CONSTRUCTION AND BUILDING MATERIALS
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2023
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IF 7.4
Xiaohui Sun,Ziyi Chen,Zongbo Sun,Silin Wu,Keyu Guo,Zijun Dong,Yuansheng Peng
A huge amount of waste slurry generated in the shield tunnelling construction process needs to be utilized or disposed properly. A geopolymeric flocculation-filtration-solidification method (G-FFS) was proposed in this paper. The properties and the dewatering efficiency of the waste slurry conditioned by the cementitious agents and the geopolymeric agents were investigated through filtration under multi-stage pressures. The strength of the filter cake and its microstructures were then investigated. Subsequently, the mechanisms of dewatering and solidification of the waste slurry and the advantages of the G-FFS method in terms of environmental friendliness were discussed. The results show that, with the G-FFS method, the waste slurry with a high water content could be dewatered rapidly and transformed into high-strength building materials (2.47–10.31 MPa). The conditioned slurry also demonstrated a low kinematic viscosity and a low capillary suction time, indicating a better pumpability and dewatering ability. The addition of the sodium dodecyl sulfate (SDS) could improve the dewatering performance further. The hydration of the geopolymeric agent and the high-pressure filtration enhanced the strength of the cake. The densified micro-structure of the filter cake and limited water content led to the difficulty of hydration and, thus, limited the increase of the strength. Compared to the traditional method of utilizing the waste slurry through a cementitious agent, the G-FFS method demonstrates its advantages in efficiency, cost-effectiveness, and environmental friendliness.
研究领域:
土木工程
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
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2023
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IF 7.8
Ce Wang,Yuling Lü,Tianxu Ye,Feng Rong,Limin He
This paper demonstrates flotation separation for dispersed oil droplets and dissolved organics by preparing condensate bubble aphrons (CBA) by partially vaporizing condensate. The results show that the new CBA consists of a condensate membrane and a gas core, with a three-phase contact angle above 140° from the oil surface due to excellent wettability . At different temperatures and condensate compositions, bubbles are about 25–100 µm in size. The half-life time (140–230 s) of CBA and gas hold-up (10–25%) is much higher than nitrogen bubbles. It shows that the CBA has good stability and dispersibility . The flotation experiment of CBA found that the condensate group distribution ratio was optimally adapted to the temperature, and the optimum oil removal efficiency of up to 87% was obtained when the operating temperature was higher than the bubble point of 25–35 °C. The experimental experiment shown the recommended initial oil concentration (400 mg/L) and the mixing ratio of condensate and water (1.0%). Otherwise, CBA flotation efficiency was 10% higher than dissolved gas flotation. With the addition of flocculant , the CBA flotation efficiency can reach 97% of oil droplets and can achieve 50% removal of Acetic acid (HAc).
研究领域:
环境科学
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石油工程
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Environmental Research and Public Health
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2023
·Vol. 20
·期 4
·2793
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IF 4.614
Jie He,Qixuan Song,Jian He
In order to address the growing problem of water pollution caused by the excessive discharge of contaminants and provide a better aquatic ecosystem for the public, increasing attention has been paid to the harmlessness and efficiency of coagulation. In this study, polyaluminum lanthanum silicate (PALS) was synthesized through co-polymerization as a novel coagulant to treat wastewater. FTIR, XRD, and SEM were used to analyze the morphology and structure of the material, which further confirmed that the PALS was successfully synthesized. The results indicated that PALS had a great performance in the treatment of a kaolin–humic acid suspension under the optimal synthesis conditions with Al/Si = 3, La/Si = 0.1, and basicity = 0.7. Compared with conventional coagulants, PALS exhibited a better performance at a low coagulant dose and could achieve a good removal effect for an ultraviolet wavelength less than 254 nm (UV254) (83.87%), residual turbidity (0.49 NTU), and dissolved organic carbon (DOC) (69.57%) at the optimal conditions. Additionally, the PALS showed a better effect on phosphate removal than other coagulants did, where the removal efficiency could reach 99.60%. Charge neutralization and adsorption bridging were the potential wastewater treatment mechanisms employed by the PALS, which showed varied contributions under different pH levels. The results indicated that PALS can be a promising coagulant in water treatment.Keywords:coagulant;water treatment;phosphate adsorption;polymer bridging
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
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2023
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IF 6
Yingxin Chen,Qian Chen,Richard M. Kasomo,Yanfeng Jin,Pujia Yang,Huifang Zheng,Xiaoqing Weng,Hongqiang Li,Shaoxian Song
