title: Chemical reduction of odour in fresh sewage sludge in the presence of ferric hydroxide.
abstract: To assess the potential of ferric hydroxide (FH) to reduce odour emission from dewatered sewage sludge with a moisture of approximately 86%, odour reduction was evaluated using an electronic nose and measurements of odorous compounds (hydrogen sulphide, ammonia and volatile fatty acids (VFAs)). The sulphur species including sulphate, acid-volatile sulphide (AVS), Cr(II)-reducible sulphide (CRS) and elemental sulphur (ES), were analysed by a modified cold diffusion sequential extraction method before and after anaerobic incubation. Within 32 days, 69.3, 83.8 and 88.6% of the odour (or 81.3, 93.7 and 97.5% of hydrogen sulphide) were eliminated, respectively, at the rates of 0.05, 0.10 and 0.25% (wt) of FH. The sulphur species analysis indicated that FeS, FeS2 and a small portion of S0 were formed by FH-sulphide reaction. This study also found that the relationship between odour and H2S concentrations could be well expressed by Steven's law. We believe that FH can be a cost-effective reagent for sludge odour control in sewage treatment processes.
authors.affiliation: School of Environmental Science and Engineering, The State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai, China.
authors.forename: Lianghu
authors.initials: L
authors.lastname: Su
authors.forename: Youcai
authors.initials: Y
authors.lastname: Zhao
mesh_terms: D000641:Ammonia / Q000032:analysis; D005232:Fatty Acids, Volatile / Q000032:analysis; D005290:Ferric Compounds / Q000737:chemistry*; D006862:Hydrogen Sulfide / Q000032:analysis / Q000737:chemistry; D009812:Odorants / Q000517:prevention & control*; D010758:Phosphorus / Q000032:analysis; D012722:Sewage / Q000737:chemistry*
chemical_list: D005232:Fatty Acids, Volatile; D005290:Ferric Compounds; D012722:Sewage; D010758:Phosphorus; C021024:ferric hydroxide; D000641:Ammonia; D006862:Hydrogen Sulfide