scholarly journals Enhancing the hydrolysis of excess sludge using thermophilic Bacillus sp. Hnu under different oxygen supply conditions

2013 ◽  
Vol 78 (8) ◽  
pp. 1135-1147 ◽  
Author(s):  
Wei Zheng ◽  
Ming Li ◽  
Zheng Li ◽  
Ying Xu ◽  
Guo Ya
Keyword(s):  
Oxygen Supply ◽  
Suspended Solid ◽  
Hydrolysis Rate ◽  
Volatile Suspended Solid ◽  
Bacillus Sp ◽  
Control Test ◽  
Excess Sludge ◽  
Aerobic Conditions ◽  
Thermophilic Bacillus ◽  
Hydrolysis Of

A thermophilic Bacillus strain was isolated from excess sludge in the present study. The 16S rDNA analysis indicated that this strain was a Bacillus sp. and has not been reported previously (named Bacillus sp. Hnu). The aim of this paper was to investigate the enhanced efficiency of excess sludge hydrolysis by the addition of thermophilic Bacillus sp. Hnu under different oxygen supply conditions. The results indicated that higher temperature and more oxygen supply was advantageous to the volatile suspended solid removal ratio with the same effect to that of protease activity. The maximum volatile suspended solid removal ratio was achieved at 21.5 %, 42.5 %, and 54.4 % after 108 h digestion at pH 6.9 and 60?C and increased by 17.2 %, 38 %, and 45.4 % under anaerobic, microaerobic, and aerobic conditions compared with the control test, respectively. The hydrolysis rate constants for the anaerobic, microaerobic, and aerobic conditions were 3, 4.8, and 7 times (40?C) and 3.5, 9.8, and 11.8 times (50?C) and 2.7, 7.2, and 10.3 times (60?C). Hydrolysis performance indicated that the Bacillus sp. Hnu could accelerate the hydrolysis rate. The kinetic study showed that the hydrolysis of sludge with Bacillus sp. Hnu and the control test followed the first-order kinetics except at 60?C.

Combination of High Pressure and Thermal Hydrolysis Pretreatment Effect on Sludge

2013 ◽  
Vol 838-841 ◽  
pp. 18-22
Author(s):  
Guang Li ◽  
Xiao Xia Jiao ◽  
Jing Li ◽  
Xiang Kui Han ◽  
Lian Peng Wang
Keyword(s):  
High Pressure ◽  
Anaerobic Digestion ◽  
Organic Acids ◽  
Suspended Solid ◽  
Volatile Suspended Solid ◽  
Thermal Hydrolysis ◽  
Supernatant Fluid ◽  
Excess Sludge ◽  
Characteristics Analysis ◽  
Hydrolysis Temperature

In 110-190°C for 15-75 min of excess sludge thermal hydrolysis experiment, inspected the volatile suspended solid dissolution rate, the concentration of sludge SCOD, TCOD, components of organic acids in the supernatant fluid changes,such as sewage thermal hydrolysis characteristics, analysis the effect to improve the performance of sludge anaerobic digestion. The results show that with the increase of thermal hydrolysis temperature and time, SCOD and VFA in the sludge supernatant on rising. Under the condition of 190°C,75min, SCOD and VFA reached a maximum of 6674 mg/L,2630 mg/L; Release of sludge organic dissolved solids,COD and other major completed in the first 45 min,after 45 min changed little; Thermal hydrolysis temperature was between 90~170°C,sludge anaerobic digestion performance increases with temperature,when the temperature was higher than 170°C,sludge anaerobic digestion performance began to decline.

Hydrolysis of organic wastewater particles in laboratory scale and pilot scale biofilm reactors under anoxic and aerobic conditions

1998 ◽  
Vol 38 (8-9) ◽  
pp. 179-188 ◽  
Author(s):  
K. F. Janning ◽  
X. Le Tallec ◽  
P. Harremoës
Keyword(s):  
Organic Matter ◽  
Mass Balance ◽  
Particulate Organic Matter ◽  
Removal Rate ◽  
Pilot Scale ◽  
Laboratory Scale ◽  
Synthetic Wastewater ◽  
Aerobic Conditions ◽  
Biofilm Reactors ◽  
Hydrolysis Of

