A diverse range of volatile organic compounds (VOCs) are emitted from wastewater biosolids processing. Odorous emissions are predominately made up of volatile sulfur compounds (VSCs) which are typically the only odorants measured. However, a range of VOCs are known to contribute to malodours yet previous studies often overlook the contribution of VOCs in comparison with VSCs.
Odor emissions from biosolids limit opportunities for their beneficial reuse by land application. Odorous emissions are affected by the operation of stabilization processes via methods such as anaerobic digestion, aerobic digestion, alkaline treatment, thermal drying, or composting.
The composition of wastewater in sewer catchments is known to affect the performance of wastewater treatment plants (WWTPs). However, there is limited knowledge as to how catchment characteristics, such as types of catchment industries, impact odour emissions from downstream sludge processing and biosolids management.
This review provides a critical assessment of the production process routes of a wide range of value-added products from WAS, their current limitations, and recommendations for future research to help promote more sustainable management of this under-utilised and ever-growing waste stream.
Wastewater treatment plays a pivotal role in the protection of public and environmental health in urban precincts and in the recovery of scarce water and energy resources for an increasingly urban and growing global population. Yet wastewater treatment operations are among the most energy-intensive within urban precincts and so there is considerable scope to optimise wastewater treatment plants to improve their energy efficiency and reduce associated carbon emissions.
Opportunities for the beneficial re-use of biosolids are limited by nuisance odour emissions. Volatile organic compounds (VOCs) from anaerobically stabilised biosolids were measured to identify compounds that could contribute to the overall odour character of nuisance emissions. Flux hood sampling and chemical analysis were used to identify VOCs emitted from biosolids as they were stored in ambient conditions. Compounds emitted varied as the biosolid cakes were stored for a period of 50 days.