1381 / 2024-09-26 10:05:09

Contribution of primary emission to aminiums in atmospheric particulates collected in bait-feeding marine fish culture area

aminium,atmospheric particulate,primary emission,marine fish culture area

The amines released from the ocean have significant climate-regulating effects. However, their biological sources and release mechanisms are controversial. From May 2019 to December 2020, we collected atmospheric particulate samples from a feed-free (Type 1) and feed-adding aquaculture area (Type 2) along the northern coast of China, respectively. The results showed that in Type 2, the average sum of monomethylaminium (MMAH⁺), dimethylaminium (DMAH⁺), trimethylaminium (TMAH⁺), and diethylaminium (DEAH⁺) in PM_0.03-10 was 0.75±0.61 nmol m⁻³ (mean±standard deviation), which was 25 times higher than that of Type 1. Notably, in the bait-feeding fish farming, the highest sum concentration of the four aminiums was observed (1.41±0.63 nmol m⁻³), while the concentrations of DMAH⁺ and MMAH⁺ accounted for 96±5% of their sum concentration of the four aminiums. A large amount of amine precursors were detected in frozen feed-type marine fish, and it was inferred that the degradation of frozen feed-type fish was the primary source of the high concentration of atmospheric aminiums collected in Type 2. Furthermore, near the aeration tank of the indoor farming workshop, DMAH⁺ and MMAH⁺ were mainly distributed on particles with a dynamic diameter of 0.26 µm to 4.40 µm. They all showed a significant positive correlation with Na⁺ in different size particles, suggesting that these ions are mainly released into the atmosphere with sea spray. This study facilitated the accurate assessment of marine-sourced amines in the atmosphere.

海洋释放的胺具有显着的气候调节作用。然而，它们的生物来源和释放机制存在争议。从 2019 年 5 月到 2020 年 12 月，我们分别从中国北部沿海的无饲料（1 型）和添加饲料水产养殖区（2 型）收集了大气颗粒物样本。结果显示，在 2 型中，PM_0.03-10 中单甲胺 （^MMAH+）、二甲胺 （^DMAH+）、三甲胺 （^TMAH+） 和二乙胺 （^DEAH+） 的平均总和为 0.75±0.61 nmol m⁻³ （平均值±标准差），比 1 型高 25 倍。值得注意的是，在饵料养鱼中，观察到四种胺的总浓度最高（1.41±0.63 nmol m⁻³），而 ^DMAH+ 和 MMAH⁺ 的浓度占其总浓度的 96±5%。在冷冻饵料鱼中检测到大量的胺前体，由此推断，冷冻饵料鱼的降解是 2 型中收集的高浓度大气胺的主要来源。此外，在室内农业车间的曝气池附近，^DMAH+ 和 ^MMAH+ 主要分布在动态直径为 0.26 μm 至 4.40 μm 的颗粒上。它们都与不同粒径颗粒中的 Na⁺ 呈显著正相关，表明这些钵离子主要随海浪释放到大气中。这项研究有助于准确评估大气中来自海洋的胺。