RADIOCHIMICA ACTA
·
2023
·Vol. 111
·期 6
·459-470
·
IF 1.8
Pan Tan,Xiaoyan Shu,Lingshuang Li,Yanrong Cheng,Du Liu,Xiaoan Li,Xirui Lu,Yi Xie,Shunzhang Chen,Bing Liao,Faqin Dong
The magmatic diagenetic environment was simulated by high-temperature melting and natural cooling. A series of glass-ceramics with different Nd 2 O 3 contents were prepared by using complex component granite (aluminosilicate material). The phase evolution of the matrix at different temperatures was studied by X-ray diffraction (XRD). The structure of glass-ceramics was analyzed by infrared spectroscopy (IR) and scanning electron microscopy (SEM). The mechanical properties of glass-ceramics were also evaluated. The results showed that the glass transition of pure matrix begins at 1200 °C, and the sample with the highest degree of vitrification is obtained at 1500 °C. The addition of Nd 2 O 3 promoted the melting of Fe 3 O 4 crystal, resulting in the complete amorphous matrix when the Nd 2 O 3 amount is in the range of 20–26 wt .%. With the further increase of Nd 2 O 3 content, Nd-bearing feldspar first appeared. No raw material Nd 2 O 3 was found, indicating that the formation of Nd-bearing feldspar may increase the carrying capacity of the material. The Gaussian fitting results showed that the glass-ceramic samples with Nd 2 O 3 content of 29 wt .% are mainly composed of Q 2 and Q 3 structural units. In the EDS result, part of neodymium was clustered with small bright spots, while the spots were uniformly distributed on the sample surface as a whole. Meanwhile, the addition of Nd 2 O 3 increased the mechanical properties of the samples (3.20 g/cm 3 , 8.33 GPa for the sample with 29 wt .% of Nd 2 O 3 ). The results provide a strategy for the treatment of solid waste with radioactive residual actinides.
研究领域:
材料科学
·
核能工程
·
固体废弃物处理
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
·
2023
·
IF 8.8
Chengjie Xue,Long Zhou,Zhanqiang Fang
Hydrophobic organic compounds (HOCs) in e-waste disposal sites are difficult to remove effectively. There is little reported about zero valent iron (ZVI) coupled with persulfate (PS) to achieve the removal of decabromodiphenyl ether (BDE209) from soil. In this work, we have prepared the flake submicron zero valent iron by ball milling with boric acid (B-mZVI bm ) at a low cost. Sacrifice experiments results showed that 56.6% of BDE209 was removed in 72 h with PS/B-mZVI bm , which was 2.12 times than that of micron zero valent iron (mZVI). The morphology, crystal form, atomic valence, composition, and functional group of B-mZVI bm were determined by SEM, XRD, XPS, and FTIR, and the results indicated that the oxide layer on the surface of mZVI is replaced by borides . The results of EPR indicated that hydroxyl radical and sulfate radical played the dominant role in the degradation of BDE209. The degradation products of BDE209 were determined by gas chromatography-mass spectrometry (GC-MS), accordingly, the possible degradation pathway was further proposed. The research suggested that ball milling with mZVI and boric acid is a low-cost means of preparing highly active zero valent iron materials. And the mZVI bm has promising applications in improving the activation efficiency of PS and enhancing the removal of the contaminant.
研究领域:
环境科学
·
化学
✓ 已验证
DOI
PubMed
高影响因子
ENVIRONMENTAL TECHNOLOGY
·
2015
·
IF 1.56
Qunxing Huang,Xu Cai,Moussa Mallaye Alhadj Mallah,Yong Chi,Jianhua Yan
The high concentration of heavy metals in solid wastes may cause serious pollution during thermal treatment. We have investigated, theoretically and experimentally, the effects of several important flue gas species and mineral sorbents on the partitioning behaviour of four major heavy metals (cadmium, lead, zinc and copper) which are often present in municipal solid waste (MSW). Their concentrations in bottom ash, fly ash and flue gas were quantified when model MSW samples were treated thermally under different conditions. The evaporation ratio of the four metals, excluding Cu, increased with decreasing oxygen concentration. The presence of HCl promotes heavy metal evaporation by preventing the formation of stable metallic species, especially for Zn (evaporation of more than 20%). An increase in oxygen concentration has a negative influence on the effect of HCl. In the presence of SO2, Cd and Pb exhibited a higher evaporation ratio, while Zn and Cu were insensitive to the change. SO2 also inhibits Cd vaporization in an oxidative atmosphere. The effect of NH3 on reducing the metal volatilization rate was established indirectly. Calcium oxide addition enhances metal evaporation except for that of Zn (which shows a decrease of 38%). Although desulphurization by calcium injection decreases the volume of acid gas, calcium affects heavy metal pollution control adversely. The presence or addition of SiO2- or Al2O3-containing minerals can lead to the formation of stable metallic salts. This may favour the control of Cd, Pb, Zn and Cu volatilization up to 13%, 50%, 17.5% and 19%, respectively.
