Development of adsorbent/catalyst from municipal wastewater sludge

Abstract

The objective of this research work is to investigate the possibility of using sewage sludge as a source to produce adsorbent for odorous gas removal. The basic method of adsorbent preparation is pyrolysis in nitrogen gas. The effects of heating temperature and resident time are investigated. Treatments such as drying in air at low temperature and soaking in chemicals prior to pyrolysis are attempted. The prepared adsorbents are characterized by an automatic surface area porosimeter in terms of BET surface area, pore size distribution. The highest BET surface area achieved is 309 m2/g, where the sludge is soaked in 5M zinc chloride solution and dried at low temperature before heating to 650°C for two hours. Laboratory tests at 17.5 ppm H2S concentration show that the sludge-derived adsorbent has an H2S adsorption capacity 25% that of a commercial activated carbon (Calgon IVP 4×6) over 15 hours of duration.