FUEL
·
2023
·
IF 7.4
Suqian Gu,Zhiqiang Xu,Yunxiang Dai,Yang Chen,Yangguang Ren,Yanan Tu,Le Yang,Mengyun Shi
Coal gasification wastewater (CGW) as a substitute for clean water to prepare coal water slurry, which serves as gasification/combustion feedstock, can simultaneously achieve wastewater management and resource utilization. The purpose of this work was to investigate the effects of internal components (i.e., oils, phenols, nitrogen heterocyclic compounds, and inorganic cations) in CGW on the slurryability and dispersion/aggregation behavior of lignite and their co-slurrying mechanisms through experimental and the extended DLVO (eDLVO) theoretical calculations. Results showed that compared to lignite water slurry (LWS), the maximum solids concentration ( ω max ) of coal gasification wastewater slurry (CWWS) increased by 0.80%, with a lower pseudo-plasticity. The organic compounds adsorbed competitively on the hydrophobic regions of lignite improved the slurrying capability of CWWS by decreasing the wettability, Zeta potential, roughness and pore structure of the particles. By contrast, the static stability of CWWS decreased, and its kinetic stability index ( TSI ) increased from 0.23 to 0.33. From the backscattering spectra, dodecane caused the creaming process of the slurry, while the clarification process was attributed to phenol and nitrogen heterocyclic compounds. Inorganic cations, especially NH 4 + and Ca 2+ , significantly reduced the hydrophilic and negative charges on the particle surface, which were the main unfavorable factors leading to particle aggregation and sedimentation. The eDLVO theoretical calculation results exhibited that inter-particle interaction in CWWS was determined by the hydrophobic energy ( E h ) and electrostatic energy ( E e ) and their dropped from 1.79 × 10 −16 J and 5.16 × 10 −17 J to −4.67 × 10 −16 J and 2.59 × 10 −17 J respectively.
研究领域:
环境科学
·
能源工程
✓ 已验证
DOI
高影响因子
Minerals
·
2021
·Vol. 11
·期 1
·58
·
IF 2.644
Yinfei Liao,Xingwei Song,Maoyan An,Zhe Yang,Xiaodong Hao,Hourui Ren
The wetting film evolution process is essential for flotation, especially in bubble–particle attachment. A mixed collector has been proved effective in promoting flotation. In this paper, the effect of a mixed collector (MC) composed by n-dodecane (D) and oleic acid (OA) on wetting film evolution was investigated using the extended Derjagin–Landau–Verwey–Overbeek (EDLVO) theory, the Stefan–Reynolds model, induction time, and zeta potential measurement. The hydrophobic force constant between bubble and coal treated by different collectors was analyzed. The results showed that MC was superior in reducing the induction time and increasing the zeta potential. When bubbles interacted with coal treated by MC, they had relatively low interaction energy, high critical film thickness, and high drainage rate. The order of hydrophobic force constant was no reagent < D < OA < MC. It indicated that the hydrophobic interaction between bubbles and coal particles treated by MC was the strongest because of the synergistic effect of D and OA.Keywords:wetting film;EDLVO theory;Stefan–Reynolds model;collector;hydrophobic force constant
研究领域:
矿物加工工程
·
界面化学
✓ 已验证
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2018
·
IF 6.578
Wanyi Fu,Lan Wang,Fangjuan Chen,Xuezhi Zhang,Wen Zhang
To unravel fouling and defouling mechanisms of protein, saccharides and natural organic matters (NOM) on polymeric membrane during filtration, this study investigated filtration characteristics on polyvinyl chloride (PVC) ultrafiltration membranes with bovine serum albumin, dextran , humic acid as model foulants. Membrane fouling and defouling performances were analyzed through monitoring the flux decline during filtration and flux recovery during physical backwash. Physico-chemical properties (e.g., hydrophobicity and surface charge) of PVC membrane and foulants were characterized, which were used in the extended Derjaguin–Landau–Verwey–Overbeek (EDLVO) theory to calculate the interaction energies between membrane-foulant and foulant-foulant. The results showed that at the later filtration stages the fouling rate was strongly correlated with the deposition rate , which was determined by the interaction energy profile calculated by EDLVO. Moreover, the adhesion forces of membrane–foulant and foulant–foulant were further measured by atomic force microscopy (AFM) with modified colloidal probes. A positive correlation ( R 2 = 0.845) between particle detachment rate (determined by adhesion force) and defouling rate was developed for BSA and HA foulants that led to cake layer formation. By contrast, dextran defouling rate was off this correlation as dextran partially clogged membrane pores due to its smaller size.
研究领域:
环境科学
·
膜分离技术
·
高分子材料
·
胶体与界面化学
·
水处理
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Hongyu Sun,Xin Ma,Lingyun Fei,Zhanfang Cao,Hong Zhong,Shuai Wang
Efficient recovery of fine mineral particles is challenging for minerals flotation due to a small particle mass and high specific surface area. This work innovatively applied a multifunctional surfactant 2-dodecanoylamino-pentanedioic acid (DPA) for achieving flocculation and recovery of fine rhodochrosite. Interestingly, the formation of larger aggregation induced by DPA, instead of sodium oleate (NaOL), was observed and the medium particle size ( d 50 ) was 2.29 times than that of NaOL, resulting in more strong collecting ability for fine rhodochrosite particles (with a recovery of 82.5% for 0.1 mmol/L DPA and 35.3% for 0.1 mmol/L NaOL). Analysis with EDLVO theory illustrated that the hydrophobicity force is one of the factors that induces hydrophobic flocculation, along with electrostatic repulsion, the Van der Waals force, and weak interaction. Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, and density functional theory calculations revealed the “weak-to-medium” hydrogen bond formation among the amide groups or amide and carboxyl functional groups in the DPA complex, further enhancing aggregation between rhodochrosite fine particles. These discoveries are beneficial for providing new insights into aggregation generation among fine particles in the presence of surfactants containing multiple functional groups.
研究领域:
材料科学
·
化学工程
·
矿物加工
·
表面化学
✓ 已验证
产品关联
DOI
高影响因子
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