Department of Chemistry, University of Science and Technology of China, Hefei 230026, China.
Chemosphere. 2013 Nov;93(9):2069-75. doi: 10.1016/j.chemosphere.2013.07.041. Epub 2013 Aug 16.
Biochar, the byproduct from fast pyrolysis of waste biomass, is widely used as a soil conditioner. The phosphorus in biochar is not only a P source for plant growth, but also an important factor caused the eutrophication of water. Here, the effects of environmental conditions on the release of different P species from biochar in a biochar-water system were investigated. About 2.2 mg g(-1) P in the form of inorganic orthophosphate and pyrophosphate was released from a raw biochar (contained 4.7 mg P g(-1)) at initial pH of 9.0 in the initial 8h. The release of orthophosphate was significantly enhanced from 0.64 to 1.35 mg g(-1) by the coexisting anions of Cl(-), NO3(-) or SO4(2-) due to the effect of ion exchange competition, while the release of pyrophosphate (P2O7(4-)) was not influenced by the introduction of anions which might be attributed to the formation of stable complexes. The introduction of Hoagland nutrient solution led to the decrease in release of P due to the formation of precipitates between dissolved P and excessive Ca(2+) and Mg(2+).
生物炭是废物生物质快速热解的副产物，被广泛用作土壤改良剂。生物炭中的磷不仅是植物生长的磷源，也是导致水体富营养化的重要因素。本研究考察了环境条件对生物炭-水体系中不同磷形态从生物炭中释放的影响。在初始 pH 值为 9.0 的条件下，原生物炭（含 4.7mg P g(-1)) 在最初 8 小时内释放出约 2.2mg g(-1)以无机正磷酸盐和焦磷酸盐形式存在的磷。共存的阴离子（Cl(-)、NO3(-)或 SO4(2-)) 通过离子交换竞争显著促进了正磷酸盐的释放，从 0.64mg g(-1)增加到 1.35mg g(-1)，而焦磷酸盐（P2O7(4-))的释放不受阴离子引入的影响，这可能归因于形成了稳定的配合物。由于溶解的 P 与过量的 Ca(2+)和 Mg(2+)之间形成沉淀，引入 Hoagland 营养液导致磷的释放减少。
