Zhou Hongsong, Fan Jing, Shi Changrong, Li Kai, Huang Jizhen, Hu Jianquan, An Liangliang, Liu Yuxin
Faculty of Chemical Engineering, Kunming University of Science and Technology, Kunming, Yunnan, 650500, China.
Faculty of Chemical Engineering, Kunming University of Science and Technology, Kunming, Yunnan, 650500, China.
Environ Res. 2025 Oct 1;282:121987. doi: 10.1016/j.envres.2025.121987. Epub 2025 May 27.
Black liquor holds significant promise as a liquid fertilizer due to its liquid state and valuable soluble nutrients. However, its high alkalinity limits its direct use in agriculture. Reducing the alkalinity is necessary, but it also reduces the lignin solubility, affecting the permeability of black liquor to the soil and the availability of organic matter to plants. In this work, a desalination/oxidation coupling method was developed to transform black liquor into a liquid fertilizer, specifically focusing on reducing high alkalinity without sacrificing organic matter availability. The transformation of black liquor and its practice in soils were systematically evaluated. Desalination effectively reduced alkalinity, salinity, and electrical conductivity by removing inorganic salts, while in-situ oxidation enhanced the solubility and bioavailability of organic matter through lignin modification and the introduction of oxygenated functional groups. The desalinated-oxidized black liquor significantly enhanced the soil's humic acid levels, organic matter, and water retention while also improving its permeability. In planting experiments, plants irrigate with the treated black liquor demonstrated increased root length and higher survival rates compared to those irrigated with pure water or raw black liquor. Additionally, the chlorophyll content of these plants was significantly increased, up to 0.912 mg/g. This study presents an effective method for converting black liquor into an available liquid fertilizer, addressing environmental concerns and promoting the high-value agricultural reuse of industrial waste.
由于黑液呈液态且含有宝贵的可溶性养分，因此作为液体肥料具有巨大潜力。然而，其高碱度限制了它在农业中的直接使用。降低碱度是必要的，但这也会降低木质素的溶解度，影响黑液对土壤的渗透性以及植物对有机物的可利用性。在这项工作中，开发了一种脱盐/氧化耦合方法，将黑液转化为液体肥料，特别关注在不牺牲有机物可利用性的情况下降低高碱度。系统评估了黑液的转化及其在土壤中的实践。脱盐通过去除无机盐有效降低了碱度、盐度和电导率，而原位氧化通过木质素改性和引入含氧官能团提高了有机物的溶解度和生物利用度。脱盐氧化后的黑液显著提高了土壤的腐殖酸水平、有机质含量和保水性，同时还改善了其渗透性。在种植实验中，与用纯水或原黑液灌溉的植物相比，用处理后的黑液灌溉的植物根系长度增加，存活率更高。此外，这些植物的叶绿素含量显著增加，高达0.912毫克/克。本研究提出了一种将黑液转化为可用液体肥料的有效方法，解决了环境问题，促进了工业废物的高价值农业再利用。
