chamber with flow recirculation. The oxygenation was provided at four different ressurizations: 0, 15, 20 and 25 psig. The AUSB reactor was also pressurized to avoid the flotation of biomass. The flow recirculation rate was varied from 400% to 1,500% in order to ensure adequate oxygen supply. It was found that the AUSB system was able to handle a volumetric loading of as high as 10 kg COD/m3-day with a removal efficiency of 92%. Despite a high upflow velocity through AUSB, the effluent suspended solid concentration was mostly below 60 mg/L. The active fraction of biomass in the AUSB sludge was about 3 times higher than that of the regular activated sludge. This was indicated by a very high specific oxygen uptake rate (SOUR), up to 180-250 mg O2/g VSS-hr. The sludge yield in the entire system was only 0.09 to 0.13 g VSS/g COD removed. This was mainly caused by additional auto-oxidation of biosolids in the oxygenation chamber due to flow recirculation.

Sustainable sewage treatment plants - application of nanofiltration and ultrafiltration to a pressurized bioreactor

1996 ◽  
Vol 34 (3-4) ◽  
pp. 389-394 ◽  
Author(s):  
Kh. Krauth
Keyword(s):  
New Technology ◽  
Sewage Treatment ◽  
Biomass Concentration ◽  
Nanofiltration Membrane ◽  
Excess Sludge ◽  
Sewage Treatment Plants ◽  
The University ◽  
High Biomass Concentration ◽  
Very High

Based on earlier studies and experiences the Institute of Sanitary Engineering, Water Quality and Waste Management at the University of Stuttgart has developed a new technology to purify wastewater to a quality suitable for reuse as industrial water. This technology consists of a pressurized bioreactor under 3 bar with an ultrafiltration unit for sludge retention coupled with a nanofiltration unit. The concentrate retained in the nanofiltration is fed back to the bioreactor resulting in an enhanced biodegradability and a better quality of the effluent. The flux through the ultrafiltration membrane ranged from 100 to 200 l/(m3h); that through the nanofiltration membrane was around 0.05 l/(m3h). While attaining a very high biomass concentration (20 to 40 kg MLVSS/m3) in the bioreactor the excess sludge production is remarkably small with 0.7 to 1.0% of the influent COD.

Comparative study of oil accumulation characteristics in attached and suspended growth reactors

2000 ◽  
Vol 42 (1-2) ◽  
pp. 1-5 ◽  
Author(s):  
Y. Abadi ◽  
N. Galil
Keyword(s):  
Biomass Concentration ◽  
Suspended Solid ◽  
Settling Chamber ◽  
Oil Removal ◽  
Short Term ◽  
Oil Accumulation ◽  
Oil Sorption ◽  
Oil Fraction ◽  
Suspended Solid Concentration ◽  
Suspended Growth

In this study, the sorption extent and characteristics of low biodegradability hydrocarbons to biomass in attached growth (AG) and suspended growth (SG) processes were compared. Distinction was made between settled biomass from the settling chamber (sludge biomass) and non-settled biomass from the process effluent (effluent biomass). In both processes the sorption to the sludge biomass was the main oil removal mechanism, however, differences in the extent and characteristics of oil sorption were observed. The AG sludge biomass sorbed more oil than the SG sludge biomass and the sludge biomass oil fraction was always higher than the effluent biomass oil fraction. In the SG process, the sludge biomass oil fraction was lower than the effluent biomass oil fraction for the first 42 days of operation and then the trend reversed. The settling quality in the SG process was damaged during the sorption of oil and biomass concentration in the reactor decreased, while the AG process suffered only from short-term disturbances in the settling quality. Furthermore, the results indicated that effluent suspended solid concentration in the AG process decreased when the oil sorption rate was high.

scholarly journals Effect of magnetic field on biomass properties and their role in biodegradation under condition of low dissolved oxygen