Hydrolysis and degradation of particulate organic matter has been isolated and investigated in laboratory scale and pilot scale biofilters. Wastewater was supplied to biofilm reactors in order to accumulate particulates from wastewater in the filter. When synthetic wastewater with no organic matter was supplied to the reactors, hydrolysis of the particulates was the only process occurring. Results from the laboratory scale experiments under aerobic conditions with pre-settled wastewater show that the initial removal rate is high: rV, O2 = 2.1 kg O2/(m3 d) though fast declining towards a much slower rate. A mass balance of carbon (TOC/TIC) shows that only 10% of the accumulated TOC was transformed to TIC during the 12 hour long experiment. The pilot scale hydrolysis experiment was performed in a new type of biofilm reactor - the B2A® biofilter that is characterised by a series of decreasing sized granular media (80-2.5 mm). When hydrolysis experiments were performed on the anoxic pilot biofilter with pre-screened wastewater particulates as carbon source, a rapid (rV, NO3=0.7 kg NO3-N/(m3 d)) and a slowler (rV, NO3 = 0.3 kg NO3-N/(m3 d)) removal rate were observed at an oxygen concentration of 3.5 mg O2/l. It was found that the pilot biofilter could retain significant amounts of particulate organic matter, reducing the porosity of the filter media of an average from 0.35 to 0.11. A mass balance of carbon shows that up to 40% of the total incoming TOC accumulates in the filter at high flow rates. Only up to 15% of the accumulated TOC was transformed to TIC during the 24 hour long experiment.

scholarly journals Kinetics of Enzymatic Hydrolysis of Southeast Sulawesi Sago Starch

2020 ◽  
pp. 53-61
Author(s):  
Ansharullah Ansharullah ◽  
Muhammad Natsir
Keyword(s):  
Enzymatic Hydrolysis ◽  
Maximum Velocity ◽  
Enzyme Concentration ◽  
Hydrolysis Rate ◽  
Sago Starch ◽  
Optimum Conditions ◽  
Kinetics Of ◽  
Hydrolysis Of ◽  
Substrate Concentrations ◽  
Menten Constant

The aims of this study were to characterize the kinetics of enzymatic hydrolysis of sago starch, obtained from Southeast Sulawesi Indonesia. The enzyme used for hydrolysis was bacterial ∝-amylase (Termamyl 120L from Bacillus licheniformis, E. C. 3.2.1.1).  The method to determine the initial velocity (Vo) of the hydrolysis was developed by differentiation a nonlinear equation (NLE).  The Vo of the hydrolysis was measured at various pH (6.0, 6.5,and 7.0), temperatures (40, 60, 75 and 95oC), enzyme concentrations (0.5, 1.0, 1.5 and 2.0 µg per mL) and in the presence of 70 ppm Ca++. The optimum conditions of this experiment were found to be at pH 6.5 – 7.0 and 75oC, and the Vo increased with increasing enzyme concentration. The Vo values at various substrate concentrations were also determined, which were then used to calculate the enzymes kinetics constant of the hydrolysis, including Michaelis-Menten constant (Km) and maximum velocity (Vmax) using a Hanes plot.  Km and Vmax values were found to be higher in the measurement at pH 7.0 and 75oC. The Km values  at four  different combinations of pH and temperatures (pH 6.5, 40oC; pH 6.5, 75oC; pH 7.0, 40oC; pH 7.0, 75oC) were found to be 0.86, 3.23, 0.77 and 3.83 mg/mL, respectively; and Vmax values were 17.5, 54.3, 20.3 and 57.1 µg/mL/min, respectively. The results obtained showed that hydrolysis rate of this starch was somewhat low.

Hydrolysis of MgH2 in MgCl2 solutions as an effective way for hydrogen generation

2021 ◽  
pp. 38-52
Author(s):  
V. Berezovets ◽  
◽  
A. Kytsya ◽  
Yu. Verbovytskyy ◽  
I. Zavaliy ◽  
...  
Keyword(s):  
Hydrogen Generation ◽  
Strong Acid ◽  
Magnesium Hydride ◽  
Hydrolysis Reaction ◽  
Hydrolysis Rate ◽  
Reaction Yield ◽  
Buffer Solution ◽  
Passivation Film ◽  
Products Of Reaction ◽  
Hydrolysis Of

