Aerobic sludge digestion—a suggested design procedure

1981 ◽  
Vol 8 (1) ◽  
pp. 9-15
Author(s):  
D. S. Mavinic ◽  
D. A. Koers
Keyword(s):  
Design Procedure ◽  
Design Guidelines ◽  
Full Scale ◽  
Cold Climate ◽  
High Rate ◽  
Published Data ◽  
Plant Design ◽  
Sludge Digestion ◽  
Kinetic Coefficients ◽  
Aerobic Sludge

With high-rate activated sludge as feed, various modes of digestion were studied on a laboratory scale at 20, 10, and 5 °C. This study was performed to develop design guidelines, operating criteria, and kinetic coefficients for low-temperature aerobic sludge digestion. To develop a possible scale factor for extrapolation of laboratory results to full-scale conditions, a field evaluation program was conducted to collect and analyze full-scale data from three independent sources.In this manuscript a summary of previously published data, as well as some of the latest research findings, have been presented. In addition, this paper outlines a new design procedure for use in "sizing" a typical aerobic digester; as well, a method for determination of oxygen requirements in the digester tanks is described.This design procedure is based primarily on a graphical solution involving several variables, whereby the percentage reduction of volatile suspended solids is plotted against the product of temperature and sludge age. Included in this presentation is a comparison between the use (and misuse) of kinetic data in traditional design procedures. The design methodology presented has already proven to be a valuable and cost-effective tool, especially for cold-climate package plant design.

Upgrading Wastewater Treatment Plants with Anaerobic Selectors

1990 ◽  
Vol 22 (7-8) ◽  
pp. 35-43
Author(s):  
K. D. Tracy ◽  
S. N. Hong
Keyword(s):  
Phosphorus Removal ◽  
Wastewater Treatment Plants ◽  
Full Scale ◽  
High Rate ◽  
Nitrogen Control ◽  
Biological Phosphorus Removal ◽  
Conventional Activated Sludge ◽  
And Performance ◽  
Activated Sludge Processes ◽  
Biological Phosphorus

The anaerobic selector of the A/0™ process offers many advantages over conventional activated sludge processes with respect to process performance and operational stability. This high-rate, single-sludge process has been successfully demonstrated in full-scale operations for biological phosphorus removal and total nitrogen control in addition to BOD and TSS removal. This process can be easily utilized in upgrading existing treatment plants to meet stringent discharge limitations and to provide capacity expansion. Upgrades of two full-scale installations are described and performance data from the two facilities are presented.

Wastewater Lagoons in a Cold Climate

1987 ◽  
Vol 19 (12) ◽  
pp. 47-53 ◽  
Author(s):  
J. A. Oleszkiewicz ◽  
A. B. Sparling
Keyword(s):  
Control Mechanism ◽  
Maximum Load ◽  
Domestic Sewage ◽  
Full Scale ◽  
Cold Climate ◽  
Odor Control ◽  
Intermittent Rivers ◽  
In Series ◽  
Break Up ◽  
Lagoon Systems

Severe climate, intermittent rivers and availability of land make facultative lagoon systems the method of choice in treating primarily domestic sewage from smaller municipalities. The lagoons are designed on a recommended maximum load of 55 kgBOD5/ha d to first cell, while the second cell provides storage. The discharge is twice annually and the occurrence of the spring ice break-up odor period is one of the primary criteria limiting this load. Based on full scale performance data, it is demonstrated that, from the standpoint of odor nuisance, the load to the first cell should be kept equal to or less than 35 kg/ha d. Full scale studies of an overloaded lagoon system show the futility of under-ice aeration for odor control. Mechanism of natural odor control during ice break up is elucidated. Upgrading of the overloaded systems or lagoons receiving significant industrial contribution is best achieved by construction of a 3–5 m deep aerated lagoon preceding the two or more facultative cells in series.

scholarly journals Microbiome of Seven Full-Scale Anaerobic Digestion Plants in South Korea: Effect of Feedstock and Operational Parameters

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 665
Author(s):  
Michal Sposob ◽  
Hee-Sung Moon ◽  
Dongjin Lee ◽  
Yeo-Myeong Yun
Keyword(s):  
Microbial Population ◽  
Ammonium Nitrogen ◽  
H2 Production ◽  
Full Scale ◽  
Organic Loading Rate ◽  
Operational Parameters ◽  
Sludge Digestion ◽  
Secondary Sludge ◽  
Potential Activity ◽  
Total Ammonium

In this study, the microbiomes linked with the operational parameters in seven mesophilic full-scale AD plants mainly treating food waste (four plants) and sewage sludge (three plants) were analyzed. The results obtained indicated lower diversity and evenness of the microbial population in sludge digestion (SD) plants compared to food digestion (FD) plants. Candidatus Accumulibacter dominated (up to 42.1%) in SD plants due to microbial immigration from fed secondary sludge (up to 89%). Its potential activity in SD plants was correlated to H2 production, which was related to the dominance of hydrogenotrophic methanogens (Methanococcus). In FD plants, a balance between the hydrogenotrophic and methylotrophic pathways was found, while Flavobacterium and Levilinea played an important role during acidogenesis. Levilinea also expressed sensitivity to ammonia in FD plants. The substantial differences in hydraulic retention time (HRT), organic loading rate (OLR), and total ammonium nitrogen (TAN) among the studied FD plants did not influence the archaeal methane production pathway. In addition, the bacterial genera responsible for acetate production through syntrophy and homoacetogenesis (Smithella, Treponema) were present in all the plants studied.

