Start-up performance of Anammox process in a fixed bed reactor (FBR) filled with honeycomb-like polypropylene carriers

2016 ◽  
Vol 73 (8) ◽  
pp. 1848-1854 ◽  
Author(s):  
Tao Wang ◽  
Boxiong Shen ◽  
Sha Zhang ◽  
Zhiqiang Wang ◽  
Li Tian
Keyword(s):  
Shock Loading ◽  
Nitrogen Concentration ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Nitrite Accumulation ◽  
Reactor Performance ◽  
Retention Capacity ◽  
Positive Role ◽  
Start Up ◽  
Anammox Activity

Novel honeycomb-like carriers, made of polypropylene, were applied to enhance biomass retention capacity so as to improve Anammox start-up performance in a fixed bed reactor (FBR). The reactor was operated for 3 months. On day 45, Anammox activity appeared. After 61 days' operation, the removal efficiencies of ammonium and nitrite were both over 91% based on 70 mg N L−1 of the influent ammonium and influent nitrite, indicating that a remarkable Anammox activity was attained. A final specific Anammox activity of 0.12 g NH4+-N gVSS−1 d−1 was reached (VSS: volatile suspended solids). The FBR showed a good capacity for resisting shock loading and was more able to resist shock loading of nitrogen concentration than resist hydraulic shock loading. Phylogenetic analysis showed that Candidatus Brocadia anammoxidans' and Candidatus Kuenenia stuttgartiensis' were detected in the mature biofilm, and Candidatus Brocadia anammoxidans' was the dominant Anammox strain. Candidatus Kuenenia stuttgartiensis' played a positive role in the reactor performance, as it could consumed nitrite quickly and efficiently so as to avoid an adverse effect of temporary nitrite accumulation. The results showed that the honeycomb-like carriers were suitable for start-up of Anammox.

scholarly journals Start-up of anaerobic reactors for slaughterhouse wastewater treatment

2015 ◽  
Vol 35 (2) ◽  
pp. 331-339 ◽  
Author(s):  
RONALDO FIA ◽  
ERLON L. PEREIRA ◽  
FÁTIMA R. L. FIA ◽  
DÉBORA G. EMBOABA ◽  
EMANUEL M. GOMES
Keyword(s):  
Wastewater Treatment ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Upflow Anaerobic Sludge Blanket ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
Stable Operation ◽  
Slaughterhouse Wastewater ◽  
Start Up ◽  
Bicarbonate Alkalinity

This study aimed to evaluate the start-up of a horizontal anaerobic fixed bed reactor (HAFBR) followed by an upflow anaerobic sludge blanket (UASB) for the slaughterhouse wastewater treatment. HAFBR was filled with bamboo rings and had 1.2 m in length, 0.10 m in diameter and volume of 7.5 L. The UASB had the volume of 15 L. The HAFBR and UASB operated at organic loading rate and hydraulic retention time average of 8.46 and 3.77 kg m-3 d-1 of COD and 0.53 and 0.98 days, respectively. During 150 days of monitoring system it was found pH 6.8, relatively high values of bicarbonate alkalinity (> 1000 mg L-1) and reduced values of volatile acids (70 to 150 mg L-1), which afforded average removal efficiencies of COD total and total suspended solids of the order of 31 and 23% in HAFBR and 79% and 63% in UASB. It can be concluded that the generation and consumption of bicarbonate alkalinity and total volatile acids, thereby maintaining the pH during the study indicated stable operation of the reactors. The COD removal in the reactors was satisfactory especially when it considers that the assessment was conducted in a period of adaptation of organisms to the effluent and also the high organic load applied during this period.

Activity and selectivity of non-uniform bifunctional catalysts. Analysis of the fixed-bed reactor performance

1986 ◽  
Vol 51 (11) ◽  
pp. 2509-2520 ◽  
Author(s):  
Darío R. Ardiles
Keyword(s):  
Fixed Bed ◽  
Product Distribution ◽  
Bifunctional Catalyst ◽  
Fixed Bed Reactor ◽  
Bifunctional Catalysts ◽  
Reactor Performance ◽  
Catalytic Functions ◽  
Reaction Schemes

This paper reports a study about the effect of activity distributions of a bifunctional catalyst on the conversion and product distribution in a fixed-bed reactor. Uniform as well as increasing and decreasing activity profiles of both catalytic functions are considered. The analysis is performed assuming three different reaction schemes. Results show that reactor performance is greatly affected by the use of catalysts with non-uniform activity distributions.

