UK Centre for Ecology and Hydrology, Bush Estate, Midlothian, United Kingdom.
School of Chemistry, The University of Edinburgh, Edinburgh, United Kingdom.
PLoS One. 2024 Jan 31;19(1):e0296679. doi: 10.1371/journal.pone.0296679. eCollection 2024.
Rising global energy prices have led to increased costs of nitrogen (N) fertilisers for farmers, but N pollution (losses) from agricultural activities can account for over 50% of the nitrogen applied. This study assesses the feasibility of a low-cost and low-tech method of NH3 emission capture from an agricultural point source (chicken manure) using a water column bubbling technique, and its application as a fertiliser to several plant types. Solutions of i) nitric acid (HNO3), ii) calcium nitrate (Ca(NO3)2), iii) a mixture of Ca(NO3)2 and HNO3 and iv) deionised H2O were used to scrub NH3 from air pumped from a storage container containing chicken manure. We conclude that NH3 can be captured from manure using low-tech methods, and that solutions of common fertiliser compounds such as ammonium nitrate and calcium ammonium nitrate can be replicated by binding captured NH3 to solutions of nitrate. Our results suggest that dissolved calcium nitrate is just as effective at scrubbing NH3 from the atmosphere as nitric acid at low concentrations, but could do so at a near neutral pH. For use on common silage grass for livestock feed, all of the captured ammonium solutions significantly increased yields, including the ammonium only solution. However, the aquatic plants (Taxiphyllum Barbieri and Salvinia auriculata) did not respond favourably to a high ratio of NH4+ in solution, and in the case of Salvinia auriculata, the plant was significantly damaged by the ammonium only solution. In conclusion, we highlight that the capture and utilisation of NH3 emissions from point sources is possible using very basic apparatus and that if used correctly, this captured nitrogen can be stored and applied to crops in a variety of forms which could reduce reliance and cost of mineral fertiliser use.
全球能源价格上涨导致农民购买氮肥的成本增加，但农业活动导致的氮污染（损失）可占施氮量的 50%以上。本研究评估了一种从农业点源（鸡粪）中捕获氨（NH3）的低成本、低技术方法的可行性，该方法利用水柱冒泡技术，将其作为肥料应用于几种植物类型。我们使用了以下溶液来从鸡粪储存容器中抽取的空气中去除 NH3：i）硝酸（HNO3），ii）硝酸钙（Ca(NO3)2），iii）Ca(NO3)2 和 HNO3 的混合物，以及 iv）去离子水。我们得出的结论是，可以使用低技术方法从粪便中捕获 NH3，并且可以通过将捕获的 NH3与硝酸盐溶液结合，来复制常见肥料化合物（如硝酸铵和硝酸钙铵）的溶液。我们的结果表明，在低浓度下，溶解的硝酸钙在从大气中去除 NH3 方面与硝酸一样有效，但可以在接近中性的 pH 值下进行。对于用作牲畜饲料的普通青贮草，所有捕获的铵溶液都显著增加了产量，包括仅含铵的溶液。然而，水生植物（水鳖和满江红）对溶液中高比例的 NH4+反应不佳，在满江红的情况下，植物仅因铵溶液而受到严重损害。总之，我们强调指出，使用非常基本的设备可以从点源捕获和利用 NH3 排放，如果使用正确，这种捕获的氮可以以各种形式储存并应用于作物，从而减少对矿物肥料的依赖和成本。
