Control of refractory pollutants as useful resources by hydrothermal reaction coupled with biological treatment methods

2006 ◽  
Vol 1 (3) ◽  
Author(s):  
K. Kim ◽  
M. Fujita ◽  
H. Daimon ◽  
K. Fujie
Keyword(s):  
Biological Treatment ◽  
Hydrothermal Reaction ◽  
Carbon Sources ◽  
Poly Vinyl Alcohol ◽  
Excess Sludge ◽  
Hydrothermal Conditions ◽  
Structural Conversion ◽  
Treatment Methods ◽  
Chloroacetic Acids ◽  
The Moment

Relationship between structural conversion of refractory pollutants and their biodegradability improvement was clarified under various hydrothermal conditions to know the usability of treated refractory pollutants in biological treatment methods. Hydrothermal reaction was also verified by using real wastewater. High-molecular-weight structured poly vinyl alcohol and hydrocarbon structured chloroacetic acids were partially fractured by hydrolysis and dehydration at the beginning of hydrothermal reaction. Then partially fractured refractory pollutants were rapidly converted to easily degradable substances by thermal decomposition depending on hydrothermal conditions. This significant change occurred within 3 min from the moment reaching the desired conditions at 350 and 400oC. These results were very similar to the results of soybean milk, except dyeing wastewater involving aromatic compounds. Excess sludge treated by hydrothermal reaction was also converted to easily degradable substrate as carbon sources in a bioreactor. Hydrothermal reaction should be adjusted to increase the amount of biodegradable products in reactants, without much reduction of total organic carbon. The content change of refractory pollutants and excess sludge by hydrothermal reaction was the most important factor on the viewpoint of treated reactant reuse, for the following biological treatment methods.

Application of hydrothermal reaction for excess sludge reuse as carbon sources in biological phosphorus removal

2005 ◽  
Vol 52 (10-11) ◽  
pp. 533-541 ◽  
Author(s):  
K. Kim ◽  
M. Fujita ◽  
H. Daimon ◽  
K. Fujie
Keyword(s):  
Reaction Temperature ◽  
Phosphorus Removal ◽  
Biological Treatment ◽  
Treatment Process ◽  
Hydrothermal Reaction ◽  
Carbon Sources ◽  
Biological Phosphorus Removal ◽  
Excess Sludge ◽  
Biological Phosphorus ◽  
Biological Treatment Process

An application of hydrothermal reaction was investigated to reuse excess sludge as carbon sources for enhancement of biological phosphorus removal. Under the tested conditions, solubilization of treated excess sludge did not present much variation, sustaining around 65%, except the results obtained at 400°C. Biodegradability of excess sludge was improved through its content change by the reaction, without much reduction of carbon contents even in 7min. From the results of respirometric test, readily biodegradable substrate was found at 300°C. Then its portion of reaction products increased with increasing reaction temperature. In the readily biodegradable substrate, acetic and propionic acid, which are useful carbon sources for phosphorus accumulating microorganism under anaerobic condition, increased with increasing reaction temperature. Hydrothermal reaction might be accepted as suitable pretreatment method to treat excess sludge prior to biological treatment process. This technology also secures excess sludge reuse, enhancing biological phosphorus removal and improvement of biological treatment process.

Innovative Biological Treatment Methods for Degenerative Disc Disease

2022 ◽  
Vol 157 ◽  
pp. 282-299
Author(s):  
Sertac Kirnaz ◽  
Sunidhi Singh ◽  
Charisse Capadona ◽  
Marianne Lintz ◽  
Jacob L. Goldberg ◽  
...  
Keyword(s):  
Degenerative Disc Disease ◽  
Biological Treatment ◽  
Disc Disease ◽  
Treatment Methods ◽  
Degenerative Disc

Low Temperature Hydrothermal Synthesis of Nanophase BaTiO3 and BaFe12O19 Powders

1996 ◽  
Vol 457 ◽  
Author(s):  
Fatih Dogan ◽  
Shawn O'rourke ◽  
Mao-Xu Qian ◽  
Mehmet Sarikaya
Keyword(s):  
Particle Size ◽  
Hydrothermal Reaction ◽  
Average Particle Size ◽  
Reaction Times ◽  
Nanocrystalline Powders ◽  
Molar Ratio ◽  
Average Particle ◽  
Hydrothermal Conditions ◽  
Processing Variables ◽  
Xrd And Tem

