Effects of surfactant injection position on the airflow pattern and contaminant removal efficiency of surfactant-enhanced air sparging

The paper presents a mechanistic/deterministic model for simulation of mass removal during air sparging. From the point of numerical modeling, there are two issues considering air sparging: modeling of air flow and distribution and modeling of mass transport and transfer. Several processes, which are commonly neglected, such as air channeling and pollutant advection by the water phase, are taken into account. The numerical model presented in this paper considers all relevant for mass transfer during the air sparging. Model includes hydrodynamics of air and water phase; calculated air volume content is divided into a number of air channels surrounded by the water phase, which is divided into two compartments. First compartment is immobile and it is in contact with air phase, while the second compartment is mobile. This “mobile-immobile” formulation is a common approach for description of solute transport by groundwater. Mass transfer between two water compartments is modeled as a first order kinetic, where the mass transfer coefficient, representing diffusion and advection in the water phase towards the air channels, is parameter needed to be calibrated. Sorption for both water compartments is considered. The adopted model of contaminant evaporation at the air-water interface is verified by comparison with experimental results available from published sources. Model is used for simulation of two-dimensional air sparging laboratory experiment. Good overall agreement is observed. It is showed that the efficiency of air sparging can be influenced by natural groundwater flow.

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Study on Wastewater Contaminant Removal Efficiency by Carbon Fiber Ecological Grass

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.838-841.2300 ◽

2013 ◽

Vol 838-841 ◽

pp. 2300-2305 ◽

Cited By ~ 1

Author(s):

Hao Guo ◽

Wei Fang Ma ◽

Jian Dong Ye ◽

Chang Jiang Kou

Keyword(s):

Wastewater Treatment ◽

Carbon Fiber ◽

Removal Efficiency ◽

Good Choice ◽

Contaminant Removal ◽

Research Results ◽

Stirring Rate ◽

N Removal

The aim of this study is to investigate the contaminant removal efficiency in wastewater when disposed by carbon fiber ecological grass. The paper analyzed the TN, TP, CODMn, NH4+-N and SS removal efficiency when used different dosage of carbon fiber ecological grass. The research results indicated that the contaminant removal efficiency at pH=8 is higher than pH=6, 7 and 9. When DO between 5.6 and 8, the TN, TP and NH4+-N removal efficiency has a highest level, the removal efficiency is 83.91%, 68.16% and 83.3% respectively. When DO between 8.1 and 10.7, the CODMn removal efficiency has a highest level, the removal efficiency is 57.93%. The stirring rate is important to the contaminant adsorption and removal. Consequently, selecting carbon fiber ecological grass in wastewater treatment is a good choice.

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Impacts of Changing Operational Parameters of In Situ Chemical Oxidation (ISCO) on Removal of Aged PAHs from Soil

Journal of Advanced Oxidation Technologies ◽

10.1515/jaots-2012-0223 ◽

2012 ◽

Vol 15 (2) ◽

Cited By ~ 1

Author(s):

Paula Cajal-Mariñosa ◽

Ruth G. de la Calle ◽

F. Javier Rivas ◽

Tuula Tuhkanen

Keyword(s):

Hydrogen Peroxide ◽

Removal Efficiency ◽

Contaminated Soil ◽

Chemical Oxidation ◽

Contaminant Removal ◽

Operational Parameters ◽

In Situ Chemical Oxidation ◽

Different Types ◽

Wood Impregnation

AbstractThe removal efficiency of two different types of peroxide addition, catalyzed hydrogen peroxide (CHP) and sodium percarbonate (SPC) were compared on a highly PAH-contaminated soil from a wood impregnation site. In an attempt to simulate real in situ reagents delivery, experiments have been carried out in acrylic columns. The main parameters affecting contaminant removal were the reagent’s temperature and the total addition of peroxide (g

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