CHEMICAL ENGINEERING SCIENCE
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2021
·
IF 4.311
Yong Suo,Yongsheng Ren
The influence of representative typical pollutants in the zero-discharge process of coal chemical high-salty wastewater on the fouling behavior of nanofiltration membranes was studied. In this study, a commercially available NF90 nanofiltration membrane was selected, with three inorganic salts, cyclohexanol (C 6 H 12 O) and APAM as the main target foulants. Various membrane samples were characterized by Contact angle, AFM and SEM-EDS, and the membrane fouling behavior was quantitatively evaluated by analyzing the influence of the interaction between different components in the feed solution on the membrane flux and interface thermodynamics. The results show that the deposition of fouling is closely related to the interface free energy (ΔG). The AB interfacial energy significantly affects membrane fouling. Membrane fouling is mainly dominated by residual APAM, followed by inorganic salts and cyclohexanol. The interaction between organic and inorganic fouling is the core factor that exacerbates membrane fouling. The interaction between APAM and inorganic salt ions mainly accelerates membrane fouling through charge shielding and complexation. Cyclohexanol accelerates membrane fouling mainly by reducing the solubility of inorganic salts and absorbing on the surface of the fouling layer. The competition and synergy between hydrophilic APAM and hydrophobic cyclohexanol are also the factors that aggravate membrane fouling.
研究领域:
环境科学
·
化学工程
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DOI
高影响因子
WATER SCIENCE AND TECHNOLOGY
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2017
·Vol. 75
·期 8
·1982-1989
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IF 1.197
Zhang Ruijun,Yuan Shengnan,Shi Wenxin,Ma Cong,Zhang Zhiqiang,Bao Xian,Zhang Bing,Luo Yan
With the purpose of improving the ultrafiltration (UF) efficiency, anionic polyacrylamide (APAM) has been used as a coagulant aid in the flocculation-UF process. In this study, the impact of APAM on UF efficiency has been investigated with regard to membrane fouling, membrane cleaning and effluent quality. The results indicated that the optimal dosage of APAM had positive impacts on membrane fouling control, membrane cleaning and effluent quality. According to the flux decline curve, scanning electron microscopy and contact angle characterization, the optimal dosage of APAM was determined to be 0.1 mg/L coupled with 2 mg/L (as Al 3+ ) poly-aluminium chloride. Under this optimal condition, membrane fouling can be mitigated because of the formation of a porous and hydrophilic fouling layer. APAM in the fouling layer can improve the chemical cleaning efficiency of 0.5% NaOH due to the disintegration of the fouling layer when APAM is dissolved under strong alkaline conditions. Furthermore, with the addition of APAM in the flocculation-UF process, more active adsorption sites can be formed in the flocs as well as the membrane fouling layer, thus more antipyrine molecules in the raw water can be adsorbed and removed in the flocculation-UF process.
研究领域:
环境工程
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水处理技术
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膜科学
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高分子材料在水净化中的应用
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DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2026
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IF 10.6
Hailin Yu,Hao Wang,Huili Zhang,Guolin Jing,Hongsheng Liu,Zhengnan Sun,Yang Liu,Jianqi Xu,Yihai Yang
With the continuous advancement of oilfield extraction technologies, the volume of oily sewage generated has increased substantially. Such wastewater typically contains high concentrations of suspended solids and emulsified oil. At present, coagulation–flocculation remains the fastest and most practical purification method. The traditional coagulants mainly achieve the destabilization of colloidal particles by introducing a large amount of positive charges. However, this method will result in the formation of excessive flocs, thereby increasing the complexity of the subsequent separation process. To address these limitations, an innovative strategy was proposed in which the quaternary ammonium salt surfactant (OTAB) was incorporated to prepare a novel composite coagulant. At an optimal dosage of 90 mg/L, the residual turbidity of the oily sewage decreased to 16.7 NTU, while the demulsification rate reached 92.44 %. During the coagulation process, the Zeta potential increased but remained below the isoelectric point. Unlike traditional flocculants, OTAB promotes the partial precipitation of anionic polyacrylamide (APAM), and the precipitated APAM continues to participate in flocculation in the presence of polyaluminum silicate sulfate (PASSi). By analyzing changes in polymer content, hydrodynamic radius, molecular weight, and heat absorption–release behavior of APAM after coagulation treatment, the interaction mechanism between ionic species and APAM was elucidated. Furthermore, variations in floc size, morphology, and water surface tension were examined to clarify the action mechanism of the prepared flocculant. The results indicate that the coagulation process is dominated by bridging adsorption, accompanied by partial charge neutralization.
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PubMed
高影响因子
Polymers
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2024
·Vol. 16
·期 12
·1678
·
IF 4.7
Yueyue Wang,Pu Ma,Jun Huang,Lifang Guo,Yu Wang,Huamin Zhai,Hao Ren
As increasing fiber hydrophobicity can significantly improve the paper dewatering process, we found that replacing SBKP and HBKP with 0.5% superhydrophobic CPGMA can significantly improve the dewatering of paper sheets. Therefore, it can be concluded that if CPGMA has little effect on paper properties, it will have potential industrial value in the papermaking industry. Consequently, it is necessary to further study the effect of the CPGMAs@CPAM/SiO2/APAM system on paper properties. To evaluate the application potential of the system in the papermaking industry, we investigated the effects of CPGMAs, which replaced the fibers in the stocks, on the paper properties in the CPAM/SiO2/APAM system. The findings demonstrate that as the CPGMA replacement increased, the paper’s tensile strength, bursting strength, tear resistance, and folding endurance all declined. The trend can be segmented into two phases: a rapid decrease for substitution amounts below 0.5% and a gradual decline for substitution amounts exceeding 0.5%. When replaced with a small amount of CPGMAs, there was a negligible effect on these properties. Second, the paper air permeability increased with the CPGMA substitution amount in the stock. Furthermore, the trend of paper air permeability can be divided into two stages—a rapid stage with a substitution amount of <0.5% and a slow stage with a substitution amount of >0.5%. A small amount of CPGMAs could distinctly improve the paper’s air permeability. Third, CPGMAs, which replaced fibers in the stock, minutely affected the paper formation. A small amount of CPGMAs substantially boosted the efficacy of the process of paper manufacture and certain characteristics of the paper, and it had a negligible impact on the strength of paper. The CPGMAs@CPAM/SiO2/APAM technology has the potential to improve the retention and filtration performance of CPAM/SiO2/APAM.
研究领域:
材料科学
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造纸工程
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产品关联
DOI
PubMed
高影响因子
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