Investigation of the treatability of the primary indoor volatile organic compounds on activated carbon fiber cloths at typical indoor concentrations.

Volatile organic compounds (VOCs) are a major concern for indoor air pollution because of the impacts on human health. In recent years, interest has increased in the development and design of activated carbon filters for removing VOCs from indoor air. Although extensive information is available on sources, concentrations, and types of indoor VOCs, there is little or no information on the performance of indoor air adsorption systems for removing low concentrations of primary VOCs.

Predicting influent estradiol and estrone concentrations for wastewater treatment facilities.

An externally validated model was developed to predict influent concentrations of natural estrogens at municipal wastewater plants. The model kinetic constant for the first-order biotransformation of estradiol into estrone, k(E2), was calculated as 0.030 hour(-1) (ranging from -0.

Adsorption and regeneration on activated carbon fiber cloth for volatile organic compounds at indoor concentration levels.

There are increasing concerns about indoor volatile organic compounds (VOCs) regarding their health effects and frequent occurrence. Adsorption using granular activated carbon (GAC) is a safe methodology for removing VOCs from indoor air. Although GAC has been widely used to remove VOCs from indoor air, the use of activated carbon fiber cloth (ACFC) is a promising substitute to the conventional activated carbon because of its regenerative properties; hence, this paper provides promising results for the application of ACFC as a regenerative adsorbent for the removal of VOCs from indoor air.

Mathematical model for photocatalytic destruction of organic contaminants in air.

Photocatalytic oxidation (PCO) was investigated in a bench-scale reactor for the abatement of two airborne organic contaminants: toluene and ethanol. A mathematical model that includes the impacts of light intensity, initial contaminant concentration, catalyst thickness, and relative humidity (RH) on the degradation of organic contaminants in a photocatalytic reactor was developed to describe this process. The commercially available catalyst Degussa-PtTiO2 was selected to compare with the MTU-PtTiO2-350 catalyst, which was synthesized by the sol-gel process, platinized, and calcined at 350 degrees C.

Simulating the performance of fixed-bed granular activated carbon adsorbers: removal of synthetic organic chemicals in the presence of background organic matter.

Granular activated carbon (GAC) adsorption is an effective treatment technology for the removal of synthetic organic chemicals (SOCs) from drinking water supplies. This treatment process can be expensive if not properly designed. Application of mathematical models is an attractive method to evaluate the impact of process variables on process design and performance.

Preparation of a novel TiO2-based p-n junction nanotube photocatalyst.

TiO2 nanotube semiconductors contain free spaces in their interior that can be filled with active materials such as chemical compounds, enzymes, and noble metals, giving them a fundamental advantage over colloids. Although the unique shape of semiconductor nanotubes makes them promising for a range of potential applications, significant developmental research is required. In this research, a novel TiO2 nanotube photocatalyst was prepared that has a p-n junction.

Remediation of MTBE from drinking water: air stripping followed by off-gas adsorption.

The widespread use of methyl tertiary butyl ether (MTBE) as an oxygenate in gasoline has resulted in the contamination of a large number of ground and surface water sources. Even though air stripping has been proven to be an effective treatment technology for MTBE removal, off-gas treatment often is required in conjunction with it. This study evaluated the combined treatment technologies of air stripping followed by off-gas adsorption on a pilot scale for the treatment of MTBE-contaminated water.

Application of an isothermal, three-phase catalytic reactor model to predict unsteady-state fixed-bed performance.

CatReac, a three-phase catalytic mathematical model, was developed for analysis and optimization of the volatile reactor assembly used in International Space Station water processor. This wet oxidation process is used to remove low molecular weight contaminants such as acetic acid, acetone, ethanol, 1-propanol, 2-propanol, and propionic acid, which are not removed by the other treatment processes. The Langmuir-Hinshelwood (Hinshelwood, C.

Removal and Destruction of Organic Contaminants in Water Using Adsorption, Steam Regeneration, and Photocatalytic Oxidation: A Pilot-Scale Study.

The overall objective of this pilot-scale study is to investigate the technical feasibility of the removal and destruction of organic contaminants in water using adsorption and photocatalytic oxidation. The process consists of two consecutive operational steps: (1) removal of organic contaminants using fixed-bed adsorption; and (2) regeneration of spent adsorbent using photocatalysis or steam, followed by decontamination of steam condensate using photocatalysis. The pilot-scale study was conducted to evaluate these options at a water treatment plant in Wausau (Wisconsin) for treatment of groundwater contaminated with tetrachloroethene (PCE), trichloroethene (TCE), cis-dichloroethene (cis-DCE), toluene, ethylbenzene (EB), and xylenes.