用2种不同的方式改写以下段落以避免重复同时保持其含义：【1 使用Fe3O4 纳米粒对其进行SiO2 包覆、氨基化修饰以及 DNA 负载得到 DNA-Fe3O4 纳米粒。优化确定 DNA 最佳负载工艺为： DNA 用量 250 mg、 EDC 用量 15 g、 NHS 用量 09 g、反应温度 50℃、反 应时间 6 h此时 DNA 的负载量约为 605 mg·g-1。 2 利用批实验进行 DNA

DNA-Fe3O4 nanoparticles were synthesized by coating Fe3O4 nanoparticles with SiO2, amino modification, and DNA loading. The optimal DNA loading process was determined to be using 250 mg of DNA, 1.5 g of EDC, 0.9 g of NHS, a reaction temperature of 50℃, and a reaction time of 6 h. The resulting DNA loading capacity was approximately 60.5 mg·g-1.

Batch experiments were conducted to study the removal efficiency of CHR by DNA-Fe3O4 nanoparticles, and the factors of contact time, adsorbent dosage, initial CHR concentration, working liquid pH, and ion concentration were investigated. The equilibrium adsorption of CHR in water was achieved within 2 minutes by DNA-Fe3O4 nanoparticles. The removal rate of CHR could reach over 99% by adjusting the dosage of adsorbent for different concentrations. To remove 0.5 mg·L-1 of EtBr in TAE and TBE buffer systems, the concentration of DNA-Fe3O4 nanoparticles should be 2.0 g·L-1, and the removal rate could still reach 99% after three repetitions with 1.0 g·L-1 of DNA-Fe3O4 nanoparticles. The CHR removal rate was higher at pH 7, low ion concentration, and temperature ranging from 4-35℃, while the Dox removal rate was higher at pH 7, ion concentration below 0.01 M, and temperature at 35℃.

The adsorption kinetics of CHR by DNA-Fe3O4 nanoparticles followed a pseudo-second-order kinetic model, while the adsorption isotherm of EtBr followed the Freundlich model. The adsorption process was exothermic, and the interaction between the adsorbent and the adsorbate was electrostatic. The adsorption of CHR by DNA-Fe3O4 nanoparticles at 25℃ and 35℃ followed the Langmiur adsorption model. Overall, appropriate dosage of DNA-Fe3O4 nanoparticles could be used for the treatment of CHR wastewater, which had high efficiency, fast speed, and simple separation process