| abstract |
The invention discloses a preparation method of a biochar-based slow-release fertilizer capable of passivating soil heavy metals, which comprises the following steps: (1) adding straw biomass powder into a magnesium chloride solution for mixing, soaking, filtering out and drying, and then Transfer to an anoxic atmosphere, pyrolyze at a temperature of 450-700°C to obtain magnesium-rich biochar materials; (2) use the magnesium-rich biochar materials in step (1) to mix, enrich and filter to obtain A biochar fertilizer rich in nitrogen and phosphorus; (3) using plant ash as an auxiliary agent, adding it to the biochar fertilizer in step (2), stirring and drying to obtain a biochar-based slow release that can passivate heavy metals in the soil Fat. The method of the present invention has strong versatility, simple process, less time-consuming, and can well realize "turning waste into treasure, treating waste with waste, and the slow-release fertilizer can not only passivate various heavy metals in soil and water bodies, but also can continue to grow crops. Provide effective nutrients. |