Magnesium hydride (MgH2) has a high hydrogen storage capacity (7.6 wt%) and the Mg element is abundant on the earth. Due to its strong reduction ability, even at room temperature it can provide the hydrogen yield reaching 15.2 wt% H (1703 mL/g) when interacting with water, which makes it very attractive for the application in supplying hydrogen for autonomous H energy systems. However, the hydrolysis reaction is rapidly inhibited by the Mg(OH)2 passivation layer formed on the surface of MgH2. In order to remove the passivation film and improve the efficiency of the MgH2 hydrolysis process, several methods including alloying, ball milling, changing the aqueous solution, have been successfully utilized. In this paper the process of hydrolysis of magnesium hydride in aqueous solutions of MgCl2 used as a promotor of the interaction has been studied in detail. It was found that the initial hydrolysis rate, pH of the reaction mixture, and overall reaction yield are all linearly dependent of the logarithm of MgCl2 concentration. It has been shown that pH of the reaction mixture in the presence of MgCl2 is well described by considering a system “weak base and its salt with strong acid” type buffer solution. Reference data for this hydrolysis reaction were also carefully analyzed. The mechanism and the kinetic model of the process of MgH2 hydrolysis in water solutions involved passivation of the MgH2 surface by the formed Mg(OH)2 precipitate followed by its repassivation have been proposed. The obtained after the hydrolysis reactions precipitates were studied using XRD and EDS. It was found also that the final products of reaction consist of Mg(OH)2 (brucsite type) and remaining MgH2. This fact shows that the formation of solid species such as MgCl2 xMgO yH2O at the studied conditions is unlikely and decreasing of pH the reaction mixture has a different nature.

scholarly journals BIODEGRADASI REMAZOL BRILIANT BLUE DALAM SISTEM BIOFILTRASI VERTIKAL DENGAN INOKULUM BAKTERI DARI SEDIMEN SUNGAI MATI IMAM BONJOL DENPASAR

2017 ◽  
Vol 11 (1) ◽  
pp. 8 ◽  
Author(s):  
Luh Putri Kriswidatari ◽  
I W Budiarsa Suyasa ◽  
I Made Siaka
Keyword(s):  
Active Suspension ◽  
Suspended Solid ◽  
Brilliant Blue ◽  
Second Phase ◽  
Pseudomonas Sp ◽  
Volatile Suspended Solid ◽  
A Value ◽  
Filtration System ◽  
Attached Bacteria ◽  
Bacterial Inoculum

BIODEGRADATION REMAZOL BRILLIANT BLUE IN VERTICAL FILTRATION SYSTEM WITH INOKULUM BACTERIA FROM DIED SEDIMEN RIVER IMAM BONJOL DENPASARThe biodegradation research of Remazol Brilliant Blue (RBB) has been done in vertical biofiltration systems with bacterial inoculum that had seed from soil Mati River Imam Bonjol Denpasar. This aims of research are to obtain the best active suspension grown from soil samples of Mati river sediment and to determine the magnitude of the effectiveness and capacity of biosystem . The artificial waste water of RBB has made with a concentration of 200 mg/L. In the first phase, the best active suspension is obtained by determining the value of VSS ( Volatile Suspended Solid ) is the highest as a source of inoculum of bacteria capable of degrading RBB. While the second phase, the effectiveness and capacity of biosystem is obtained by determining the levels of waste of artificial RBB vertical biofiltration system (biosystem). Biofilm has made with attached bacteria consortium in volcanic rock for 7 days. RBB subsequently incoporated into it to determine the concentration of it and to determine the effectiveness and capacity and identified the bacteria contained in biosystem. The results showed the best sludge active from soil sediments of the Mati River Imam Bonjol Gang Keladian with a value of Volatile Suspended Solid (VSS) highest of 17200 mg/L when the sreeding time of 48 hours. The results of processing using biosystem known to decreased when the processing time from 6 hours up to 114 hours, from concentration of 200 mg/L to 19.6211 mg/L. Then the prosses has increased again into 19.8209 mg/L at the time to 120 hours. The highest effectivity of biosystem to degrading remazol brilliant blue of  90.19 % for 114 hours , while the highest capacity is obtained from the biosystem is 1.6525 x mg /g for 114 hours. The bacteria that act to decreased identified as Pseudomonas sp., Aeromonas sp . and Plesiomonas sp, with Pseudomonas sp more dominant in the  degrading of dye RBB. The value of the colonists before degradation of 7.2 x CFU/gr and the value after the degradation of 2.6 x CFU/gr.

