[Effect of Ca Modified Biochar on the Chemical Speciation of Soil Phosphorus and Its Stabilization Mechanism].

To control of phosphorus release from soil after farmland inundation around the lake and reservoir， calcium modified biochar （Ca-BC） was prepared using the coprecipitation method. Through X-ray photoelectron spectroscopy （XPS）， X-ray polycrystalline powder diffraction （XRD）， adsorption experiments， and simulated culture experiments， the effects of Ca-based biochar on the fraction of soil phosphorus （P） and its stabilization mechanism were studied. The results showed that the adsorption process of Ca-based modified biochar conformed to Langmuir （ = 0.

[Speciation Distribution and Risk Assessment of Heavy Metals in Sediments from the Yitong River City Area].

The total content and chemical speciation of Cd, Cr, Cu, Ni, Pb, and Zn in seven short cores sampled from the Yitong River from Changchun City were analyzed to assess the pollution levels and potential ecological risks of heavy metals in the sediments. The results demonstrated that the total contents of Cd, Cr, Cu, Ni, Pb, and Zn in sediments were 0.10-1.