Researchers studied phosphorus in sediments from Lake Hongfeng, China, using chemical fractionation and X-ray diffraction. They found high levels of phosphorus in the sediments, mainly in the form of calcium-bound phosphorus. This type of phosphorus is stable and not easily taken up by organisms. The sediments also contained aluminum-bound phosphorus, which is important for phosphorus release. The study showed that different phosphorus species were present in the lake sediments, with aluminum phosphate being a common one. The results suggest that phosphorus in the sediments could affect the lake's water quality, and further research is needed to understand how phosphorus moves in the environment.