Selective Recovery of Palladium (II) from Metallurgical Wastewater Using Thiadiazole-Based Chloromethyl Polystyrene-Modified Adsorbent

• Published in: International journal of molecular sciences Vol. 23; no. 20; p. 12158
• Main Authors: Zhang, Xiaoguo, Chen, Zhihong, Wan, Zhaoneng, Liu, Chali, He, Renze, Xie, Xiaoguang, Huang, Zhangjie
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 12-10-2022; MDPI
• Subjects: Activated carbon; Adsorbents; Adsorption; Base metal; Calcium ions; chloromethyl polystyrene; Density functional theory; DFT calculations; Experiments; Ferric ions; Hydrochloric acid; Iron; Lead; Manganese; Membrane separation; Metal ions; Palladium; Palladium - chemistry; Polystyrene resins; Polystyrenes - chemistry; Potassium; Resins; Selective adsorption; separation; Single crystals; Spectroscopy, Fourier Transform Infrared; Spectrum analysis; Thiadiazoles; Wastewater; X-ray diffraction; United States > US; China; Germany; palladium; adsorption; separation; DFT calculations; chloromethyl polystyrene
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms232012158

Selective adsorption of palladium from metallurgical wastewater containing Pt (IV), Rh (III), Ca
, Cu
, Fe
, Ni
, Pb
, V
, and Ti
has tremendous economic and environmental benefits. In this paper, a novel thiadiazole-based chloromethyl polystyrene-modified adsorbent, viz. 2, 5-bis-polystyrene-1,3,4-thiadiazole (PS-DMTD), was synthesized using chloromethyl polystyrene as the backbone. The experimental results show that PS-DMTD can selectively separate Pd (II) from metallurgical wastewater in a one-step adsorption process. The calculated saturation adsorption capacity of PS-DMTD for Pd (II) was 176.3 mg/g at 25 °C. The separation factors of
(M
: Pt (IV), Rh (III), Ca
, Cu
, Fe
, Ni
, Pb
, V
, and Ti
) were all higher than 1 × 10
. FT-IR, XPS, and single-crystal X-ray diffraction showed that the adsorption of Pd (II) to PS-DMTD was primarily through a coordination mechanism. Density functional theory (DFT) calculations revealed that the other base metal ions could not coordinate with the PS-DMTD. Pt (IV) could not be adsorbed to PS-DMTD due to its strong chlorophilicity. Furthermore, Rh (III) existed as a polyhydrate, which inhibited Rh (III) diffusion toward the positively charged absorption sites on the PS-DMTD. These results highlight that PS-DMTD has broad application prospects in the recovery of Pd (II) from metallurgical wastewater.