This study aims to treat heavy metal pollutants in water by applying red mud particle waste. An experiment on the static adsorption of heavy metal ions Pb 2 + (or Cd 2 + and Cu 2 + ) by red mud particles was carried out, and the influences of the type of heavy metal ion, ion concentration, pH value, red mud dosage, reaction time, and temperature on adsorption performance were explored. The competitive adsorption mechanisms of various coexisting heavy metal ions by red mud particles were compared. The red mud samples loaded and not loaded with heavy metal ions were detected by zeta potential measurement, scanning electron microscopy, and Fourier transform infrared spectrometry. The adsorption strength of red mud particles for heavy metal ions was ranked in the sequence of Pb 2 + , Cd 2 + , and Cu 2 + , while increasing temperature enhanced their adsorption. When the initial pH values were 4.3, 5.0, and 3.6 for Pb 2 + , Cd 2 + , and Cu 2 + solutions, the removal peaks were 94.5%, 92.8%, and 78.1%, respectively. The preferred order of adsorption for red mud was Pb 2 + , Cd 2 + and then Cu 2 + under the competitive mechanism of binary/ternary systems due to the discrepancy in the functional groups of red mud particles loaded with different heavy metal ions.
Yuchen Li,Zhen Chen,Bingling Yuan,Lei Xing,Guoxiong Zhan,Yue Peng,Lidong Wang,Junhua Li
Using waste red mud as catalysts for enhancing mass transfer and boosting amine-based solvent regeneration is a promising option for both resources recycling and efficient carbon capture. Here, the effect of fine red mud particles was firstly investigated on carbon dioxide (CO 2 ) absorption and desorption. The Brownian motion and shuttle effect of submicron or micron red mud particles play a positive role in reducing the concentration boundary layer and updating the CO 2 -species concentration of liquid/gas film, which is beneficial for mass transfer enhancement. Additionally, the composite metal oxides of red mud support abundant acid/base active sites for water dissociation, which can promote the proton transfer and boost carbamate decomposition. Therefore, the average enhancement factor is ∼1.49 and the average absorption rate increases by 22.8 %; while the maximal desorption rate (2.14 mmol/min) increases by 289 % and relative heat duty decreases by 16.3 %, after adding 2.5–5 % red mud particles. The continuous CO 2 absorption–desorption experiments verify red mud increases the capture efficiency from 51.6 % (blank test) to 62.4 %. The results offer a favorable technology for reuse of industrial solid waste in the field for low-energy carbon capture.
危险品化学品经营许可证（带存储）