Characterization of Odors from Limed Biosolids Treated with Nitrate and Anthraquinone

Abstract

Complaints from the public due to odor emissions are one of the biggest problems associated with any biosolids land application program. Chemical additives to reduce or mask odors are one option for producers; however, many chemicals are too expensive or are too unstable to use safely. This project provides a preliminary evaluation of nitrate or nitrate + anthraquinone as additives in controlling odors from limed biosolids. Over a twenty-four day period, odors were measured in the headspace over several treatment levels using two different chemical analysis tools along with olfactometric evaluation of odor intensity and hedonic tone. On six days during the sample period, hydrogen sulfide was measured using a Jerome 631X, a sensor that also responds to other reduce sulfur gases. Other specific sulfides, amines, and mercaptans were also determined using solid phase microextraction with gas chromatography-mass spectrometry. A simple sniff test approach was used with six panelists on five days during the project. The chemical analysis results revealed that the addition of nitrate and especially nitrate + anthraquinone was effective in reducing concentrations of hydrogen sulfide and methylmercaptan when compared to untreated limed biosolids. However, the olfactometric results did not reveal any significant differences between treatments. The panelists also found that all treatments exhibited a fishy or ammonical character, indicative of amines, or ammonia. More advance olfactometric analysis utilizing dilution techniques might have been able to distinguish between treatments, but it is likely that amines were the dominant odorant released from all treatments. This preliminary project suggests that chemical addition of nitrate or nitrate + anthraquinone would be most effective in controlling odors from unlimed biosolids such as anaerobically digested materials.

Effects of intermittent chemical dosing on volatile sulfur compounds in sewer headspace

“…Besides, different chemicals including ferric chloride and hydrogen peroxide showed that all could reduce VOSCs production in biosolids and freshwater sediment, and none were vastly superior to the other [22]. However, the result in this study showed that the concentration of VOSCs rebounded in the late-stage experiment which was inconsistent with the previous study.…”

Explaining Sources of Biosolids Odors at Wastewater Treatment Plant (WWTP) by Utilizing Real-Time Odor Monitoring System and Statistical Models

“…Many studies indicated that TRS, which includes dimethyl sulfide (DMS), dimethyl disulfide (DMDS), carbon disulfide (CS 2 ), and methyl mercaptan (MM) and N-containing compounds including ammonia (NH 3 ) and trimethylamines (TMA) are the major odorous compounds emitted from lime stabilized biosolids Kim et al 2001;Murthy et al 2002b;Novak et al 2002;Kim et al 2002;Kim et al 2005;Schneekloth et al 2006;Chang et al 2005;Chen et al 2005). However, many studies showed that lime stabilization can diminish or eliminate hydrogen sulfide (H 2 S) (USEPA 1985;Stuetz and Frechen 2001;Murthy et al 2001;Kim et al 2001), but there are other odorants concentrations that can be detected in limed biosolids.…”

Odour reduction strategies for biosolids produced from a Western Australian wastewater treatment plant: results from Phase I laboratory trials

“…Solid-phase microextraction (SPME) coupled with GC-MS has also been used for the analysis of odorous compounds in several biosolids projects (e.g. Turkmen, et al, 2004;Kim et al, 2005). However, many of these methods used complicated apparatus for the calibration and sampling of the gaseous odorants and involved manual injections of the SPME fibre into the GC injector.…”