2021 ◽  
Vol 11 (7) ◽  
Author(s):  
Nur Syamimi Zaidi ◽  
Johan Sohaili ◽  
Khalida Muda ◽  
Mika Sillanpää ◽  
Norelyza Hussein
Keyword(s):  
Magnetic Field ◽  
Dissolved Oxygen ◽  
Biomass Concentration ◽  
Aerobic Bacteria ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Great Chance ◽  
Sludge Bulking ◽  
The Magnetic Field ◽  
High Biomass Concentration

AbstractLow condition of dissolved oxygen (DO) is commonly associated with sludge bulking problem that was able to disrupt the efficiency of wastewater treatment performances. Relatively, very little attention was paid to the possibility of applying magnetic field in controlling the bulking problem. Hence, this study aims to investigate the performance of magnetic field on biomass properties and its effect on biodegradation under low condition of DO. Two continuous laboratory-scale sequencing batch reactors—Reactor A (SBRA) and Reactor B (SBRB)—were setup. SBRA was equipped with the magnetic device to exhibit magnetic field of 88 mT, while SBRB acted as a control system. The results showed that the biomass concentration in SBRA was higher compared to SBRB. High biomass concentration in SBRA resulted to better settleability with mean SVI of less than 30 mL/g. SBRA also showed consistently high removal performances of organic and inorganic contents compared to SBRB. These observations confirmed that the magnetic field was able to enhance the biomass properties, which further enhance the biodegradation ability of the aerobic bacteria under low DO condition. This also indicates that under the sludge bulking circumstances, the use of magnetic field stands a great chance in maintaining high biodegradation of the treatment system.

Modeling Mass Transfer in Biological Wastewater Treatment Processes

1986 ◽  
Vol 18 (6) ◽  
pp. 35-45 ◽  
Author(s):  
John C. Kissel
Keyword(s):  
Mass Transfer ◽  
Computer Simulation ◽  
Wastewater Treatment ◽  
Biological Treatment ◽  
Process Models ◽  
High Rate ◽  
Biological Wastewater Treatment ◽  
Trickling Filter ◽  
Treatment Processes ◽  
Individual Effects

Parameters characterizing intrasolid, liquid/solid, and gas/liquid mass transport phenomena in biological treatment systems are required if mass transfer is to be included in process models. Estimates of such parameters are presented and discussed. Collective and individual effects of mass transfer resistances are illustrated by computer simulation of a high-rate trickling filter.

scholarly journals EFICIÊNCIA DE DIFERENTES ELEMENTOS FILTRANTES NA PREVENÇÃO DE OBSTRUÇÃO DE GOTEJADORES

Irriga ◽  
2003 ◽  
Vol 8 (1) ◽  
pp. 78-87 ◽  
Author(s):  
José Euclides Stipp Paterniani ◽  
Marcos Eduardo Scatolini
Keyword(s):  
Irrigation Water ◽  
Suspended Solid ◽  
Filter Element ◽  
Solid Concentration ◽  
Algae Removal ◽  
Mesh Screen ◽  
Suspended Solid Concentration ◽  
E Mail ◽  
Synthetic Fabric ◽  
Continuous Average

