Publications

@article{WEI2018223,

title = {Influence of indoor environmental factors on mass transfer parameters and concentrations of semi-volatile organic compounds},

author = {Wenjuan Wei and Corinne Mandin and Olivier Ramalho},

url = {http://www.sciencedirect.com/science/article/pii/S0045653517320428},

doi = {https://doi.org/10.1016/j.chemosphere.2017.12.072},

issn = {0045-6535},

year  = {2018},

date = {2018-01-01},

journal = {Chemosphere},

volume = {195},

pages = {223 - 235},

abstract = {Semi-volatile organic compounds (SVOCs) in indoor environments can partition among the gas phase, airborne particles, settled dust, and available surfaces. The mass transfer parameters of SVOCs, such as the mass transfer coefficient and the partition coefficient, are influenced by indoor environmental factors. Subsequently, indoor SVOC concentrations and thus occupant exposure can vary depending on environmental factors. In this review, the influence of six environmental factors, i.e., indoor temperature, humidity, ventilation, airborne particle concentration, source loading factor, and reactive chemistry, on the mass transfer parameters and indoor concentrations of SVOCs was analyzed and tentatively quantified. The results show that all mass transfer parameters vary depending on environmental factors. These variations are mostly characterized by empirical equations, particularly for humidity. Theoretical calculations of these parameters based on mass transfer mechanisms are available only for the emission of SVOCs from source surfaces when airborne particles are not present. All mass transfer parameters depend on the temperature. Humidity influences the partition of SVOCs among different phases and is associated with phthalate hydrolysis. Ventilation has a combined effect with the airborne particle concentration on SVOC emission and their mass transfer among different phases. Indoor chemical reactions can produce or eliminate SVOCs slowly. To better model the dynamic SVOC concentration indoors, the present review suggests studying the combined effect of environmental factors in real indoor environments. Moreover, interactions between indoor environmental factors and human activities and their influence on SVOC mass transfer processes should be considered.},

keywords = {Emission, Mass transfer, Modeling, Partition, SVOCs},

pubstate = {published},

tppubtype = {article}

}

@article{LIU2016283,

title = {Characterizing the equilibrium relationship between DEHP in PVC flooring and air using a closed-chamber SPME method},

author = {Cong Liu and Yinping Zhang},

url = {http://www.sciencedirect.com/science/article/pii/S0360132315301372},

doi = {https://doi.org/10.1016/j.buildenv.2015.09.028},

issn = {0360-1323},

year  = {2016},

date = {2016-01-01},

journal = {Building and Environment},

volume = {95},

pages = {283 - 290},

abstract = {The di-(2-ethylhexyl) phthalate (DEHP) concentration in the air immediately adjacent to a polyvinyl chloride (PVC) flooring surface, y0 (μg/m3), has been identified as one of the critical parameters governing the emission process and consequent exposure. At room temperature and below, the relationship between y0 and the vapor pressure of pure DEHP (Psat) is still unclear. Few studies have been conducted to examine the influence of the mass fraction of DEHP in PVC on the relationship. In this study a new closed-chamber solid phase microextraction (SPME) method is developed to characterize ratio of y0 to Psat at 23 °C. This method avoids the artifact from wall-loss of sampling lines and of the thermal desorption system, in contrast to ventilated-chamber methods. Results show that at 23 °C y0 is significantly lower than the vapor pressure of pure DEHP. When the mass fraction of DEHP in PVC flooring increases from 13% to 23%, y0/Psat is increased by 7.2%, similar to what is reported in the literature. The sorption capacity of SPME stainless steel (SS) rods differs by up to 104%, although they are all made of SS. Based on error analysis, strategies are recommended to improve the precision and time efficiency. The method developed here should work for other SVOC-polymer systems.},

keywords = {Emission, Indoor air quality (IAQ), Mass transfer, Persistent organic pollutants (POPs), Semivolatile organic compound (SVOC)},

pubstate = {published},

tppubtype = {article}

}

@article{ZHANG201365,

title = {Convective mass transfer and pressure drop correlations for cross-flow structured hollow fiber membrane bundles under low Reynolds numbers but with turbulent flow behaviors},

author = {Li-Zhi Zhang and Zhen-Xing Li},

url = {http://www.sciencedirect.com/science/article/pii/S037673881300104X},

doi = {https://doi.org/10.1016/j.memsci.2013.01.058},

issn = {0376-7388},

year  = {2013},

date = {2013-01-01},

journal = {Journal of Membrane Science},

volume = {434},

pages = {65 - 73},

abstract = {Cross-flow structured hollow fiber membrane bundles where the fibers are arranged either in inline or in staggered arrays are investigated for their bundle side convective mass transfer and pressure drop characteristics. A high speed hot wire anemometry is used to validate the turbulent flow behavior in the bundle at low Reynolds numbers. A mathematical model for the turbulent fluid flow and convective mass transfer across the bundle under uniform mass boundary conditions is set up, which is then validated by an air humidification test. With the validated model, the Sherwood numbers and friction factors across the bundle are obtained for different fiber arrangements, pitch to diameter ratios, and Reynolds numbers. Correlations are then proposed to estimate the friction factors and Sherwood numbers across the bundles with various parameters. It is found that compared to the previous researches and the available correlations, the present results are more appropriate for the cross flow hollow fiber membrane bundles that are usually operated under low Reynolds numbers from 100 to 500, but have turbulent flow behaviors.},

