Cooking emissions show a strong dependence on cooking styles and parameters. Measurements of the average ultrafine particle (UFP) concentration, PM2.5 and black carbon concentrations emitted by cooking activities ranged from 1.34 × 104 to 6.04 × 105 particles/cm3, 10.0 to 230.9 μg/m3 and 0.1 to 0.8 μg/m3, respectively. Lower UFP concentrations were observed during boiling, while higher levels were emitted during frying. The highest UFP concentrations were observed when using a gas stove at high temperature with the kitchen exhaust fan turned off. The observed UFP profiles were similar in the kitchen and in another room, with a lag of approximately 10 min.

Formaldehyde (HCHO) adsorption isotherms were developed for the first time on three activated carbons representing one activated carbon fiber (ACF) cloth, one all-purpose granular activated carbon (GAC), and one GAC commercially promoted for gas-phase HCHO removal. The three activated carbons were evaluated for HCHO removal in the low-ppm(v) range and for water vapor adsorption from relative pressures of 0.1-0.9 at 26 °C where, according to the IUPAC isotherm classification system, the adsorption isotherms observed exhibited Type V behavior. A Type V adsorption isotherm model recently proposed by Qi and LeVan (Q-L) was selected to model the observed adsorption behavior because it reduces to a finite, nonzero limit at low partial pressures and it describes the entire range of adsorption considered in this study. The Q-L model was applied to a polar organic adsorbate to fit HCHO adsorption isotherms for the three activated carbons. The physical and chemical characteristics of the activated carbon surfaces were characterized using nitrogen adsorption isotherms, X-ray photoelectron spectroscopy (XPS), and Boehm titrations. At low concentrations, HCHO adsorption capacity was most strongly related to the density of basic surface functional groups (SFGs), while water vapor adsorption was most strongly influenced by the density of acidic SFGs.

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Determination of the adsorption properties of novel activated carbons is important to develop new air quality control technologies that can solve air quality problems in a more environmentally sustainable manner. Equilibrium adsorption capacities and heats of adsorption are important parameters for process analysis and design. Experimental adsorption isotherms were thus obtained for relevant organic vapors with activated carbon fiber cloth (ACFC) and coal-derived activated carbon adsorbents (CDAC). The Dubinin-Astakhov (DA) equation was used to describe the adsorption isotherms. The DA parameters were analytically and experimentally shown to be temperature independent. The resulting DA equations were used with the Clausius-Clapeyron equation to analytically determine the isosteric heat of adsorption (deltaHS) of the adsorbate-adsorbent systems studied here. ACFC showed higher adsorption capacities for organic vapors than CDAC. DeltaHS values for the adsorbates were independent of the temperature for the conditions evaluated. DeltaHS values for acetone and benzene obtained in this study are comparable with values reported in the literature. This is the first time that deltaHS values for organic vapors and these adsorbents are evaluated with an expression based on the Polanyi adsorption potential and the Clausius-Clapeyron equation.

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