EFICIÊNCIA DE DIFERENTES ELEMENTOS FILTRANTES NA PREVENÇÃO DE OBSTRUÇÃO DE GOTEJADORES   José Euclides Stipp Paterniani Marcos Eduardo ScatoliniFaculdade de Engenharia Agrícola, Universidade Estadual de Campinas, Campinas, SP. CP 6011, CEP 13083-970, E-mail: [email protected]   1 RESUMO  Durante ensaios para verificação de eficiência de retenção de algas em filtros de discos 120 MESH, tela 120 MESH e manta sintética não tecida, foram avaliados o grau de obstrução de gotejadores de labirinto com fluxo turbulento e vazão nominal de 4 L.h-1 e 8 L.h-1. Para determinação da obstrução causada por impurezas não retidas no meio filtrante foram avaliadas a evolução da vazão e da uniformidade estatística dos gotejadores submetidos aos diferentes meios filtrantes durante um período de 22 semanas durante 4 horas diárias e comparadas com uma parcela testemunha sem elemento filtrante. Os resultados mostraram que houve diferença significativa entre o elemento de discos, que apresentou maior uniformidade estatística, os filtros de manta e tela com valores intermediários e a testemunha que apresentou menor uniformidade estatística. No entanto, para caracterizar de maneira definida a diferença no desempenho dos elementos filtrantes, estes valores deveriam vir acompanhados de uma redução contínua na vazão média dos tratamentos, o que foi observado apenas para o elemento de tela com o gotejador de 4 L.h-1. As demais variações da uniformidade estatística foram temporais, provavelmente devido a obstruções  temporárias ocasionadas por variações da concentração de sólidos suspensos na água de irrigação.  UNITERMOS: Filtragem, Gotejamento, Qualidade da água.   PATERNIANI, J.E.S.; SCATOLINI, M.E. EFFICIENCY OF DIFFERENT FILTER ELEMENTS TO PREVENT TRICKLE CLOGGING   2 ABSTRACT  This work aimed to verify the efficiency of algae removal in disks 120 mesh, screen 120  mesh, and non woven synthetic fabric filters. It was evaluated the degree of clogging of turbulent flow drippers on 4 L.h-1 and 8 L.h-1 outflow. For blockage determination the outflow evolution  and statistics uniformity (Us) of the dripper have been evaluated when submitted to different filter media over 22 weeks, 4 daily hours compared to a control without the filter element. The results indicated significant differences among the elements. The disk element presented greater statistic uniformity. The screen filter and the non woven synthetic fabric element presented intermediate values whereas the parcel with no filter element (control) presented minor statistic uniformity. However, in order to characterize performance differences among them, values should be presented along with a  continuous average outflow reduction in all treatments. This pattern was observed only for the screen filter and 4 L.h-1 drippers. The statistics uniformity variation has been probably caused by temporary blockages due to variation in suspended solid concentration in irrigation water.  KEYWORDS: filtration, drip irrigation, water quality. 

Biology, Management, and Protection of North American Sturgeon

2002 ◽  
Keyword(s):  
Extinction Risk ◽  
High Rate ◽  
Future Research ◽  
Shortnose Sturgeon ◽  
Management Options ◽  
Connecticut River ◽  
Acipenser Brevirostrum ◽  
Survival And Reproduction ◽  
Very High ◽  
Existing Data

<em>Abstract.</em>—The shortnose sturgeon, <em>Acipenser brevirostrum</em>, is a long-lived species that grows slowly, matures at an advanced age, and spawns only intermittently. In the Connecticut River, there are two distinct subpopulations of shortnose sturgeon, which have been separated by the Holyoke Dam for 157 years. My research addressed the viability and persistence for these two separate populations and the effects of dispersal, variation in survival and reproduction, and catastrophes. My risk-based approach used a stage-based metapopulation model that I constructed in RAMAS<sup>®</sup> GIS incorporating the available data. Based on the existing data, this population model for the shortnose sturgeon metapopulation in the Connecticut River made several predictions. The observed stability of the two subpopulations was possible either: with reproduction in both upper and lower subpopulations and small to moderate rates of dispersal between them; or with no reproduction in the lower subpopulation, very high reproduction in the upper subpopulation and high rate of net downstream dispersal. My results provided estimates of extinction risk for the shortnose sturgeon metapopulation under various management options and highlighted three key areas for future research, demonstrating the value of a risk-based approach. This approach is particularly useful for management of long-lived aquatic species.

