Abstract
This study intends to investigate the characteristics of the foul smell of sewer pipes near large apartment complexes as complaints about offensive odors have drastically increased in urban residential areas. Targeting apartments where people actually complained about foul orders, the study result revealed that components in the smell of the water-purifier tank of the target apartment were very similar to those of sewage treatment plants and night soil treatment plants. Measuring components of odors inside the management layer of tank showed that the concentration of hydrogen sulfide was 10ppm, which is approximately 160 times the safety standard of 0.06ppm; the concentration of mercaptan was 0.9ppm, which is about 220 times the safety standard of 0.004ppm. The source materials of foul odors were discharged outside through ducts, and those households living near outlets producing bad smell complain that it gets worse depending on the air pressure or wind direction and strength, and they could not even open windows. As well, these source materials were transferred by discharge pumps to public sewer pipes outside the apartment complex. While discharge pumps starts operating, they remain on the sewer pipe and then begin to spread over to roads through small openings of manholes on the road. Then, the smell offends passers-by and residents near the road, leading to a lot of complaints. The study results suggest that, among the sources of foul odors in sewer pipes of residential areas, especially those from the water-purifier tank of large apartments, hydrogen sulfide should be the main target for follow-up treatment.