Removal Of Indoor Air Pollutants Research Articles

Characteristics of potted plants for removing offensive odors

Plants have the capability to remove indoor air pollutants and furthermore to decompose odor molecules in an indoor environment. Hydrogen sulfide (H 2S), ammonia (NH 3) and methyl mercaptan (CH 3SH) are the three main offensive odors in a nursing home. It is strongly desired to develop an effective method for reducing those substances. In this study, the pollutant-removing characteristics of a potted plant for three substances, ammonia, formaldehyde and acetone, are examined using a tin oxide gas sensor. As for the results, it became obvious that the removing characteristics for ammonia gas could be indicated using an approximate function of y=a exp(−bx)+c . In this function, the coefficient b stands for the removing effect and c means the offset level of sensor output. The coefficient a stands for the intercept from that level. It can indicate the number of pots and the kind of plants to maintain the clean air quality in an indoor environment. The pothos plant is very available for putting this to practical use.

Physical properties and photocatalytic performance of TiO2 coated stainless steel plate

This research was conducted for the development of TiO2 thin film coated stainless steel useful in environmental and sanitary fields such as removal of indoor air pollutants and prevention of harmful microorganisms in the kitchen and bathroom. For this purpose, the research was focused on the examination of physical properties of coated surfaces as well as the photocatalytic performance of the steel plates. The coated steel’s cohesiveness and anti-corrosion effect were good enough to be used even in the hard environments. To test the photocatalytic performance of the TiO2 thin film coated stainless steel plate, photodegradations ofm-xylene, a typical air pollutant produced by automobiles, andE. coli, under 365 nm UV irradiation, were conducted. The TiO2 coated stainless steel plate considerably enhanced the degradation efficiencies ofm-xylene andE. coli.

Impact of Combined Dilution and Pressurisation Effects of Ventilation Air on Indoor Contaminant Concentration

When outdoor air is the main source of pollutants indoors, mechanical air ventilation can be viewed as having two fronts of action in controlling indoor air quality. The first is its capacity to remove indoor air pollutants by dilution, and the second is its capability to prevent, through its pressurisation effect, the pollutant source (i.e. untreated outdoor air) from infiltrating, through the building envelope, to the occupied space. This paper discusses the impact of combined dilution and pressurisation potentials of ventilation air on indoor contaminant concentration when outdoor air is the main source of pollutants. Utilising an airflow model in conjunction with a one-compartment indoor air quality model, contaminant concentration behaviour within a single zone enclosure is predicted at various enclosure air leakage, system characteristics and pressurisation levels. Results from this study are indicative of the appreciable impact of the pressurisation effect of ventilation air which needs to be considered for a better assessment of ventilation air effectiveness and further enhancement of indoor air quality control.

Impact of Combined Dilution and Pressurisation Effects of Ventilation Air on Indoor Contaminant Concentration

When outdoor air is the main source of pollutants indoors, mechanical air ventilation can be viewed as having two fronts of action in controlling indoor air quality. The first is its capacity to remove indoor air pollutants by dilution, and the second is its capability to prevent, through its pressurisation effect, the pollutant source (i.e. untreated outdoor air) from infiltrating, through the building envelope, to the occupied space. This paper discusses the impact of combined dilution and pressurisation potentials of ventilation air on indoor contaminant concentration when outdoor air is the main source of pollutants. Utilising an airflow model in conjunction with a one-compartment indoor air quality model, contaminant concentration behaviour within a single zone enclosure is predicted at various enclosure air leakage, system characteristics and pressurisation levels. Results from this study are indicative of the appreci able impact of the pressurisation effect of ventilation air which needs to be considered for a better assessment of ventilation air effectiveness and further enhancement of indoor air quality control.

Control of tobacco smoke and odors using discharge plasma reactor

Contamination of indoor environment relating to the Sick-Building Syndrome has been attracting a great deal of attention recently. Tobacco smoke components are representative of a wide range of pollutants found in indoor air. There is a strong needs of keeping indoor air clean, so an experimental study on the removal of indoor air pollutants has been carried out using three types (dry, semi-wet, wet) of plasma reactor and power source (AC 60Hz, AC 18kHz square wave pulse). The wet type plasma process is proved to be an efficient means for cleaning of indoor air.

Analysis of errors associated with passive ventilation measurement techniques

In small building where ventilation is the primary mechanism for removing indoor air pollutants, interest in converting the resulting energy load on the heating or cooling system of the building is significant. The desire of making field measurements of this time-varying quantity has led to the development of many approaches. The simplest one is called the passive ventilation measurement technique which typically measures the average concentration of a constantly emitted tracer gas from which the average ventilation rate can be estimated. This study relied on mathematical models combined with typical wheather data to calculate how an ideal passive ventilation measurement would perform; simulations were then conducted based on two house types in four seasons and six climates. It was found that the passive technique significantly underpredicted the average ventilation and that the use of multiple tracers accomplished marginal improvement. Inadequate mixing was found to be a major impediment to the interpretation of the results and could completely invalidate the measurement. Not covered in this report are the additional errors associated with measurement uncertainty, instrumentation limitations and non-ideal experimental conditions.

Relating actual and effective ventilation in determining indoor air quality

Ventilation is both a mechanism for removing indoor air pollutants, and a potential energy load on the heating or cooling system of a building. Quantitative estimates of the ventilation rates, important for both of these applications, necessitate determining time-averaged quantities. The time-averaged ventilation rate appropriate for indoor air pollution, however, is different from that associated with energy load. We derive ventilation efficiencies for well-mixed, homogeneous, time-varying concentrations and corroborate findings with field data from a test house in Edmonton, Alberta, which indicate that monthly ventilation efficiency ranges from 79% to 92% with an annual average of 80%, and that hourly temporal ventilation efficiencies vary over a much larger range than time-averaged quantities.

Foliage plants for removing indoor air pollutants from energy-efficient homes

A sealed, Plexiglas chamber with temperature and humidity control and illuminated externally with wide spectrum grow lights was used to evaluate the ability of golden pothos (Scindapsus aureus), nephthytis (Syngonium podophyllum), and spider plant (Chlorophytum elatum var.vittatum) to effect the removal of formaldehyde from contaminated air at initial concentrations of 15–37 ppm. Under the conditions of this study, the spider plant proved most efficient by sorbing and/ or effecting the removal of up to 2.27 fig formaldehyde per cm2 leaf surface area in 6 h of exposure. The immediate application of this new botanical air-purification system should be in energy-efficient homes that have a high risk of this organic concentrating in the air, due to outgassing of urea-formaldehyde foam insulation, particleboard, fabrics and various other synthetic materials.