Adsorption methods have garnered significant attention for fluoride removal from water bodies owing to their superior selectivity, simple operations, and wider applicability. However, the development of adsorbents with higher adsorption performances requires significant attention. Here, graphene oxide is endowed with excellent affinity towards fluoride by doping polyhydroxy complexes onto its surface structure and regulating the potential charge. Multiple detection measurements involving scanning electron microscopy (SEM) equipped with energy-dispersive X-ray spectroscopy (EDS), Brunauer-Emmett-Teller (BET) analysis, X-ray diffraction (XRD), and transmission electron microscopy (TEM) were employed to demonstrate the textural properties of graphene oxide (GO) modified by polyaluminium chloride (HAO@GO). Conversely, the effects of parameters including the preparation conditions, co-existing competitive ions, recyclability, contact time, and initial concentration on the adsorption behaviors were systematically determined. The adsorption experimental data were fitted well by the Langmuir isotherm model and pseudo-first-order model. The calculated maximum adsorption capacity was 129.23 mg/g at room temperature (25 °C) and a pH of 7.00, which is greater than that of most reported adsorbents. The existence of competitive anions, such as NO 3 - , SO 4 2 - , and PO 4 3 - , unavoidably interferes with fluoride adsorption. TEM, zero point of charge test, adsorption isotherm, and X-ray photoelectron spectroscopy (XPS) tests indicated that chemical adsorption and ligand exchange are responsible for the adsorption of fluoride onto HAO@GO.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Sustainability
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2023
·Vol. 15
·期 11
·9060
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IF 3.9
Tingting Zhang,Yanling Yang,Xing Li,Zhiwei Zhou,Bigui Wei
This study investigated the ultrasonic–thermal regeneration of powdered activated carbon (PAC) spent using 4-chlorophenol (4-CP). Similarly, a thermal regeneration process was also studied and the reaction conditions (i.e., regeneration temperature, heating rate, regeneration time) were tested. Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) analysis were applied to characterize the regenerated PACs under different treatments (thermal, ultrasonic and ultrasonic–thermal) and also compare them with the fresh and exhausted PACs. According to our regeneration observations, the ideal regeneration parameters were determined to be a 40 kHz frequency, 0.18 W/mL sonication power, 0.1 M NaOH and 50% (v/v) ethyl alcohol as the regeneration solution, and 1 g/L of saturated PAC mass with thermal regeneration as the second stage at 500 °C, desorbed for 30 min with a heating rate of 20 °C min−1. Under these conditions, the RE value achieved 90.99% and the η value reached 5.6%. The results of FTIR, XPS and XRD revealed that the oxygen functional group content of ultrasonic–thermal regenerated PAC significantly increased. These oxygenous groups exerted a positive effect on the adsorption process of the regenerated PAC and the subsequent adsorption–regeneration process.Keywords:ultrasonic;thermal;regeneration;powdered activated carbon;characteristic
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Arabian Journal of Chemistry
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2023
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IF 6
Panyang Guo,Jie Wang,Yunyan Tie,Xu Luo
In the marine high-pressure low-temperature environment, it is difficult to regulate the low-temperature rheology of the drilling fluid, and the spilled natural gas is easy to generate solid gas hydrate in the wellbore, causing problems such as wellbore blockage and increasing the risk of safe drilling operations. Although there are many researches on the invasion process of drilling fluid and the development of new hydrate inhibition, there is still a lack of research on the inhibition system suitable for drilling fluid. Therefore, this paper uses the self-developed hydrate formation evaluation experimental device to simulate and analyze the effect of inhibitors in reservoir environment and optimize the scheme of drilling fluid inhibition system. The results show that: (1) Through the improvement of the experimental device of water bath methane hydrate (MH) evaluation, the accuracy and parallel control of the equipment are enhanced, and the methane hydrate formed by sea water (SW) is less than that of distilled water (DW), and the structure of methane hydrate formed by distilled water is more compact. (2) Through the evaluation experiment of single inhibitor A3, PAC and CMC inhibition system, it was found that A3 had the best inhibition effect, and when the inhibitor concentration was 1.5 wt%, it had the best inhibition effect. (3) The influence of clay types on the formation of methane hydrate is also significantly different. Bentonite soil Red (BSR) has better inhibition performance than Bentonite soil Yellow (BSY), and its ' hut ' structure formed at low temperature is the reason for the formation of methane hydrate. (4) The inhibition ability of A3 inhibitor in BSY system and BSR system solution in general, the addition of KCl can play a strong synergistic inhibition ability with A3 in BSR system, and its electric field reduces the activation energy of water molecules as well as the consumption of free water is the reason to reduce the generation of methane hydrate.
研究领域:
石油工程
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）