研究领域:
环境科学
·
废物处理
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2023
·
IF 6
Bingyang Li,Meiqian Chen
Massive spent ion exchange resins (SIERs) containing radionuclides are produced in nuclear power plants , which need to be treated reasonably. The migration mechanism of nuclides in SIER in both pyrolysis and gasification was evaluated from the chemical equilibrium analysis based on the Gibbs free energy minimization. The maximum volatility degrees of Co, Sr and Cs at 400–600 °C and 0.1 MPa were 0.01%, 0% and 0.1% in the pyrolysis . The maximum volatility degrees of Co, Sr and Cs were 0.015%, 0% and 100% at 600–1300 °C and 0.1 MPa in the gasification, and the steam concentration should be set mainly how to limit the volatilization of radionuclides . To reduce the volatility of nuclides as much as possible, the temperatures should be kept below 600 °C and 870 °C in the pyrolysis and gasification, respectively. The volatilization of Cs was greatly inhibited with lifting the pressure from 0.1 MPa to 1.5 MPa, which decreased from 0.103% to 0.007% in the pyrolysis (600 °C) and from 4.80% to 0.30% in the gasification (715 °C), respectively. Based on preventing the nuclides leakage, the negative pressure in the gasification should be controlled between 0.097 and 0.099 MPa. The volatilization of radionuclides was effectively weakened by adding a fixative, Zr(HPO 4 ) 2 ·H 2 O, since it could be helpful to reduce the gaseous cesium-based products in the pyrolysis and gasification. The volatility degree of Cs was close to 0 if Zr/Cs was great than or equal to 0.5. This study could provide basic data for the pyrolysis and gasification treatment of SIER.
研究领域:
核化学
·
环境工程
·
放射化学
·
废物处理
·
热力学分析
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2022
·
IF 14.224
Jun He,Tao Luo,Zhijian Shi,Irini Angelidaki,Shicheng Zhang,Gang Luo
The inhibition of anaerobic digestion (AD) by phenolic compounds is an obstacle to the efficient treatment of organic wastes. Besides, hydrochar produced from hydrothermal liquefaction of biomass has been previously reported to enhance AD. The present study aimed to provide deep insights into the microbial shifts at the species level to phenol (0–1.5 g/L) inhibition in AD of glucose with and without hydrochar by metagenomic analysis. Phenol higher than 1 g/L had severe inhibition on both the amount and rate of methane production in control experiments, while hydrochar significantly enhanced methane production, especially at phenol 1 g/L and 1.5 g/L. From metagenomic analysis, 78 High-quality metagenome-assembled genomes (MAGs) were obtained. Principal components analysis showed that the microbial communities were shifted when phenol concentration was increased to 0.25 g/L in control experiments and 1 g/L in hydrochar experiments. In control experiments, no MAGs involved in acetogenesis were found at phenol 1.5 g/L and Methanothrix sp.FDU243 was also inhibited. However, hydrochar resulted in the maintenance of several MAGs involved in acetogenesis and Methanothrix sp.FDU243 even at phenol 1.5 g/L, ensuring a persistent methane production. Furthermore, 6 phenol-degrading MAGs were identified, shifting dependent on the concentrations of phenol and the presence of hydrochar.
研究领域:
环境微生物学
·
生物能源
·
宏基因组学
·
废物处理
·
微生物生态学
✓ 已验证
DOI
高影响因子
Journal of Environmental Sciences
·
2018
·
IF 3.12
Yubo Tu,Peiwei Han,Lianqi Wei,Xiaomeng Zhang,Bo Yu,Peng Qian,Shufeng Ye
Large amounts of cyanide tailings are produced during the cyanidation process in gold extraction, which are hazardous solid wastes due to the toxic cyanide. Pyrite is one of the main minerals in cyanide tailings. The removal of cyanide adsorbed on pyrite by H 2 O 2 oxidation under alkaline conditions was investigated in this study. It was found that the removal efficiency was positively correlated with pH from 5 to 12, but remained almost constant when pH was higher than 12. The highest cyanide removal efficiency of 91.10% was achieved by adding no less than 0.6 wt.% of H 2 O 2 . Cyanide removal was positively correlated with the CN − adsorption amount between 1.06 and 8.5 mg/g, and temperature between 25 and 85°C. The removal of cyanide adsorbed on pyrite by H 2 O 2 oxidation under alkaline conditions was due to the oxidation of pyrite. Hexacyanoferrate, thiocyanate and sulfate were generated with mole ratios of about 2.03:1.12:3.17 during the cyanide removal.