Autoheated thermophilic aerobic sludge digestion and metal bioleaching in a two-stage reactor system

2010 ◽  
Vol 22 (2) ◽  
pp. 230-236 ◽  
Author(s):  
Rohan Jain ◽  
Ashish Pathak ◽  
T.R. Sreekrishnan ◽  
M.G. Dastidar
Keyword(s):  
Reactor System ◽  
Two Stage ◽  
Sludge Digestion ◽  
Aerobic Sludge

Upgrading of a small wastewater treatment plant in a cold climate region using a moving bed biofilm reactor (MBBR) system

2000 ◽  
Vol 41 (1) ◽  
pp. 177-185 ◽  
Author(s):  
G. Andreottola ◽  
P. Foladori ◽  
M. Ragazzi
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Internal Surface ◽  
Full Scale ◽  
Biofilm Reactor ◽  
Cold Climate ◽  
Moving Bed Biofilm Reactor ◽  
Moving Bed ◽  
North East

The aim of this study was to evaluate the performance of a full-scale upgrading of an existing RBC wastewater treatment plant with a MBBR (Moving Bed Biofilm Reactor) system, installed in a tank previously used for sludge aerobic digestion. The full-scale plant is located in a mountain resort in the North-East of Italy. Due to the fact that the people varied during the year's seasons (2000 resident people and 2000 tourists) the RBC system was insufficient to meet the effluent standards. The MBBR applied system consists of the FLOCOR-RMP®plastic media with a specific surface area of about 160 m2/m3 (internal surface only). Nitrogen and carbon removal from wastewater was investigated over a 1-year period, with two different plant lay-outs: one-stage (only MBBR) and two stage system (MBBR and rotating biological contactors in series). The systems have been operated at low temperature (5–15°C). 50% of the MBBR volume (V=79 m3) was filled. The organic and ammonium loads were in the average 7.9 gCOD m−2 d−1 and 0.9 g NH4−N m−2 d−1. Typical carbon and nitrogen removals in MBBR at temperature lower than 8°C were respectively 73% and 72%.

scholarly journals Nature, Position, and Frequency of Mutations Made in a Single Cycle of HIV-1 Replication

2010 ◽  
Vol 84 (19) ◽  
pp. 9864-9878 ◽  
Author(s):  
Michael E. Abram ◽  
Andrea L. Ferris ◽  
Wei Shao ◽  
W. Gregory Alvord ◽  
Stephen H. Hughes
Keyword(s):  
Viral Replication ◽  
Mutation Rate ◽  
Hot Spots ◽  
High Rate ◽  
Published Data ◽  
Single Cycle ◽  
Efficient System ◽  
Hiv 1

ABSTRACT There is considerable HIV-1 variation in patients. The extent of the variation is due to the high rate of viral replication, the high viral load, and the errors made during viral replication. Mutations can arise from errors made either by host DNA-dependent RNA polymerase II or by HIV-1 reverse transcriptase (RT), but the relative contributions of these two enzymes to the mutation rate are unknown. In addition, mutations in RT can affect its fidelity, but the effect of mutations in RT on the nature of the mutations that arise in vivo is poorly understood. We have developed an efficient system, based on existing technology, to analyze the mutations that arise in an HIV-1 vector in a single cycle of replication. A lacZα reporter gene is used to identify viral DNAs that contain mutations which are analyzed by DNA sequencing. The forward mutation rate in this system is 1.4 × 10−5 mutations/bp/cycle, equivalent to the retroviral average. This rate is about 3-fold lower than previously reported for HIV-1 in vivo and is much lower than what has been reported for purified HIV-1 RT in vitro. Although the mutation rate was not affected by the orientation of lacZα, the sites favored for mutations (hot spots) in lacZα depended on which strand of lacZα was present in the viral RNA. The pattern of hot spots seen in lacZα in vivo did not match any of the published data obtained when purified RT was used to copy lacZα in vitro.

Fate of pathogens in thermophilic aerobic sludge digestion

1982 ◽  
Vol 16 (6) ◽  
pp. 1051-1060 ◽  
Author(s):  
Randolph M. Kabrick ◽  
William J. Jewell
Keyword(s):  
Sludge Digestion ◽  
Aerobic Sludge
Sign in / Sign up

Export Citation Format

Share Document