Yuzhu Xue,Weinan Wang,Yanhong Zhang,Qinhua Fan,Ying Zhang,Chen Ling,Yuwei Pan
This study proposes a green purification strategy in which mild decomplexation of Ni-EDTA into other Ni complexes facilitates the efficient removal and recovery of nickel through resin adsorption. Decomplexation of Ni-EDTA by boron/Fe 2+ /H 2 O 2 (B/Fe 2+ /H 2 O 2 ) followed by resins adsorption was conducted for Ni(II) removal in Ni-EDTA. The Ni(II) removal efficiency could only achieve 1.3 % and 6.2 % while Ni(II) coexisted with EDTA but more than 10 times of higher when Ni(II) coexisted with EDTA-relatives via the single adsorption of commercial heavy metal-affined resins (D001 and D463), which attributed to the increased binding energies of these Ni-EDTA’s degradation products complexes than Ni-EDTA based on density functional theory (DFT) calculation. In comparing to precipitation, the resin adsorption required much less mineralization of EDTA to have a better removal efficiency of Ni(II). B improved the efficiency of Ni-EDTA decompexation by accelerating the recycle of Fe 3+ /Fe 2+ . The EDTA (and TOC) removal enhanced from 48.7 % (4.7 %) to 94.7 % (11.9 %) by B/Fe 2+ /H 2 O 2 process comparing to Fe 2+ /H 2 O 2 process. With the high EDTA but low TOC removal efficiency after B/Fe 2+ /H 2 O 2 treatment, Ni(II) removal efficiency via resins adsorption could maximum achieve 80.5 %, 2–3 times of that via regular precipitation method. In addition, B and resins exhibited good reusability in five cycles, and B/Fe 2+ /H 2 O 2 -resins process had excellent adaptability to different heavy metal complexes. B/Fe 2+ /H 2 O 2 -D463 system not only could reduce 78.4 % reagents cost compared with that of Fe 2+ /H 2 O 2 -precipitation process, but also could save much cost than other processes. The results provide new insights for the cost-effective treatment of EDTA-complexed heavy metal wastewater.
Oxidation of coal under mild conditions is effective not only to understand the macromolecular network structure of coal but also to produce useful chemicals, allowing more efficient application of coal resources. In this work, the mild oxidation of Zhundong subbituminous coal (ZS) by Fe 2+ /H 2 O 2 system was carried out under various conditions, including [Fe 2+ ]/[H 2 O 2 ] molar ratio, temperature, H 2 O 2 concentration and oxidation time. The liquid oxidation products were analyzed using gas chromatography/mass spectrometry (GC/MS), and the chemical structure changes were studied using Fourier transform infrared spectroscopy (FTIR). The results suggest that the oxidation efficiency of ZS with H 2 O 2 is enhanced with the aid of Fe 2+ . The optimum conditions were determined to be [Fe 2+ ]/[H 2 O 2 ] molar ratio of 0.00453, H 2 O 2 concentration of 3mol/L, 60 oC and 4 h according to the oxidation conversion rate. In total, 25 compounds were identified, which could be categorized as six group components. Most of them are valuedadded chemicals, and the content of benzene carboxylic acids is the highest among them, making up 29.99% of all group components in total relative content (TRC). -CH 2 - should be primary bridge connecting the aromatic rings, and alkylene chains linking three aromatic rings are abundant in ZS.
危险品化学品经营许可证（带存储）