FATE OF DISSOLVED ODOROUS COMPOUNDS IN SEWAGE-TREATMENT PLANTS

The concentration of selected malodorous compounds dissolved in water in different unit processes of actual treatment plant, and in differen t location of small scale treatment plants (Jokasos) were identified i n order to provide sufficient information to undertake proper action t o solve the problems of malodor compounds in water environment and in wastewater reuse. Analytic methods to measure as low as mg/l level of 16 odorous compounds were developed. In total, four sewerage treatment plants, three sludge treatment plants and six Jokasos were surveyed. Treatment plants were chosen in a way so that most types of unit proce sses could be covered. Being exposed to anaerobic condition is the pri mary reason of production of odorous compounds. As far as the secondar y treatment is operated properly, odorous compounds concentration in t he effluent can be maintained below odor threshold concentration. Odor ous compounds were produced during sludge treatment process while the sludge is sedimented, thickened and dewatered, or anaerobically digest ed; A new way to express the odor concentration is proposed to obtain quick and comprehensive visualization of odor intensity. (C) 1998 Publ ished by Elsevier Science Ltd. All rights reserved.