Evaluation of Inoculated Waste Biological Stabilization Degree by Olfactometric Methods

Abstract

As a result of compounds’ transformation in the waste biostabilization phases, there is an increase in odor nuisance and health problems among people exposed to odorants. Linking the odor concentration to the degree of waste biostabilization may be an important tool for the assessment of individual technological variants of biostabilization. The study aimed to link the odor emissions to the biostabilization degree in individual process variants that differed in the inoculum. The tests were carried out on inoculated windrows on the waste mechanical-bological treatment open site. Odor concentrations were measured during the entire seven-week process of biostabilization (weeks 1–7) and compared with kinetics parameters of organic compounds’ decomposition. The olfactometric tests showed the necessity of using the preparation to reduce the value of odor concentration. Research proved that the decrease of odor concentration values could be useful to indicate the particular phases of biostabilization. Also, the proposed method provides an opportunity to optimize the process concerning the function related to the low degree of odor nuisance of the technologies, including selection of environmentally safe inoculum. This issue has application values that may result in the implementation of new control systems for waste stabilization bioreactors and the evaluation of applied technological solutions.

Odors Emitted from Biological Waste and Wastewater Treatment Plants: A Mini-Review

“…For instance, the co-composting process of kitchen waste and garden waste are reported as a good strategy to decrease the emissions of ammonia and hydrogen sulfide, as well as enhancing compost maturity [44]. In fact, several studies point to a correlation between waste stability and odor [10,45], which is an interesting aspect to consider in the biological stages of an organic waste treatment. In fact, Gutiérrez et al (2017) presented a successful correlation between Oxygen Uptake Rate (OUR) and odor emissions (in this case, measured as odor units) when using different substrates, including the OFMSW and other substrates [46].…”

“…However, it is difficult to predict the odor threshold of a mixture of VOCs and other odorant compounds such as ammonia or hydrogen sulfide, since there are often complex and nonlinear synergistic effects that can alter both the strength and quality of the perceived odor. In such cases, the odor threshold of the emitted mixture must be determined by practical measurements, usually dynamic olfactometry, that is, with the involvement of odor panelists [10].…”