研究领域:
环境科学
·
矿物加工
·
废物处理
·
湿法冶金
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2021
·
IF 10.588
Jianwei Zhang,Yuting Wang,Xutong Wang,Wenzhu Wu,Xiaoqiang Cui,Zhanjun Cheng,Beibei Yan,Xiaoe Yang,Zhenli He,Guanyi Chen
The harmless treatment of heavy metal-enriched hyperaccumulator biomass is the main barrier to the industrialization of phytoremediation . Hydrothermal conversion of Sedum alfredii using different solvents (i.e ·H 2 O and HCl) at 210–300 ℃ was performed to investigate the behaviors of Cd and Zn, and the characteristics and potential application of the derived hydrochars were determined. Low temperature and HCl addition favored the removal of Cd/Zn from the solid phase. The highest removal efficiencies of Cd (95.0%) and Zn (89.3%) were achieved at 210 ℃ with the presence of HCl. The yield, pH, ash content, element concentration, functional groups, and crystalline minerals of the derived hydrochar were influenced by the reaction temperature and addition of HCl. The leaching risk of Cd and Zn was significantly reduced by hydrothermal conversion. The addition of HCl facilitated the immobilization of Zn, while it enhanced the mobility of Cd. Moreover, the hydrochar derived at 210 ℃ showed increased sorption capacity towards Cu, and the addition of HCl greatly improved the energy density of hydrochar. These results suggest that HCl-mediated hydrothermal conversion could be a promising technique to achieve the separation of Cd and Zn from hyperaccumulator biomass as well as the production of value-added hydrochar.
研究领域:
环境科学
·
生物修复
·
废物处理
·
生物能源
·
重金属化学
✓ 已验证
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Yang Ren,Chengyang Cao,Hongyun Hu,Su Lei,Xiangzhou Yuan,Xian Li,Hong Yao
Polychloroprene (PCP) rubber is mostly mixed in industrial solid waste (ISW) as the main source of chlorine element. Whereas, the products formation and chlorine behavior during the pyrolysis are insufficiently illustrated for this typical chlorinated polymer, which is not conducive to the chlorine regulation of ISW pyrolytic products. In order to investigate the chlorine transformation behavior, the PCP pyrolysis under the influence of a wide range of heating rates (3–600 °C/min) was conducted to explore the chlorine distribution properties as well as its migration mechanism in the present study. Importantly, 30–65 wt% chlorine was found to be migrated to gas and tar, respectively. Compared with PVC , the differences of chlorine distribution between PCP and PVC may be attributed to the easier cyclization with a longer molecular chain. Also, the release temperature of HCl acted as main component determines its availability for the subsequent formation of chlorinated hydrocarbons. In details, the conversion pathway from chlorinated limonene to Cl-aromatic hydrocarbons was confirmed and the reaction was found to be enhanced at higher temperature and heating rate. By analyzing the content of tar components (especially at low heating rate), it was found that the major formation pathway of aromatic hydrocarbons was supposed to be the direct Diels-Alder reaction of monomer rather than the dechlorination of intermediate chlorinated limonene. Our findings discussed the effect mechanism of heating rate and temperature on chlorine behavior during PCP pyrolysis, providing guidance for the chlorine regulation of ISW pyrolytic products.
研究领域:
环境科学
·
聚合物热解
·
废物处理
·
氯化学
·
热转化
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL TECHNOLOGY
·
2017
·
IF 1.751
Jun Wang,Xu Han,Qunxing Huang,Zengyi Ma,Yong Chi,Jianhua Yan
The migration behaviors of oil, water and solids in sludge during centrifugation were elaborated. Size distribution, surface topography and lypohydrophilic properties were studied in detail. The average size of solids was 61 μm in original sludge, 31 μm in upper layer and 235 μm in bottom layer. The result shows that solvent is essential to separate oil phase into molecular light and weight fractions during centrifugation. With solvent/oil ratio increases from 1:2, 1:1, 2:1 to 5:1, molecular weight in upper layer decreases from 1044, 1043, 1020 to 846 combined with that in bottom layer increases. A model was proposed to calculate the oil residue content in solid phases after sedimentation. The findings of this paper provide information for optimizing the oil recovery and clean treatment.
研究领域:
环境工程
·
石油加工
·
废物处理
·
分离科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）