MONITORING AND FORECASTING OF ODOR AFTER DEWATERING IN WASTEWATER TREATMENT
Ampun Janpengpen1, Gregory Baecher1, Ph.D., Hyunook Kim2, Ph.D.,Christopher Peot3, P.E., Mark Ramirez3
1Department of Civil and Environmental Engineering, University of Maryland, USA
2United States Department of Agriculture, USA
3District of Columbia Water and Sewer Authority,
(free)
A real-time odor monitoring system was developed to evaluate and predict odors levels of dewatered
solids generated by the District of Columbia Water and Sewer Authority’s (DCWASA) advanced 370 mgd
wastewater treatment plant (WWTP) in Washington, DC. Each year, DCWASA applies biosolids to over
20,000 acres of agricultural land. Nuisance odors from recycling biosolids on land may drift into
surrounding neighborhoods and result in neighboring communities enacting legislation to ban land
application, therefore, the reduction of odor emissions from biosolids recycled on field sites is a major
concern.
Odor levels generated by dewatered solids were measured as total volatile reduced sulfur compounds
with an online electro-chemical headspace monitoring device. The study correlates odor levels of
dewatered biosolids to various operational parameters throughout the wastewater treatment process and
forecasts total volatile reduced sulfur odor emissions of dewatered solids prior to recycling on agricultural fields.
The model indicates that the secondary blanket level at west odd is the most significant factor for odor
level of dewatered solids and that blanket level more than 1.8 ft will cause a significant increase in odors.
This model also found that polymer addition and therefore procurement costs increases during the
dewatering process as the odor and septicity of the dewatered solids increases.
KEYWORDS
Biosolids, odor, forecasting, dewatering process, total volatile reduced sulfur, blanket level, dewatered
solids, and statistical model.