Accelerated Erosion and Sedimentation in Southeast Asia

2005 ◽  
Author(s):  
Avijit Gupta
Keyword(s):  
Southeast Asia ◽  
Sediment Yield ◽  
Large Scale ◽  
Drainage Basin ◽  
High Rate ◽  
Annual Rainfall ◽  
Sediment Yields ◽  
Erosion Rates ◽  
Sediment Transfer ◽  
Very High

Periodic attempts to plot global distribution of erosion and sedimentation usually attribute most of Southeast Asia with a very high sediment yield (Milliman and Meade 1983). The erosion rates and sediment yield figures are especially high for maritime Southeast Asia. Milliman and Syvitski (1992), for example, listed 3000 t km−2 yr−1 for the archipelagos and peninsulas of Southeast Asia. They provided a number of natural explanations for the high erosion rate: location near active plate margins, pyroclastic eruptions, steep slopes, and mass movements. This is also a region with considerable annual rainfall, a very substantial percentage of which tends to be concentrated in a few months and falls with high intensity. Part of Southeast Asia (the Philippines, Viet Nam, Timor) is visited by tropical cyclones with heavy, intense rainfall and possible associated wind damage to existing vegetation. The fans at the foot of slopes, the large volume of sediment stored in the channel and floodplain of the rivers, and the size of deltas all indicate a high rate of erosion and episodic sediment transfer. This episodic erosion and sediment transfer used to be controlled for most of the region by the thick cover of vegetation that once masked the slopes. When vegetation is removed soil and regolith de-structured, and natural slopes altered, the erosion rates and sediment yield reach high figures. Parts of Southeast Asia display striking anthropogenic alteration of the landscape, although the resulting accelerated erosion may be only temporary, operating on a scale of several years. Over time the affected zones shift, and slugs of sediment continue to arrive in a river but from different parts of its drainage basin. The combination of anthropogenic alteration and fragile landforms may give rise to very high local yields. Sediment yields of more than 15 000 t km−2 yr−1 have been estimated from such areas (Ruslan and Menam, cited in Lal 1987). This is undoubtedly towards the upper extreme, but current destruction of the vegetation cover due to deforestation, expansion of agriculture, mining, urbanization, and implementation of large-scale resettlement schemes has increased the sediment yield from < 102 to > 103 t km−2 yr−1.

Comorbidity of Bipolar and Substance Use Disorders

2020 ◽  
pp. 75-82
Author(s):  
Josh E. Becker ◽  
E. Sherwood Brown
Keyword(s):  
Bipolar Disorder ◽  
Substance Use ◽  
Treatment Adherence ◽  
Substance Use Disorder ◽  
Psychological Factors ◽  
High Rate ◽  
Special Treatment ◽  
Poor Treatment ◽  
Very High

Bipolar disorder and substance use disorder co-occur at very high rates. The high rate is likely due to a complex interaction of biological, social, and psychological factors, and some research suggests that use of substances may be to mitigate symptoms associated with bipolar disorder. Some studies have shown that men with bipolar disorder may be at a higher risk for a substance use disorder than women. The co-occurrence of these disorders leads to poorer treatment outcomes because of higher rates of suicidality, poor treatment adherence, lower quality of life, and more frequent relapse. This population deserves special treatment consideration.

Innovative biological treatment for sustainable development in the chemical industries

1998 ◽  
Vol 38 (4-5) ◽  
pp. 111-120 ◽  
Author(s):  
W. Wesley Eckenfelder ◽  
A. J. Englande
Keyword(s):  
Sustainable Development ◽  
Biological Treatment ◽  
Ecological Integrity ◽  
Cost Effective ◽  
Wastewater Management ◽  
Effluent Quality ◽  
Treatment Techniques ◽  
Conventional Technology ◽  
Receiving Waters ◽  
Specific Oxygen Uptake Rate

This paper presents a perspective of wastewater management in the chemical industries as related to sustainable development. The scope of wastewater management must therefore further be expanded to include the concept of ecological integrity of receiving waters. Ecological integrity of receiving waters is compromised by contaminants which are not effectively removed by Best Conventional Technology (BCT). Biological treatment typically offers the most cost-effective conversion and/or stabilization of wastewaters; however, modifications must be employed in the design and operation to provide satisfactory effluent quality. Enhanced treatment techniques for wastewaters containing high organic concentrations, VOCs, elevated TDS levels, toxics and priority pollutants are discussed. The importance of design and operational procedures including pretreatment technologies, two stage vs. single stage activated sludge, selector design and maximum specific oxygen uptake rate determinations are also presented.

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