209. Effect of Inlet and Exhaust Locations and Density of Contaminant Gas on Indoor Air Contaminant Concentration

Several school buildings in Sweden have indoor air quality problems. The contaminant source is often assumed to come from within the construction, for example from the crawl space or attic space. Contaminants, in these cases, are transported by air leaking between compartments in the building. Here, the driving force for the air leakage is difference in pressure and, therefore, determining pressure also determines the direction of contaminant transport. In many cases, measures to improve the air quality are taken without a thorough understanding of how it might affect the pressure distribution in the building. In this paper a numerical model is used to examine how different climate scenarios and different building configurations affect the leakage and contaminant transport in a building with a crawl space. Results show that for leaky buildings the ventilation rate increases with increased wind and therefore the contaminant concentration decreases. The worst scenario in terms of high contaminant concentration is mild days with little wind. Also, when installing an exhaust fan in the crawl space with the purpose to prevent air from leaking from the crawl space to the classroom it is advisable to also consider the airtightness and the climate, not only the pressure difference across the floor.

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Novel porous single-crystalline ZnO nanosheets fabricated by annealing ZnS(en)0.5(en = ethylenediamine) precursor. Application in a gas sensor for indoor air contaminant detection

Nanotechnology ◽

10.1088/0957-4484/20/12/125501 ◽

2009 ◽

Vol 20 (12) ◽

pp. 125501 ◽

Cited By ~ 115

Author(s):

Jinyun Liu ◽

Zheng Guo ◽

Fanli Meng ◽

Tao Luo ◽

Minqiang Li ◽

...

Keyword(s):

Gas Sensor ◽

Indoor Air ◽

Single Crystalline ◽

Contaminant Detection ◽

Zno Nanosheets ◽

Air Contaminant

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Development of Palm Shell Base Activated Carbon for Volatile Organic Compounds (VOCs) Emissions Absorption

International Journal of Advanced Technology in Mechanical, Mechatronics and Materials ◽

10.37869/ijatec.v2i1.42 ◽

2021 ◽

Vol 2 (1) ◽

pp. 35-45

Author(s):

Abdul Mutalib bin Leman ◽

Muhammad Syafiq Muzarpar ◽

Mohd Norhafsam Maghpor ◽

Khairunnisa Rahman ◽

Nik Normunira Mat Hassan ◽

...

Keyword(s):

Activated Carbon ◽

Adsorption Capacity ◽

Indoor Air ◽

Holding Time ◽

Composition Analysis ◽

Activation Process ◽

Volatile Content ◽

Cleaning Product ◽

Palm Shell ◽

Air Contaminant

High concentration of indoor air contaminant commonly released by human activities, furniture, building materials, carpets, cleaning product and paints. BTEX contains Benzene, Toluene, Ethylbenzene and Xylene (BTEX) is categorized into VOCs which are indicative of harmful chemicals especially for indoor air. Therefore, it needs the sampling media for absorption before it could be analyse in the specific laboratory. One of the challenging technology to absorb BTEX is by using Palm Shell Activated Carbon (PSAC). Malaysia has a second largest country that produce palm oil which led to abundant of palm shell as waste material. Activated carbon is created through the carbonization, crushing and activation process. Carbonization process is conducted in various holding time of 1, 2 and 3 hours which called by CT1. CT2 and CT3 hours, respectively. Activation process is conducted through physical activation at temperature of 900 0C for 1 hour, chemical activation is conducted by Potassium Hydroxide (KOH) with ratio of 1:1 (charcoal: chemical) and holding time for 12 hours. It heated by furnace at temperature of 850 0C for 1 hours in order to improve the porosity and larger surface area. The physical properties were conducted by ASTM 3713, 3714 and 3715 for moisture, as and volatile content measurement. Surface morphology and composition as well as porosity image is characterized by Scanning Electron Microscopy (SEM) coupled by Energy Dispersive Spectroscopy (EDS) machine. The result shows that the lowest ash, moisture and volatile content is shown by CT1 sample, but it has not completely carbonized as compared to CT2 and CT3. Moreover, CT3 has highest ash, moisture and volatile content but it has lowest fixed carbon as compared to CT1 and CT2. Therefore, CT2 hours is selected for further process. In microstructure analysis is observed that the PSACphysical+chemical has larger number of porosities with the diameter approximately of 50 to 150 µm, for PSACphysical approximately of 25 to 100 µm and PSACchemical of below than 50 µm. Composition analysis is observed that the sample is mainly consists of Carbon (C), Oxygen (O) and Potassium (K) content. Where larger porosity is in-line with the increment of K content which indicated in larger adsorption capacity. It can be summarized that palm shell with 2 hours carbonization time and it activated become PSACphysical+chemical has a high potential to larger adsorption capacity of indoor air contaminant adsorption. It is being further explore for sampling media of BTEX.

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