Removal Efficiency of Organic Substance in Municipal Sludge by Supercritical Water Oxidation

In this study efficiency of organic matter in municipal wastewater sludge treated by supercritical water is investigated. Influences of main reaction parameters, including temperature (380~500°C), pressure (23-30 MPa), residence time (1-10 min), oxidant dose (100%-200%), were evaluated. Orthogonal Array design was applied in order to consider each parameters impact on COD removal. Study results indicate that 97.89% of COD in the sludge sample can be removed in 10min at 500°C, 30MPa and 200% H2O2oxidant excess dose. Temperature, pressure, resident time are main factors to affect the reaction, while oxidant dose has a little effect on removal of COD in municipal wastewater sludge. The conclusion is the organic matter in municipal wastewater sludge can be removed effectively by super critical water oxidation.

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Supercritical water oxidation for treatment of wastewater sludge and recalcitrant organic contaminants

Environmental Technology & Innovation ◽

10.1016/j.eti.2020.100728 ◽

2020 ◽

Vol 18 ◽

pp. 100728 ◽

Cited By ~ 1

Author(s):

Ze Yan ◽

Banu Örmeci ◽

You Han ◽

Jinli Zhang

Keyword(s):

Supercritical Water ◽

Water Oxidation ◽

Organic Contaminants ◽

Wastewater Sludge ◽

Supercritical Water Oxidation

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Decomposition of Municipal Sludge by Supercritical Water Oxidation.

JOURNAL OF CHEMICAL ENGINEERING OF JAPAN ◽

10.1252/jcej.30.813 ◽

1997 ◽

Vol 30 (5) ◽

pp. 813-818 ◽

Cited By ~ 30

Author(s):

Motonobu Goto ◽

Takatsugu Nada ◽

Satoshi Kawajiri ◽

Akio Kodama ◽

Tsutomu Hirose

Keyword(s):

Supercritical Water ◽

Water Oxidation ◽

Supercritical Water Oxidation ◽

Municipal Sludge

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Research on the Corrosion Behavior of Nickel Base Alloy in Municipal Sludge Treated by Supercritical Water Oxidation

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1010-1012.220 ◽

2014 ◽

Vol 1010-1012 ◽

pp. 220-224 ◽

Cited By ~ 1

Author(s):

Hong Ma ◽

Shu Zhong Wang ◽

Mei Gao ◽

Sheng Wen

Keyword(s):

Corrosion Rate ◽

Corrosion Behavior ◽

Supercritical Water ◽

Water Oxidation ◽

Base Alloy ◽

Supercritical Water Oxidation ◽

Nickel Base Alloy ◽

Municipal Sludge ◽

Temperature Zone ◽

Nickel Base

The corrosion behavior of Nickel base alloy was studied in municipal sludge treated by supercritical water oxidation (SCWO). The results showed that the corrosion rate of Nickel-base alloy Inconel600 in the temperature zone under 460°C is smaller, the surface oxide were mainly Cr2O3. The corrosion rate of Nickel-base alloy Inconel625 in the supercritical temperature zone is smaller, it formed more easily protective layers containing element Ni (main containing NiO and Ni (OH)2) and had good heat resistance at higher temperature.

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Parameter Optimization of Municipal Sludge Treated by Supercritical Water Oxidation Process

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1010-1012.693 ◽

2014 ◽

Vol 1010-1012 ◽

pp. 693-698

Author(s):

Mei Gao ◽

Shu Zhong Wang ◽

Hong Ma

Keyword(s):

Total Nitrogen ◽

Residence Time ◽

Reaction Temperature ◽

Supercritical Water ◽

Water Oxidation ◽

Oxidation Process ◽

Removal Rate ◽

Supercritical Water Oxidation ◽

Municipal Sludge ◽

Optimum Reaction

Supercritical water oxidation process can effectively degrade the total nitrogen in municipal sludge. In order to obtain the optimum parameters of municipal sludge treated by supercritical water oxidation, this article selected the total nitrogen removal rate as the evaluation value, and used response surface methodology to optimize the parameters of sludge treatment by supercritical water oxidation, the parameters including temperature, pressure, residence time and oxidation coefficient. The results show that the reaction temperature, pressure and residence time exist interaction, and the influence degree of parameters is: pressure > reaction temperature > reaction retention time; The optimum reaction conditions are as follows: reaction temperature 539 °C, pressure 27 MPa, residence time 434 s, and oxidation coefficient 2.16, under these conditions, the total nitrogen decreasing efficiency can reach 74.12%.

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Corrosion characteristic comparisons of ZrO2-, TiO2-coated and uncoated 316 stainless steel samples in supercritical water oxidation of municipal sludge

The Journal of Supercritical Fluids ◽

10.1016/j.supflu.2019.104663 ◽

2020 ◽

Vol 155 ◽

pp. 104663 ◽

Cited By ~ 1

Author(s):

Donghai Xu ◽

Shuwei Guo ◽

Zhijiang Ma ◽

Yanhui Li ◽

Wenjun Kuang ◽

...

Keyword(s):

Stainless Steel ◽

Supercritical Water ◽

Water Oxidation ◽

Supercritical Water Oxidation ◽

Municipal Sludge ◽

Corrosion Characteristic ◽

316 Stainless Steel

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Analysis of the Energy Flow in a Municipal Wastewater Treatment Plant Based on a Supercritical Water Oxidation Reactor Coupled to a Gas Turbine

Processes ◽

10.3390/pr9071237 ◽

2021 ◽

Vol 9 (7) ◽

pp. 1237

Author(s):

Fidel A. Mato ◽

Mar Peña ◽

Yoana García-Rodríguez ◽

María-Dolores Bermejo ◽

Ángel Martín

Keyword(s):

Gas Turbine ◽

Supercritical Water ◽

Water Oxidation ◽

Municipal Wastewater ◽

Energy Content ◽

Treatment Plant ◽

Supercritical Water Oxidation ◽

Treatment Unit ◽

Oxidation Reactor ◽

Sludge Production

Biological municipal wastewater treatments lead to high sludge generation and long retention times, and the possibilities for recovery of the energy content of the input waste stream are very limited due to the low operating temperature. As an alternative, we propose a sequence of exclusively physicochemical, non-biological stages that avoid sludge production, while producing high-grade energy outflows favoring recovery, all in shorter times. Ultrafiltration and evaporation units provide a front-end concentration block, while a supercritical water oxidation reactor serves as the main treatment unit. A new approach for energy recovery from the effluent of the reactor is proposed, based on its injection in a gas turbine, which presents advantages over simpler direct utilization methods from operational and efficiency points of view. A process layout and a numerical simulation to assess this proposal have been developed. Results show that the model process, characterized with proven operating parameters, found a range of feasible solutions to the treatment problem with similar energy costs, at a fast speed, without sludge production, while co-generating the municipality’s average electricity consumption.

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