keywords = {Cross flow, Hollow fiber membrane bundle, Mass transfer, Structured, Turbulent flow},

pubstate = {published},

tppubtype = {article}

}

@article{MIN2010185,

title = {Evaluation of moisture diffusivities in various membranes},

author = {Jingchun Min and Teng Hu and Xiaowei Liu},

url = {http://www.sciencedirect.com/science/article/pii/S0376738810003108},

doi = {https://doi.org/10.1016/j.memsci.2010.04.019},

issn = {0376-7388},

year  = {2010},

date = {2010-01-01},

journal = {Journal of Membrane Science},

volume = {357},

number = {1},

pages = {185 - 191},

abstract = {An experimental set-up was designed and constructed to investigate the moisture permeation through a membrane. The test section consists mainly of an airflow channel, a membrane, and a water tank, with the membrane being sandwiched between the channel and water tank. An air gap exists between the membrane and the water in the water tank to avoid any possible wetting of the membrane by the water. Moisture transfers from the water to the airstream in the channel through the air gap and membrane. The moisture transfer process was described using a serial resistance model, which involves the convective moisture resistance in the channel, the moisture resistance through membrane, and the moisture resistance caused by the air gap. Special methods were developed to determine the convective and air gap resistances, with the membrane resistance obtained by subtracting such two resistances from the total resistance. Tests were conducted on three membranes including the PVDF (poly vinylidene fluoride), PES (poly ether sulfone) and cellulose membranes for airflow rates from 3.0 to 5.0l/min, yielding Reynolds numbers from 117 to 195. The results showed that the moisture diffusivities in these membranes were in the order of 10−7 to 10−6kg/ms, with the PVDF yielding the maximum diffusivity and the PES giving the minimum diffusivity.},

keywords = {Diffusivity, Mass transfer, Membrane, Membrane resistance, Water vapor},

pubstate = {published},

tppubtype = {article}

}

@article{LI20061317,

title = {A physically-based model for prediction of VOCs emissions from paint applied to an absorptive substrate},

author = {Feng Li and Jianlei Niu and Lizhi Zhang},

url = {http://www.sciencedirect.com/science/article/pii/S0360132305001939},

doi = {https://doi.org/10.1016/j.buildenv.2005.05.026},

issn = {0360-1323},

year  = {2006},

date = {2006-01-01},

journal = {Building and Environment},

volume = {41},

number = {10},

pages = {1317 - 1325},

abstract = {Paints are widely used in residential and commercial buildings. The surface areas covered by this kind of coatings are usually very large. The volatile organic compounds (VOCs) emissions from such kind of materials will affect indoor air quality decisively. A relatively simple but physically-based model was developed to simulate VOCs emissions from paints. The model parameters have distinct physical meanings and thus the model is easy to scale up. The field and laboratory emission cell (FLEC) was used to investigate the VOCs emissions from commercially available water-based emulsion paint. Totally 23 individual VOCs were detected and quantified, the most abundant VOC was 1-ethyl-3-methylbenzene. Test data were used to obtain model parameters and to validate the proposed model. Good agreements between experimental data and model predictions were evidenced. Paints applied on two different substrates aluminium and particle board were simulated. Results indicated that real substrates like particle board would act like a ‘sponge’, which lowers the peak concentration but prolongs the presence of VOCs from the applied paint.},

keywords = {Building material, Emission, Field and laboratory emission cell (FLEC), Indoor air quality, Mass transfer, Volatile organic compounds},

pubstate = {published},

tppubtype = {article}

}

@article{ZHANG2004523,

title = {Modeling VOCs emissions in a room with a single-zone multi-component multi-layer technique},

author = {L Z Zhang and J L Niu},

url = {http://www.sciencedirect.com/science/article/pii/S0360132303002439},

doi = {https://doi.org/10.1016/j.buildenv.2003.10.005},

issn = {0360-1323},

year  = {2004},

date = {2004-01-01},

journal = {Building and Environment},

volume = {39},

number = {5},

pages = {523 - 531},

abstract = {Building envelopes are usually comprised of several layers with different materials, which can significantly affect volatile organic compounds (VOCs) concentrations in indoor environments. These layers may act as source and sink alternatively depending on the different sorption and diffusion potentials. The model proposed here is a single zone one and it considers the different emission properties of building components, namely, the different sorption and diffusion characteristics of the side walls, the floor and the ceiling. In addition, each component comprises of several layers, which represents different construction materials. Two VOCs, ethyl acetate and n-octane, representing polar and nonpolar compounds respectively, are modeled to study the emission profiles in a room with several building materials. The effects of various construction materials, and the different convective mass transfer coefficients between room air and different building components, on the emission characteristics are investigated.},

