Comparison of seasonal phenol and p-cresol emissions from ground-level area sources in a dairy operation in central Texas

Effect of farm Hazard Analysis and Critical Control Point (farm HACCP) certification efforts on emissions of volatile organic compounds from livestock sheds in Japan

"Farm HACCP" incorporates the concept of Hazard Analysis and Critical Control Points (HACCP) into farm animal husbandry and sanitation management to ensure the safety of livestock products and improve productivity. Implementing farm HACCP may reduce the emission of volatile organic compounds (VOCs), which are derived from livestock manure and are responsible for odors, PM2.5 , and photochemical oxidants. In this study, the effects of implementing farm HACCP on the emissions, composition, and environmental impact of VOCs from sheds were evaluated. VOCs in swine, dairy cattle, and hen sheds were measured before and after implementing farm HACCP. After implementing farm HACCP, the concentrations in the sheds were 55%-80% lower than the concentration in the sheds before. Odor activity values decreased in the cattle and hen sheds, whereas they increased in the swine shed. In addition, OH radical reactivity, an indicator of reactivity with OH radicals, decreased in all sheds. Finally, the emission rates of VOCs from each shed were estimated to be 42%-97% lower. These results suggest that implementing farm HACCP can reduce emissions of VOCs from livestock industries.

Determination of trace concentrations of simple phenols in ambient PM samples

Phenols are hazardous, but yet ubiquitous in the environment, including in atmospheric aerosols due to combustion emissions. There, phenols are subjected to secondary transformations, producing even more toxic nitrophenolic air pollutants. However, primary simple phenols, i.e. those containing only hydroxyl, methyl and methoxy substituents are not easy to detect. Trace concentrations, semi-volatile character and poorly ionizable functional groups prevent us from their determination by the most common analytical techniques, such as gas and liquid chromatography with mass spectrometric detection (GC/LC-MS). Here, we present a new derivatization method for MS/MS detection with positive ion electrospray ionization (+ESI-MS/MS) of simple phenols in atmospheric particulate matter (PM) extracts. The method is sensitive, selective, and robust, and requires no sample concentration step, which is critical due to the volatile character of the target analytes. After derivatization with dansyl chloride, phenol, catechol, cresols and guaiacol were detected in urban PM samples from Ljubljana, Slovenia. This method finally enables to study the abundance of primary phenols in atmospheric PM from different sources, which will improve understanding of secondary aerosol (trans)formation pathways and allow for more targeted mitigation strategies in respect to airborne phenolic pollutants.

Modelling aerosol molecular markers in a 3D air quality model: Focus on anthropogenic organic markers

We developed and implemented in the 3D air quality model CHIMERE the formation of several key anthropogenic aerosol markers including one primary anthropogenic marker (levoglucosan) and 4 secondary anthropogenic markers (nitrophenols, nitroguaiacols, methylnitrocatechols and phthalic acid). Modelled concentrations have been compared to measurements performed at 12 locations in France for levoglucosan in winter 2014-15, and at a sub-urban station in the Paris region over the whole year 2015 for secondary molecular markers. While a good estimation of levoglucosan concentrations by the model has been obtained for a few sites, a strong underestimation was simulated for most of the stations especially for western locations due to a probable underestimation of residential wood burning emissions. The simulated ratio between wood burning organic matter and particulate phase levoglucosan is constant only at high OM values (>10 μg m^-3) indicating that using marker contribution ratio may be valid only under certain conditions. Concentrations of secondary markers were well reproduced by the model for nitrophenols and nitroguaiacols but were underestimated for methylnitrocatechols and phthalic acid highlighting missing formation pathways and/or precursor emissions. By comparing modelled to measured Gas/Particle Partitioning (GPP) of markers, the simulated partitioning of Semi-Volatile Organic Compounds (SVOCs) was evaluated. Except for nitroguaiacols and nitrophenols when ideality was assumed, the GPP for all the markers was underestimated and mainly driven by the hydrophilic partitioning. SVOCs GPP, and more generally of all SVOC contributing to the formation of SOA, could therefore be significantly underestimated by air quality models, especially when only the partitioning on the organic phase is considered. Our results show that marker modelling can give insights on some processes (such as precursor emissions or missing mechanisms) involved in SOA formation and could prove especially useful to evaluate the GPP in 3D air quality models.

Forming 4-Methylcatechol as the Dominant Bioavailable Metabolite of Intraruminal Rutin Inhibits p-Cresol Production in Dairy Cows

Rutin, a natural flavonol glycoside, elicits its diverse health-promoting effects from the bioactivities of quercetin, its aglycone. While widely distributed in the vegetables and fruits of human diet, rutin is either absent or inadequate in common animal feed ingredients. Rutin has been supplemented to dairy cows for performance enhancement, but its metabolic fate in vivo has not been determined. In this study, plasma, urine, and rumen fluid samples were collected before and after the intraruminal dosing of 100 mg/kg rutin to 4 Holsteins, and then characterized by both targeted and untargeted liquid chromatography-mass spectrometry (LC-MS)-based metabolomic analysis. In plasma and urine, 4-methylcatechol sulfate was identified as the most abundant metabolite of rutin, instead of quercetin and its flavonol metabolites, and its concentration was inversely correlated with the concentration of p-cresol sulfate. In rumen fluid, the formation of 3,4-dihydroxyphenylacetic acid (DHPAA) and 4-methylcatechol after rapid degradation of rutin and quercetin concurred with the decrease of p-cresol and the increase of its precursor, 4-hydroxyphenylacetic acid. Overall, the formation of 4-methylcatechol, a bioactive microbial metabolite, as the dominant bioavailable metabolite of rutin and quercetin, could contribute to their beneficial bioactivities in dairy cows, while the decrease of p-cresol, a microbial metabolite with negative biological and sensory properties, from the competitive inhibition between microbial metabolism of rutin and tyrosine, has the potential to reduce environmental impact of dairy operations and improve the health of dairy cattle.

Effect of slurry treatment approaches on the reduction of major odorant emissions at a hog barn facility in South Korea

The characteristics of malodor released from piggery excreta samples were investigated by measuring their emission concentrations both before and after such treatments as composting or aeration from field sites. These samples were then collected from field sites and brought into the lab for analysis with the aid of the dynamic flux chamber method. The dominating compounds in the emissions were reduced sulfur compounds, phenol, and indole. The results were examined in terms of two key odor indices: odor intensity (OI) and odor activity values (OAVs), after being grouped by some criteria. When the odor contribution in the composting facility was assessed by the OAV value, methanethiol (53.1%), trimethylamine (TMA) (25.5%), and skatole (10.1%) were dominant in the pretreatment facilities, while skatole (64.7%) and p-cresol (27.9%) in the post-treatment specimens. Likewise, in the liquid treatment facility, hydrogen sulfide (47.4%), p-cresol (26.9%), and skatole (20.2%) were dominant in the pretreatment, while only p-cresol (73.6%) in the post-treatment. In comparison to the composting facility, the liquid treatment facility proved to be more efficient in the treatment of diverse hog-barn-related odorants.