The removal of heavy metal ions from the aqueous environment is an important topic as heavy metal pollution is widely distributed in water bodies, causing serious damage to aquatic ecosystems and worsening the already scarce freshwater resources. In this work, we report the synthesis of novel ZIF-8@GO-COOH composite nanosorbent materials by in situ self-assembly. The physicochemical properties of the composites were investigated using relevant characterisation techniques, and the adsorption capacity of ZIF-8@GO-COOH for copper and lead ions in aqueous solution was tested by batch adsorption experiments. The adsorption behaviour was analysed by combining adsorption kinetics, adsorption isotherm model and Van't Hoff model. The results showed that the adsorption capacities of ZIF-8@GO-COOH for Cu(II) and Pb(II) were 93.26 mg/g and 95.875 mg/g, respectively, when the initial heavy metal ion concentration was 100 mg/L, the adsorption time was 60 min, the temperature was 293 K and the pH conditions were suitable. The high adsorption performance of ZIF-8@GO-COOH was attributed to its surface with abundant oxygen-containing functional groups and excellent specific surface area, which gives it a significant advantage in the removal of heavy metal ions from aqueous solutions.
Spent adsorbents often contain harmful substances, which may have an impact on the ecological environment if these substances enter the environment. This study mainly introduces a safe treatment method for solid waste formed after heavy metal ions are adsorbed by an efficient adsorbent, ZIF-8@GO-COOH. This work mainly discusses the impact of solidifying the spent adsorbent in the cement system on the cement mechanical properties and hydration process. The experimental results showed that when the dosage of the spent adsorbent was 0.01%, 0.02%, 0.03%, and 0.04%, respectively, the compressive strength of 28 d was increased by 4.24%, 6.16%, 7.19%, and 8.87%, respectively, compared with the cement without spent adsorbent. Introducing spent ZIF-8@GO-COOH in the cement production process does not have a negative impact on the cement mechanical properties, and can refine the cement pore structure and dense microstructure, thereby improving the compressive strength. The Toxicity Characteristic Leaching Procedure (TCLP) results showed that solidifying the spent adsorbent with cement can effectively reduce the leaching of heavy metal ions in the spent adsorbent. This study solidifies the spent ZIF-8@GO-COOH nanoadsorbent material into the cement system as a sustainable alternative to landfilling. This treatment method has certain economic benefits and safety, and has some reference significance for promoting the development and improvement of spent adsorbents and improving their safe treatment and reuse.
危险品化学品经营许可证（带存储）