keywords = {Emissions, Indoor air quality, Mass transfer, VOCs},

pubstate = {published},

tppubtype = {article}

}

@article{ZHANG20032415,

title = {Mass transfer of volatile organic compounds from painting material in a standard field and laboratory emission cell},

author = {L Z Zhang and J L Niu},

url = {http://www.sciencedirect.com/science/article/pii/S0017931003000127},

doi = {https://doi.org/10.1016/S0017-9310(03)00012-7},

issn = {0017-9310},

year  = {2003},

date = {2003-01-01},

journal = {International Journal of Heat and Mass Transfer},

volume = {46},

number = {13},

pages = {2415 - 2423},

abstract = {The field and laboratory emission cell (FLEC) is becoming a standard method of characterizing pollutant emissions from building materials. It is significant to use the emission profiles from FLEC to scale the emissions of building materials in real buildings. The dynamics of mass transfer in such an FLEC are the key to perform this task. In this study, the mass transfer mechanisms of the total volatile organic compounds from a wet painting in an FLEC are experimentally and numerically investigated. A three-dimensional mass transfer model, which takes into account the convective mass transfer between the material and the air, the diffusion in the paint film and in the substrate, is developed. The emissions from a water-based emulsion paint are quantified to assess the model. The concentration fields in the film and substrate are calculated to demonstrate the processes of internal volatile organic compounds diffusion.},

keywords = {Field and laboratory emission cell (FLEC), Indoor air quality, Mass transfer, VOCs},

pubstate = {published},

tppubtype = {article}

}

@article{ZHANG2003939,

title = {Effects of substrate parameters on the emissions of volatile organic compounds from wet coating materials},

author = {L Z Zhang and J L Niu},

url = {http://www.sciencedirect.com/science/article/pii/S0360132303000325},

doi = {https://doi.org/10.1016/S0360-1323(03)00032-5},

issn = {0360-1323},

year  = {2003},

date = {2003-01-01},

journal = {Building and Environment},

volume = {38},

number = {7},

pages = {939 - 946},

abstract = {Solvent-based interior coating materials have long been recognized as a major source of volatile organic compounds (VOCs) in the indoor environment. In the emission process, substrate acts as a secondary source. The sink effects are studied with a detailed mass transfer model considering convective mass transfer in air streams, the VOCs diffusions in painting film, and the sorption and diffusions of VOCs in substrate. The model is proposed and validated by the emission profiles of a water-based emulsion paint in a standard field and laboratory emission cell. The focus is on the role the substrate plays in the emission process. The effects of the substrate parameters, such as the substrate diffusivity and sorption characteristics, on the emission profiles are investigated. This is helpful in exposure control through both selecting healthy materials and proper ventilations.},

keywords = {FLEC (Field and laboratory emission cell), Indoor air quality, Mass transfer, VOCs},

pubstate = {published},

tppubtype = {article}

}

@article{ZHANG200391,

title = {Laminar fluid flow and mass transfer in a standard field and laboratory emission cell},

author = {L Z Zhang and J L Niu},

url = {http://www.sciencedirect.com/science/article/pii/S0017931002002387},

doi = {https://doi.org/10.1016/S0017-9310(02)00238-7},

issn = {0017-9310},

year  = {2003},

date = {2003-01-01},

journal = {International Journal of Heat and Mass Transfer},

volume = {46},

number = {1},

pages = {91 - 100},

abstract = {The field and laboratory emission cell (FLEC) is becoming a standard method of characterizing pollutant emissions from building materials. Based on this method, the material and the inner surface of the FLEC cap form a cone-shaped cavity. The airflow is distributed radially inward over the test surface through a slit in a circular-shaped channel at the perimeter of the chamber. After mass transfer, the air is exhausted through an outlet in the center. Usually, emission rate profiles are obtained using such cells. However, the local convective mass transfer coefficients are now needed. In this study, laminar fluid flow and mass transfer in a standard FLEC are investigated. The velocity field and moisture profiles are obtained by solving Navier–Stokes equations numerically. The whole geometry, including the air inlet and outlet, channel, air slit, and emission space, are included in the numerical modeling domain. The mean convective mass transfer coefficients are calculated and compared with the experimental data. In the test, distilled water is used in the FLEC lower chamber to substitute the emission surface. Mass transfer data are obtained by calculating humidity differences between the inlet and outlet of a gas stream flowing through the FLEC. The study concentrates on assessing the variations of velocity and humidity profiles, as well as convective mass transfer coefficients, in the cell.},

keywords = {Convection, Field and laboratory emission cell, Indoor air quality, Mass transfer},

pubstate = {published},

tppubtype = {article}

}