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Most cadmium-polluted farmland and land surrounding mining areas are difficult to repair and control, seriously threatening the food safety of the crops planted in these regions. As an essential element for plant growth, calcium plays an important role in stress-resistance regulation. In this study, Brassia campestris L. was used as the experimental material and polluted soil with cadmium was used as the experimental soil sample, to explore the competition inhibition of calcium polypeptide application on the absorption of Cd2+ by Brassia campestris L. in the growth process, as well as the effect of calcium application on the growth. Results showed that the application of calcium polypeptides significantly promoted the growth of Brassia campestris L. Calcium polypeptides could be used as high-quality fertilizer, alleviating the effect of Cd2+ stress on the growth of Brassia campestris L., and promoting the absorption of K+, Ca2+, and other nutrients by Brassia campestris L. Under different calcium polypeptide application conditions, the effective state of Cd2+ in the soil showed less significant difference, indicating that the calcium polypeptide had weak or limited passivation effects on Cd2+. There was a significantly negative correlation between Cd concentration in Brassia campestris L. and calcium application (r = −0.99, p < 0.01) when calcium polypeptide was over-applied, which indicates that the inhibition effect of Cd2+ absorption on Brassia campestris L. is mainly through competitive inhibition rather than passivation. The results showed that calcium polypeptide has dual functions on the competitive inhibition of heavy metals and a good fertilizer effect, providing a new technology for in situ remediation of heavy-metal pollution, and a new approach for the treatment of cadmium-contaminated farmland and surrounding mining land.

The typhoon process has a significant influence on the distribution of heavy metals in sediments. Based on the heavy metal (V, Cr, Co, Ni, Cu, Zn, Pb, and Mn) contents in surface sediments collected under normal conditions and post-typhoon Matmo in Quanzhou Bay in 2014, the distributions, sources, and impacts of typhoon processes on heavy metals and pollution conditions were studied and discussed. The results showed that the heavy metals can be divided into two categories: Class I metals (Cu, Zn, Pb, and Mn) were mainly distributed in the estuary and significantly increased after the typhoon, and Class II metals (V, Cr, Co, and Ni) were distributed in the coastal intertidal zone and estuary and remained unchanged or decreased after the typhoon. The heavy metal assessment showed that heavy metal pollution in Quanzhou Bay was serious and tended to increase after the typhoon. The increased metal supply and enhanced riverine and tidal hydrodynamics after the typhoon may be the main factors influencing the variations in heavy metal content and distribution. This study provided a basis for the accurate evaluation and scientific management of heavy metal pollution caused by typhoon processes in Quanzhou Bay.

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