Removal of mixed malodorous gases emitted from sludge processing at a wastewater treatment plant using pilot-scale adsorbing columns with various impregnated activated carbons

• Published in: Journal of Japan Association on Odor Environment Vol. 38; no. 1; pp. 24 - 35
• Main Authors: FUKUYAMA, Joji, MASUDA, Junji
• Format: Journal Article
• Language: Japanese
• Published: Japan Association on Odor Environment 2007
• Subjects: Adsorption capacity; Deodorization; Impregnated activated carbon; Odor; Pilot-scale test
• ISSN: 1348-2904; 1349-7847
• DOI: 10.2171/jao.38.24

In order to make clear the characteristics of odorant adsorption by different types of activated carbon, three series of pilot-scale deodorization tests were conducted at a wastewater treatment plant. Activated carbons used were impregnated ones specified for acidic gases (e.g. hydrogen sulfide, methyl mercaptan, etc.), neutral gases (e.g. dimethyl sulfide, dimethyl disulfide, etc.) and basic gases (e.g. ammonia, etc.) and a non-impregnated one. Three PVC adsorption columns using a three-stage packed bed system were prepared for these tests. Each column was about 1.5m in height and 280mm in diameter. The design capacity of each column is 0.75m3/min. Odorous gas containing hydrogen sulfide at approximately 10ppm was continuously fed to three columns at a linear velocity of about 0.2m/s. The term of each test was about 100 days and odor measurement was usually carried out once a week. Data related to odor removal efficiency could be obtained for 9 different combinations of packed carbon types. From these results, total loading of odorants fed to the column till break-through was calculated for each impregnated activated carbon. Obtained value of adsorption capacity was lower than that of laboratory testing. It was thought that decrease of adsorption capacity in field testing was caused by many kinds of odorants contained in the inlet gas of the adsorption columns. Ammonia contained in the inlet gas heightened the value of H2S adsorption capacity for acidic gas-impregnated carbon ; however it caused corrosion due to reaction with impregnated chemicals for neutral gas-impregnated carbon. It was considered that the results of these pilot-tests would give us much useful information for the design planning and maintenance of odor adsorption facility.