Study of cyanide removal from contaminated water using zinc peroxide nanomaterial

The present study highlights the potential application of zinc peroxide （ZnO2） nanomaterial as an efficient material for the decontamination of cyanide from contaminated water. A process patent for ZnO2 synthesis has been granted in United States of America （US Patent number 8,715,612; May 2014）, South Africa, Bangladesh, and India. The ZnO2 nanomaterial was capped with polyvinylpyrrolidone （PVP） to control the particle size. The PVP capped ZnO2 nanomaterial （PVP-ZnO2） before and after adsorption of cyanide was characterized by scanning electron microscope, transmission electron microscope, X-ray diffractorneter, Fourier transform infrared spectroscopy and time of flight-secondary ion mass spectrom- etry. The remaining concentration of cyanide after adsorption by PVP-ZnO2 was determined using ion chromatograph. The adsorption of cyanide over PVP-ZnO2 was also studied as a function of pH, adsorbent dose, time and concentration of cyanide. The maximum removal of cyanide was observed in pH range 5.8-7.8 within 15 rain. The adsorption data was fitted to Langmuir and Fruendlich isotherm and it has been observed that data follows both the isotherms and also follows second order kinetics.

铜、锌氰配合物在离子交换纤维上的扩散、吸附机理

运用Boyd液膜扩散公式和范山鹰等提出的扩散模型,考察了碱性溶液中铜、锌氰配合物在离子交换纤维上的扩散行为;通过分析吸附前后纤维上官能团的位置变化以及解吸前后纤维上元素含量的变化,研究铜、锌氰配合物在纤维上的吸附机理。实验结果表明,离子交换纤维对铜、锌配合物的吸附在反应初期,以液膜扩散为主控制步骤,反应后期,以空隙扩散为主控制步骤。并运用离子交换纤维在水溶液中具有类似胶体型物质的双电层结构解释了不同控制阶段吸附速率不同的原因,虽然各阶段吸附速率有所不同,但纤维对铜、锌氰配合物的吸附均为离子交换机制。