Optimal catalyst activity distribution in fixed-bed reactor with catalyst deactivation

1989 ◽  
Vol 54 (2) ◽  
pp. 375-387 ◽  
Author(s):  
Jozef Markoš ◽  
Alena Brunovská
Keyword(s):  
Catalyst Deactivation ◽  
Active Catalyst ◽  
Catalyst Activity ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Catalytic Reactor ◽  
Reactor Performance ◽  
Thiele Modulus ◽  
Activity Distribution ◽  
Parameter Ratio

In this paper the influence of the active catalyst location in a pellet on fixed-bed catalytic reactor performance is described. The optimal activity distribution as a function of an economic parameter (ratio of product and catalyst costs), Thiele modulus and Damkohler number is estimated.

Characterization of Novel Sorbents for Mercury Removal at Elevated Temperature

2015 ◽  
Vol 656-657 ◽  
pp. 23-27
Author(s):  
Han Wen Cheng ◽  
Ching Tsung Yu
Keyword(s):  
Elevated Temperature ◽  
Transition Metals ◽  
Surface Area ◽  
Fixed Bed ◽  
Elemental Mercury ◽  
Fixed Bed Reactor ◽  
Mercury Removal ◽  
Bet Surface Area ◽  
Precipitation Method ◽  
Retention Capacity

The novel carbonate sorbents of Mg–Al–CO3 and (Mg3−x, Cux)–Al–CO3, were synthesized by co-precipitation method with individual nitrate salt of metal ions under alkaline conditions. The synthetic sorbent was characterized by analysis techniques such as BET surface area analysis, X-ray diffraction (XRD), and scanning electron microscopy (SEM). Elemental mercury capture experiments were carried out in a fixed-bed reactor including Hg permeation source, furnace, and Hg analyzer, which was conducted at temperature ranging from 30 to 300 o C. The major results showed that the surface area of material was significantly increased via incorporating Cu2+ into Mg–Al–CO3, accordingly enhancing Hg retention capacity of sorbents. SEM imagines displayed the layer appearance of Mg/Al and Mg/Cu/Al sorbents. Crystalline analysis indicated lamella structure accompanied with metal oxides within materials. Mercury removal tests demonstrated that the breakthrough time increased with temperature by adding transition metals to Mg–Al–CO3 as (Mg3−x, Cux)–Al–CO3. Hg uptake by the (Mg3−x, Cux)–Al–CO3 sorbent rapidly increased with elevated temperature up to 200 o C and reached the maximum capacity of 12.93 μg/g, and then gradually decreased after 300 o C. Surface area and unique properties of transition metals are the reason toward improving Hg capture sorbent. These results represent the feasibility of using such Hg sorbents for elemental mercury removal under elevated temperature conditions, and the detail mechanism is needed to be further studied.

The Optimization of an Ammonia Synthesis Reactor Using Genetic Algorithm

2009 ◽  
Vol 6 (1) ◽  
Author(s):  
Mohammad Taghi Sadeghi ◽  
Azam Kavianiboroujeni
Keyword(s):  
Genetic Algorithm ◽  
Ammonia Synthesis ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Ammonia Production ◽  
Dimensional Model ◽  
Reactor Performance ◽  
One Dimensional ◽  
Operational Conditions ◽  
Quench Temperature

An industrial ammonia synthesis reactor was studied in order to optimize its operational conditions by means of increasing overall ammonia production. A heterogeneous, one-dimensional model and a two-dimensional rigorous model were utilized to evaluate the process behavior. The simulation results of the two models were compared with data from an industrial ammonia plant. The one-dimensional model was found to be adequate for optimization purposes. Applying the Genetic Algorithm (GA) as a powerful method for complex problems, the model was employed to optimize the reactor performance in varying its quench flows. The optimal temperature profile along the fixed bed reactor was studied by changing independent variables including the quench temperature and the quench flow rates. Optimization results show that the optimum quench temperature is about 615°K and that the optimum quench flows can enhance ammonia production rate by 3.3%.

scholarly journals Encapsulated catalase from Serratia genus for H2O2 decomposition in food applications

2018 ◽  
Vol 20 (4) ◽  
pp. 39-43 ◽  
Author(s):  
Katarzyna Czyzewska ◽  
Anna Trusek
Keyword(s):  
High Activity ◽  
Fixed Bed ◽  
Industrial Applications ◽  
Fixed Bed Reactor ◽  
Reactor Performance ◽  
Operational Conditions ◽  
H2o2 Decomposition ◽  
Wide Range ◽  
Immobilized Catalase ◽  
Food Applications

Abstract The recombinant catalase isolated from a psychrotolerant microorganism belonging to Serratia genus exhibits a high activity in a wide range of pH. Due to a great catalytic potential in operational conditions, it can be used in various industrial applications whereby it acts as a hydrogen peroxide scavenger. To reduce the cost of biocatalyst the enzyme encapsulation into a hydrogel structure was proposed. The obtained results showed a high activity of encapsulated catalase in acidic conditions (pH in range 4.4 - 6.6) and at low temperatures (6-15°C). Moreover, immobilized catalase exhibited a high stability in natural media, especially in milk. Its activity during peroxide decomposition in milk, the possibility of re-using, as well as the fixed bed reactor performance confirmed wide application possibilities. High values of enzyme and substrate concentrations led to the beads burst due to rapid oxygen diffusion from the capsules, thus they are limited.

