## 1 Introduction  
Agriculture-related emissions, including greenhouse gases (GHGs), ammonia (NH\({}_{3}\)), particulate matter precursors, and toxic pollutants, can travel across regions, adversely affecting air quality and posing significant risks to human health [1]. These far-reaching impacts highlight the urgent need for effective emission management strategies in agricultural systems to mitigate their environmental and health consequences [2]. In 2017, agricultural activities were estimated to be responsible for approximately 80% of NH\({}_{3}\) emissions from the Republic of Korea [3], in line with similar figures from the United States, China, and the European Union [4, 5, 6, 7]. Livestock manure is thought to be the single largest contributor to NH\({}_{3}\) emissions [8], estimated to account for around 50% of the total in the USA and China [9, 10]. Increased NH\({}_{3}\) emissions as a result of intensive agriculture are known to negatively affect environmental and ecosystem health through eutrophication [11] and as an indirect source of the potent greenhouse gas, nitrous oxide (N\({}_{2}\)O) [5, 12]. Per capita meat consumption in South Korea is projected to continue increasing over the next decade, with consumption of chicken and pork having doubled since the year 2000 and beef consumption increasing by more than 40% [13]. Available grazing and arable land is limited in South Korea [14], and pressure on agriculture production means that concentrated animal feeding operations (CAFOs) are common. Effectively managing the manure produced in these facilities is important for controlling NH\({}_{3}\) and odor pollution [10; 15]. Manure composting is an appealing management technique involving the growth of aerobic micro-organisms within the manure that break it down into a nutrient-rich organic fertilizer that can be applied to agricultural land [7]. When composted, biological degradation of the manure results in the production of sulfur dioxide (SO\({}_{2}\)) and nitric oxide (NO\({}_{\text{x}}\)) gases, as well as GHGs such as carbon dioxide (CO\({}_{2}\)), methane (CH\({}_{4}\)), and N\({}_{2}\)O [16; 17]. Ammonium (NH\({}_{4}\)\({}^{+}\)) is also created through microbial processes within the manure and although it is not volatile itself, it exists in equilibrium with NH\({}_{3}\) gas [12]. Factors that affect NH\({}_{3}\) emissions from manure compost include temperature, moisture content, pH, initial nitrogen content, and air turbulence [7; 12]. Aerating compost (via forced aeration, mechanical turning, and the use of organic bulking agents such as wood chips) has also been found to reduce direct emissions of the GHGs CH\({}_{4}\) and N\({}_{2}\)O, lowering the impact of manure composite on climate change, but this causes increases in the pH and temperature of the manure, shifting the equilibrium towards gaseous NH\({}_{3}\), increasing emissions, and leading to interest in capturing and scrubbing NH\({}_{3}\) from the air [18; 19; 20]. NH\({}_{3}\) emissions are thought to be an important contributor to the formation of secondary particulate matter. NH\({}_{3}\) gas reacts with acidic compounds (such as SO\({}_{2}\) and NO\({}_{\text{x}}\)) in the atmosphere, resulting in PM\({}_{2.5}\) formation [21; 22]. Studies have investigated the role of NH\({}_{3}\) interactions with SO\({}_{2}\) and NO\({}_{\text{x}}\) in contributing to severe PM\({}_{2.5}\) episodes in both South and East Asia [6; 23; 24], as well as in Europe [25; 26] and North America [9; 27]. Poor air quality is among the greatest issues currently facing East Asian societies, negatively affecting health outcomes [28; 29] and economic productivity [30] across the region. Better understanding NH\({}_{3}\) emissions from the manure composite process and their behavior as a constituent of the atmospheric aerosol load is a crucial element in creating better farm management systems, improving public health outcomes, and mitigating the broader environmental and climatic impacts of agriculture.