Functional role of ecto-ATPase activity in goldfish hepatocytes

1998 ◽  
Vol 274 (4) ◽  
pp. R1031-R1038 ◽  
Author(s):  
Pablo J. Schwarzbaum ◽  
Michael E. Frischmann ◽  
Gerhard Krumschnabel ◽  
Rolando C. Rossi ◽  
Wolfgang Wieser
Keyword(s):  
Atpase Activity ◽  
Functional Role ◽  
Maximal Activity ◽  
Hydrolysis Rate ◽  
Hyperbolic Function ◽  
Extracellular Release ◽  
Transport Atpases ◽  
Hydrolysis Of ◽  
Hepatocyte Suspension

Extracellular [γ-32P]ATP added to a suspension of goldfish hepatocytes can be hydrolyzed to ADP plus γ-32Pidue to the presence of an ecto-ATPase located in the plasma membrane. Ecto-ATPase activity was a hyperbolic function of ATP concentration ([ATP]), with apparent maximal activity of 8.3 ± 0.4 nmol Pi ⋅ (106cells)−1 ⋅ min−1and substrate concentration at which a half-maximal hydrolysis rate is obtained of 667 ± 123 μM. Ecto-ATPase activity was inhibited 70% by suramin but was insensitive to inhibitors of transport ATPases. Addition of 5 μM [α-32P]ATP to the hepatocyte suspension induced the extracellular release of α-32Pi[8.2 pmol ⋅ (106cells)−1 ⋅ min−1] and adenosine, suggesting the presence of other ectonucleotidase(s). Exposure of cell suspensions to 5 μM [2,8-3H]ATP resulted in uptake of [2,8-3H]adenosine at 7.9 pmol ⋅ (106cells)−1 ⋅ min−1. Addition of low micromolar [ATP] strongly increased cytosolic free Ca2+([Formula: see text]). This effect could be partially mimicked by adenosine 5′- O-(3-thiotriphosphate), a nonhydrolyzable analog of ATP. The blockage of both glycolysis and oxidative phosphorylation led to a sixfold increase of[Formula: see text] and an 80% decrease of intracellular ATP, but ecto-ATPase activity was insensitive to these metabolic changes. Ecto-ATPase activity represents the first step leading to the complete hydrolysis of extracellular ATP, which allows 1) termination of the action of ATP on specific purinoceptors and 2) the resulting adenosine to be taken up by the cells.

scholarly journals Kinetics of alkoxysilanes hydrolysis: An empirical approach

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ahmed A. Issa ◽  
Marwa El-Azazy ◽  
Adriaan S. Luyt
Keyword(s):  
Reaction Mechanisms ◽  
Hydrolysis Reaction ◽  
Hydrolysis Rate ◽  
Coupling Agents ◽  
Linear Free Energy Relationship ◽  
Acidic Media ◽  
Linear Free Energy ◽  
Primary Materials ◽  
Kinetics Of ◽  
Hydrolysis Of

AbstractAlkoxysilanes and organoalkoxysilanes are primary materials in several industries, e.g. coating, anti-corrosion treatment, fabrication of stationary phase for chromatography, and coupling agents. The hydrolytic polycondensation reactions and final product can be controlled by adjusting the hydrolysis reaction, which was investigated under a variety of conditions, such as different alkoxysilanes, solvents, and catalysts by using gas chromatography. The hydrolysis rate of alkoxysilanes shows a dependence on the alkoxysilane structure (especially the organic attachments), solvent properties, and the catalyst dissociation constant and solubility. Some of the alkoxysilanes exhibit intramolecular catalysis. Hydrogen bonding plays an important role in the enhancement of the hydrolysis reaction, as well as the dipole moment of the alkoxysilanes, especially in acetonitrile. There is a relationship between the experimentally calculated polarity by the Taft equation and the reactivity, but it shows different responses depending on the solvent. It was found that negative and positive charges are respectively accumulated in the transition state in alkaline and acidic media. The reaction mechanisms are somewhat different from those previously suggested. Finally, it was found that enthalpy–entropy compensation (EEC) effect and isokinetic relationships (IKR) are exhibited during the hydrolysis of CTES in different solvents and catalysts; therefore, the reaction has a linear free energy relationship (LFER).

Sign in / Sign up

Export Citation Format

Share Document