The Effects Of Heavy Metals On The Safety Performance Of Artemia Shell Loaded Magnesium And Phosphorus Composite As A Slow-Release Fertilizer

The bio-composite material（Shell-Mg-P）could be used as a slow-release fertilizer to be applied to soils to improve soil quality and productivity.The reliability assessment of a slow-release phosphorus fertilizer resulting from heavy metal pollution is the important premise to the application of slow-release fertilizer,since the carrier of the slow-release fertilizer,Artemia shell is rich in chitin,which has an affinity for heavy metals.First,the adsorption effect of the biomaterial Artemia shell and bio-composite material loaded magnesium（Shell-Mg）on Pb²⁺,Cd²⁺,Zn²⁺and Cu²⁺was tested.The test results show that Shell and Shell-Mg can absorb heavy metal,and Shell-Mg has higher affinity adsorption than Shell.Therefore,the significance of this research topic is established.In order to comprehensively evaluate the potential risks of coexistence metal ionsin the formation and application of slow-release fertilizer,the present study focus on the heavy metal adsorption of shell-Mg for phosphate removal from water also polluted with coexistence metal ions.Shell-Mg-P is suitable for application in neutral or nearly neutral soil,and in the partial acid,neutral or alkaline,slow-release effect is not obvious difference in the soil,Therefore,this experiment studied the sustained release performance of Shell-Mg-P-metal in deionized water;the effects of Shell-Mg-P and Shell-Mg-P-metal on wheat seedling in neutral soil;the effects of Shell-Mg-P and KH₂PO₄（non-slow-release fertilizer）on wheat seedlings in neutral soils contaminated by Pb（II）,Cd（II）,Zn（II）and Cu（II）.The results show that the heavy metal ions and phosphate can be absorb coinstantaneous from water;Besides,the Shell-Mg-P and Shell-Mg-P-metal can reduce the total concentration of heavy metals in wheat seeding in neutral or near neutral soil,when the pollution of heavy metal is not serious,and can promote wheat seeding growth;as well as shell-Mg-P is likely to promote the metals migration to the stem leaf for root,and may increase risk for food.Therefore,the security risks of heavy metals in slow-release fertilizer should be based evaluated basing on the metals and metal concentration it should not be only focused on total concentration of heavy metals in seedlings resulting from the slow-release fertilizer,but also should pay attention to the metals distribution in stems,leaves,and roots to ensure safe and reliable application of slow release fertilizer.