Activated Carbon and Wood Ash Sorption of Wastewater, Compost, and Biosolids Odorants

Odor emissions from wastewater treatment facilities and composting operations and land application of biosolids are priority concerns for wastewater engineers, compost operators, and biosolids managers. High carbon wood ash is a material produced by the pulp and paper industry and cogeneration energy producing facilities; although this material has been found to have characteristics similar to activated carbon, it is currently treated as waste and deposited in landfills. To control odors associated with wastewater and biosolids, activated carbon and wood ash were exposed to odorants that often are associated with biosolids and wastewater, including dimethyl disulfide, dimethyl sulfide, carbon disulfide, ammonia, trimethyl amine, acetone, and methyl ethyl ketone. The sorption materials included activated carbon containing 87% carbon and wood ash residuals containing 32, 27, 6, and 0.24% carbon, with surface areas of 520, 85, 74, 25, and 2.1 m2/g, respectively. This laboratory sorption experiment was undertaken to examine sorption efficiency and kinetics of chemical odorants by activated carbon and wood ash residuals. Results demonstrate that wood ash with higher carbon concentrations and higher surface areas sorbed odorants better than low‐carbon ash. Furthermore, the 32 and 27% carbon wood ash possessed characteristics similar to activated carbon and were able to sorb odorous gases effectively.