Estimation of the Odour Emission Capacity of High-load Wastewater

The Odour Emission Capacity (OEC) is an experimental parameter that quantifies the odour potential of a liquid, in terms of ouE/m3 liquid , based on the stripping of odorants contained in a known amount volume of liquid. The method was implemented for the first time in 1998 by Frechen and Köster and standardized in 2015 in the German technical standard VDI Guideline 3885/1. In particular, the sampling steps of gas phase for the dynamic olfatctometry analysis were fixed at 2, 6, 16 and 32 minutes. This work aims to propose a modified methodology to evaluate this parameter in wastewater which come from the sewer systems and industrial wastewater treatment plants (WWTP) characterized by high odour load (e.g. oil-refinery desalter water, oil-well water). The implementation of a system of dilution for the sampled gas, has appeared to be an important aspect to take into account in case of high odorous load, because it allows to perform the analysis also with smaller liquid volume (i.e. 1 L), a necessary condition for lab logistics and safety considerations as the safeguard of the involved operator’s health (e.g. panel members, lab analysts). In order to improve the accuracy of the result and optimize the methodology, a different approach was studied through the increase in the number of odour concentration measurements and the modification of the sampling times. Results show that increasing the time of analysis from 32 min to 2 days, the trend of the time-varying integral of OEC reaches a quasi-stationarity respect the same curve associated to the OEC estimated with the standard methodology.