Electrical conductivity as a state indicator for the start-up period of anaerobic fixed-bed reactors

2016 ◽  
Vol 73 (9) ◽  
pp. 2294-2300 ◽  
Author(s):  
A. Robles ◽  
E. Latrille ◽  
J. Ribes ◽  
N. Bernet ◽  
J. P. Steyer
Keyword(s):  
Electrical Conductivity ◽  
Production Rate ◽  
Methane Production ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Bicarbonate Concentration ◽  
Fixed Bed Reactors ◽  
Start Up ◽  
On Line ◽  
Methane Production Rate

The aim of this work was to analyse the applicability of electrical conductivity sensors for on-line monitoring the start-up period of an anaerobic fixed-bed reactor. The evolution of bicarbonate concentration and methane production rate was analysed. Strong linear relationships between electrical conductivity and both bicarbonate concentration and methane production rate were observed. On-line estimations of the studied parameters were carried out in a new start-up period by applying simple linear regression models, which resulted in a good concordance between both observed and predicted values. Electrical conductivity sensors were therefore identified as an interesting method for monitoring the start-up period of anaerobic fixed-bed reactors due to its reliability, robustness, easy operation, low cost, and minimum maintenance compared with the currently used sensors.

Kinetics of H2S Sorption on Manganese Oxide and Mn-Fe-Cu Mixed Oxide Prepared by the Complexation Technique

2006 ◽  
Vol 4 (1) ◽  
Author(s):  
Pinar Caglayan ◽  
Sena Yasyerli ◽  
Irfan Ar ◽  
Gulsen Dogu ◽  
Timur Dogu
Keyword(s):  
Manganese Oxide ◽  
Mixed Oxide ◽  
High Surface ◽  
High Surface Area ◽  
Fixed Bed ◽  
Breakthrough Curves ◽  
Hydrogen Gas ◽  
Fixed Bed Reactor ◽  
High Porosity ◽  
Retention Capacity

Hydrogen sulfide sorption activities of manganese oxide and Mn-Fe-Cu mixed oxide sorbents were examined in a fixed bed reactor. Sulfur retention capacity of Mn-O sorbent was found to be quite high at 600 °C both in the absence and presence of hydrogen gas (0.17 and 0.14 g S/g sorbent, respectively). This sorbent has a high porosity and a relatively high surface area. Best regeneration temperature of this sorbent was found as 700 °C, with a gas stream containing 6% oxygen in nitrogen. Mn-Fe-Cu mixed oxide sorbent had a lower sulfur retention capacity (0.07 g S/g sorbent). However, both of these sorbents gave quite high initial sorption rate constants, resulting very sharp breakthrough curves. Deactivation model was shown to give good agreement with the experimental H2S breakthrough curves.

scholarly journals Morphological study of biomass during the start-up period of a fixed-bed anaerobic reactor treating domestic sewage

2005 ◽  
Vol 48 (5) ◽  
pp. 841-849 ◽  
Author(s):  
Cláudio Antonio Andrade Lima ◽  
Rogers Ribeiro ◽  
Eugenio Foresti ◽  
Marcelo Zaiat
Keyword(s):  
Polyurethane Foam ◽  
Morphological Study ◽  
Extracellular Polymeric Substances ◽  
Fixed Bed ◽  
Morphological Characteristics ◽  
Morphological Diversity ◽  
Domestic Sewage ◽  
Fixed Bed Reactor ◽  
Start Up ◽  
Colonization Process

This work focused on a morphological study of the microorganisms attached to polyurethane foam matrices in a horizontal-flow anaerobic immobilized biomass (HAIB) reactor treating domestic sewage. The experiments consisted of monitoring the biomass colonization process of foam matrices in terms of the amount of retained biomass and the morphological characteristics of the cells attached to the support during the start-up period. Non-fluorescent rods and cocci were found to predominate in the process of attachment to the polyurethane foam surface. From the 10th week of operation onwards, an increase was observed in the morphological diversity, mainly due to rods, cocci, and Methanosaeta-like archaeal cells. Hydrodynamic problems, such as bed clogging and channeling occurred in the fixed-bed reactor, mainly due to the production of extracellular polymeric substances and their accumulation in the interstices of the bed causing a gradual deterioration of its performance, which eventually led to the system's collapse. These results demonstrated the importance and usefulness of monitoring the dynamics of the formation of biofilm during the start-up period of HAIB reactors, since it allowed the identification of operational problems.

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