Dissolution ability of nano-zno and the influence of co-existing Cd2+
As one of the most widely used metal-based nanoparticles,nano-ZnO is toxic to organisms.One of the toxic mechanisms can be described as the dissolved zinc ions from nanoparticles.The coexistence of heavy metals may change the solubility of nano-ZnO,whereas nano-ZnO may remove Cd2+via adsorption,but the interactions between them remain unclear.Batch experiments were conducted to study the dissolution ability of nano-ZnO at different doses(200,400,1000,and 2000 mg/L)under different shaking times(12,24,and 36 h),as well as the influence of co-existing Cd2+.The results showed that in deionized water 1000 mg/L nano-ZnO led to the highest dissolution of Zn(3.71 mg/L),but the dissolution of nano-ZnO was not affected by the shaking time.The addition of 1 mg/mL Cd2+significantly enhanced the dissolution of nano-ZnO.When the dosage of nano-ZnO was 200 mg/L,the dissolution amount and dissolution percentage of Zn2+reached as high as 95 mg/L and 55%respectively.Increasing the dosage of nano-ZnO reduced the content and dissolution percentage of Zn2+,but increasing the shaking time did not enhance the dissolution of nano-ZnO.Nano-ZnO reduced Cd2+concentrations,indicating that nano-ZnO could adsorb Cd2+.In conclusion,co-existing Cd2+could change the environmental behavior of nano-ZnO,thus potentially altering its toxicity to organisms.
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维普