ABSTRACTNanocrystalline powders with an average particle size of 50 nm has been synthesized in two materials systems under hydrothermal conditions below 100°C. Processing variables, such as temperature, concentration and molar ratio of reactants and reaction time were optimized to obtain particles of reduced size and stoichiometric compositions. Hydrothermal reaction takes place between Ba(OH)2 solution and titanium/iron precursors in sealed polyethylene bottles in the BaTiO3 and BaFe12O19 systems, respectively. While crystalline BaTiO3 forms relatively fast within a few hours, formation of fully crystalline and stoichiometric BaFei20i9 require considerably longer reaction times up to several weeks and strongly dependent on the Ba:Fe ratio of the precursors. The structural and compositional evaluation of the nanophase powders were studied by XRD and TEM techniques.

Preparation and Modification of Nano-Li4Ti5O12 Anode Material

2011 ◽  
Vol 347-353 ◽  
pp. 3439-3442 ◽  
Author(s):  
Ying Qiu Xu ◽  
Guang Chuan Liang ◽  
Li Wang
Keyword(s):  
Hydrothermal Reaction ◽  
Carbon Sources ◽  
Lithium Titanate ◽  
X Ray Diffraction ◽  
Reaction Method ◽  
X Ray ◽  
Structure Morphology ◽  
Discharge Capacities ◽  
Uniform Particle Size ◽  
Charge Discharge

The spinel nano-Li4Ti5O12 was prepared by hydrothermal reaction method. The crystal structure, morphology and charge/discharge capacities were characterized by powder X-ray diffraction and Scanning electron microscopy and program-controlled tester respectively. It showed that lithium titanate synthesized by the direct hydrothermal method has a uniform particle size distribution of about 100nm in cubic shape. Investigated the influence of different carbon sources on the structure and electrochemical properties. It was found that the discharge capacities could reach 172.2, 159.8, 156.2 and 148.3mAh/g at 0.2C, 1C, 2C and 5C rates, respectively.

scholarly journals Groundwater Remediation Using Biological And Photocatalytic Methods

2015 ◽  
Vol 43 (1) ◽  
pp. 39-44 ◽  
Author(s):  
Sándor Guba ◽  
Viola Somogyi ◽  
Erzsébet Szabóné Bárdos
Keyword(s):  
Activated Sludge ◽  
Active Ingredient ◽  
Biological Treatment ◽  
Groundwater Remediation ◽  
Uv Light ◽  
Transport Modelling ◽  
Sludge Treatment ◽  
Treatment Methods ◽  
Laboratory Conditions ◽  
Preliminary Information

Abstract The degradability of two commercially available pesticides was studied using heterogeneous photocatalytic and activated sludge treatment methods. The first pesticide contained 5% quizalofop-P-ethyl as an active ingredient and petroleum naphtha as a solvent, the latter causing difficulties both in photocatalytic and biological treatment methods. The active ingredient of the second compound was acetamiprid. The photocatalysis proved to be effective both under laboratory conditions (using UV light) and when exposed to sunlight, but the pesticides remained stable during the employed biological treatment. Preliminary information on its behaviour in soil was obtained from transport modelling.

A Short Review of Wastewater Biological Treatment at Low C/N ratio

2014 ◽  
Vol 962-965 ◽  
pp. 1490-1494
Author(s):  
Jian Zheng Li ◽  
Shuai Shi
Keyword(s):  
Carbon Source ◽  
Nitrogen Removal ◽  
Biological Treatment ◽  
Carbon Sources ◽  
Short Review ◽  
Biological Nitrogen Removal ◽  
Removal Processes ◽  
Biological Nitrogen ◽  
Low Nitrogen ◽  
Wastewater Biological Treatment

Low nitrogen removal efficiency caused by the lack of carbon source in low C/N ratio wastewater restricts the wastewater biological treatment. Advances in wastewater biological treatment at low C/N ratio are reviewed in the paper from three aspects, including modifying traditional biological nitrogen removal process, developing novel biological nitrogen removal processes and optimizing traditional carbon source and developing new types of carbon sources. The mechanisms, advantages, and applications of these processes are also summarized and analyzed.

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