Treatment of unpleasant odors in municipal wastewater treatment plants

Abstract

The purpose of this paper to present a case study on how to address the odor problem from secondary sources within a municipal wastewater treatment plant (WWTP) by first identifying the locations of the problem and second by evaluating alternative treatment technologies. The WWTP of Chania is a typical 100,000 equivalent inhabitants-facility in a warm semi-arid environment which is located close to residential areas. The installation of a chemical scrubber to control major odor sources within the plant did not succeed in eliminating complaints by nearby residents, and additional measures were required. In this case study we identify all major secondary sources of odor within the plant and evaluate the effectiveness of the different technologies that were employed to address this problem (cover installation, gas and liquid phase oxidation, activated carbon/permanganate absorption, FeCl(3) addition). In particular, we found that installation of covers and reduction of turbulence at two key locations within the WWTP was the best strategy to combat unpleasant odors. Furthermore, when the central chemical scrubber was near capacity the installation of an auxiliary system of activated carbon absorption coupled to permanganate oxidation was deemed to be a safe approach. However, despite the very high removal efficiency (>99.5%) of the unit, the addition of FeCl(3) in the liquid phase was required in order to achieve complete deodorization (below the human odor threshold level).

Current Status and Outlook of Odor Removal Technologies in Wastewater Treatment Plant

“…are biological approaches for odor control. Physical/chemical technologies have been broadly implemented since their rapid start-up, low empty bed residence time (EBRT) and extensive experience in design and operation [20][21][22][23][24]. These techniques are often based on the transfer of odorants from the gas emission to either a solid (adsorption) or liquid (absorption) phase.…”

Assessment of the Effects of Wastewater Treatment Plant Modernization by Means of the Field Olfactometry Method

“…Next to the basic, typical sources of odors at the WWTP, locations with high odor potential within the WWTP include, inter alia, screening facilities and flow equalization basins, and secondary clarifiers constitute low/moderate potential odor sources. Moreover, the locations of anaerobic digestion, sludge storage basins, and mechanical dewatering exhibit moderate/high odor potential [53]. In the present study, the secondary settling tank has low, while the screening processing line has high odor potential (especially its last stage, where screens were stored in an open space area).…”

Limitations of GC-QTOF-MS Technique in Identification of Odorous Compounds from Wastewater: The Application of GC-IMS as Supplement for Odor Profiling

“…Compared with the industrial odor, the odor of domestic wastewater during treatment in WWTPs is complex and variable, due to its wide sources and various biochemical reactions. As known, odorous emissions from WWTPs are made up of inorganic compound (hydrogen sulfide, ammonia) and organic compound (sulfur organic compounds, nitrogenous organic compounds, alcohols, aldehydes, terpenes, carbonyls, aromatics, fatty acids, alkanes, alkenes, ketones, esters and halogenated hydrocarbons) [4][5][6][7][8][9][10][11][12]. Among them, volatile sulfur organic compounds (VSOCs) are principal odorants except hydrogen sulfide, and non-sulfur volatile organic compounds (VOCs) are increasingly important to contribute to odorous emission [13].…”