碱活化载镁橘皮生物炭除磷后对土壤的改良作用

改性生物炭作为一种新型环保材料常被用于污水吸附除磷,然而吸附除磷后的改性生物炭若不妥善处理可能会对环境造成二次污染。为促进吸附除磷后生物炭的资源化、无害化利用,本研究将吸附除磷后的载镁橘皮生物炭(KMg-BC/P)用于土壤改良及大豆栽培。结果表明:添加适量的KMg-BC/P能显著提高土壤的pH、有机质含量、阳离子交换量、有效磷含量、总磷含量、磷素的释放量以及持水能力;同时增加土壤中高效磷源和缓效磷源的含量,提高土壤碱性磷酸酶活性,促进无机磷和低活性有机磷向高活性有机磷转化;此外其还能促进土壤中细菌的生长繁殖,同时降低真菌的数量和多样性。用KMg-BC/P改良后的土壤种植大豆能促进大豆的生长,使大豆的发芽率、植株高度、根长、叶片数量、大豆植株鲜质量和茎粗均优于对照组。因此,KMg-BC/P具有作为土壤改良剂的潜力。

Effects of alkali-activated magnesium-loaded orange peel biochar on soil improvement after phosphorus absorption

Modified biochar, which is a type of environment-friendly material, is often used in sewage adsorption to remove phosphate. However, if the biochar modified after phosphate adsorption is not treated properly, it can cause secondary pollution to the environment. In this study, to increase the number of resources for and to promote the harmless utilization of post-adsorption biochar, post-adsorption magnesium-carrying orange peel biochar(KMg-BC/P)was used to study improvements in soil conditions and to cultivate soybean. The results showed that the addition of KMg-BC/P in the appropriate quantity could significantly improve soil pH, organic matter content, cation exchange capacity, available phosphorus content, total phosphorus content, phosphorus release, and water holding capacity. Meanwhile, the contents of the high-efficiency phosphorus source and slow-acting phosphorus source increased, and the alkaline phosphatase activity in the soil also improved. KMg-BC/P also contributed to the conversion of inorganic phosphorus and low-activity organic phosphorus to high-activity organic phosphorus. In addition, KMg-BC/P promoted the growth and reproduction of soil bacteria and reduced the number and diversity of fungi. Cultivation in soil enriched with KMg-BC/P could promote soybean growth. This was indicated by the fact that the germination rate, plant height, root length, number of leaves, plant fresh weight, and stem thickness of soybean in the treatment group were better than the corresponding parameters in the control group. Therefore, KMg-BC/P may serve as a potential soil amendment.