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Zheng Y.,Key Laboratory of Marine Chemistry Theory and Technology | Zheng Y.,Ocean University of China | Gao X.,Key Laboratory of Marine Chemistry Theory and Technology | Gao X.,Ocean University of China | And 4 more authors.
RSC Advances | Year: 2015

In this study, a laboratory-scale electrodialysis (ED) system with an effective area of 88 cm2 was used to remove copper and cyanide in simulated and real gold mine effluents. The membrane fouling was characterized by FTIR, SEM-EDX, membrane resistance measurements and static contact angle. The effects of applied voltage, initial concentration, and flux rate on the removal rate of copper and cyanide were investigated. The highest copper (99.41%) and cyanide (99.83%) removal rates were achieved under the following conditions: applied voltage of 25 V, initial concentration of C2 (concentration of copper and cyanide were 47 mg L-1 and 242 mg L-1), and a flux rate of 4.17 mL s-1. In addition, the lowest concentration of copper (0.44 mg L-1), cyanide (0.48 mg L-1) and zinc (0.34 mg L-1) in the treated effluent were all below regulatory limits (copper, cyanide <0.5 mg L-1, zinc <2.0 mg L-1). The results showed the presence of CuCN, [Cu(CN)3]2-, Cu(OH)2, and Zn(OH)2 in the precipitate, and the fouling of anion-exchange membranes (AEMs) could be decreased significantly via pH adjustment. This research provides a new insight into the removal of copper and cyanide from gold mine effluent. This journal is © The Royal Society of Chemistry 2015.


Wang X.,University of Jinan | Wang X.,Shandong Prov Engin Technology Res Centerfor Ecological Carbon Sink And Capture Utilization | Lu X.,University of Jinan | Xu W.,University of Jinan | And 4 more authors.
Key Engineering Materials | Year: 2014

The 2-thiol benzothiazole was blended in Polyvinylidene fluoride (PVDF) membrane to prepare a kind of PVDF modified ultrafiltration membrane that could be used to remove mercury ion in water treatment. The water flux and retention rate of BSA of obtained PVDF modified ultrafiltration membrane was 222 L/m2·h and 92.33% respectively. The membrane performance were characterized by infrared spectroscopy (FT-IR) and water contact angle measurement. The results showed that, the PVDF modified membrane presented better adsorption ability for mercury ion than the traditional PVDF membrane. After 4 phases of adsorption/desorption, the modified membrane maintained a mercury ion adsorption amount of 0.264 mg/cm2 and the desorption rate could reached 94%. ©2014 Trans Tech Publications Ltd, Switzerland.


Wang L.,University of Jinan | Wang X.,University of Jinan | Wang A.,Shandong Zhaojin Motian Co. | Liu W.,University of Jinan | And 2 more authors.
Key Engineering Materials | Year: 2011

Hydrophilic Polyvinylidene fluoride (PVDF) hollow fiber ultrafiltration membranes were prepared by wet-spinning method. The effects of technical parameters of acrylic acid grafted onto PVDF on the performance of hydrophilic PVDF membranes were investigated via orthogonal test, the technical parameters of preparation of hydrophilic PVDF membranes were determined, and hydrophilic PVDF membranes were prepared. Then hydrophilic PVDF membranes were characterized in terms of breaking strength, breaking elongation, rupture pressure, pure water flux and rejection. The fouling properties and the conditions of acrylic acid grafted onto PVDF were also examined. The results showed that acrylic acid had been grafted onto PVDF, the breaking strength and rupture pressure improved greatly, and the fouling properties were better than PS hollow fiber UF membrane. © (2011) Trans Tech Publications, Switzerland.


Wang L.,University of Jinan | Zhang X.,University of Jinan | Guo S.,University of Jinan | Wang A.,Shandong Zhaojin Motian Co. | And 2 more authors.
Key Engineering Materials | Year: 2011

Hydrophilic Polyvinylidene fluoride (PVDF) flat ultrafiltration membranes were prepared by wet-spinning method. The influence of blending ratio ( the mass ratio of PVDF and PAA), polymer concentration on preparation of blending modified hydrophilic PVDF ultrafiltration membranes were investigated, the technical parameters of preparation of hydrophilic PVDF membranes were determined, and hydrophilic PVDF membranes were prepared. Then, hydrophilic PVDF membranes were characterized in terms of IR spectra, contact angle, scanning electron microscopy images, pure water flux and rejection. The results showed that hydrophilic ultrafiltration membrane could be prepared with PAA and PVDF blends, the hydrophilicity improved greatly, and it was better than traditional PVDF membrane. © (2011) Trans Tech Publications, Switzerland.


Wang L.,University of Jinan | Zhang X.,University of Jinan | Hou S.,University of Jinan | Wang X.,University of Jinan | And 2 more authors.
Advanced Materials Research | Year: 2011

Hydrophilic polyvinylidene fluoride (PVDF) flat ultrafiltration membranes were prepared by wet-spinning method. The effects of technical parameters of acrylic acid grafted onto PVDF on the performance of hydrophilic PVDF membranes were investigated, the technical parameters of preparation of hydrophilic PVDF membranes were determined, and hydrophilic PVDF flat membranes were prepared. Then, hydrophilic PVDF membranes were characterized in terms of pure water flux, contact angle, infrared spectroscopic analysis and scanning electron microscope (SEM). The results showed that acrylic acid had been grafted onto PVDF, and the hydrophilic performance of the modified membrane was better than the traditional one. © (2011) Trans Tech Publications, Switzerland.


Dong S.,Ocean University of China | Zhu W.,Ocean University of China | Gao X.,Ocean University of China | Wang Z.,Ocean University of China | And 3 more authors.
Chemical Engineering Journal | Year: 2016

Tubular porous silicate cement compacts with hierarchical porosity were successfully fabricated via a tert-butyl alcohol (TBA)-based freeze-casting technique in one single step. These samples were characterized by unidirectional aligned pore channels and completely open porosity. Various experimental parameters affecting the macropore size, mesopore size, porosity, and compression strength were investigated, including the initial solids loading, freezing temperature and curing period. Both the research findings of microstructure observations and property tests show that the pore size decreased significantly with decreasing freezing temperature and increasing solids loading. The porosity increased significantly with decreasing solids loading, while the compressive strength decreased remarkably. In addition to their tunable physical characteristics, these brand-new inorganic porous materials with oriented aligned pore channels and dense layer surface showed high permeation performance and desirable separation ability. These results endow the silicate cement, a kind of low-cost and high-performance architecture material, with great potential as a novel ordered porous inorganic material for numerous applications, especially in separation process. © 2016 Elsevier B.V.


Zheng Y.,Key Laboratory of Marine Chemistry Theory and Technology | Zheng Y.,Ocean University of China | Li Z.,State Oceanic Administration | Wang X.,Shandong Zhaojin Motian Co. | And 4 more authors.
Electrochimica Acta | Year: 2015

In this paper, a novel approach of five-compartment electrodialysis was proposed for the treatment of cyanide from gold mine effluent. Two different processing modes were introduced. In mode 1, the cyanide was removed with homogeneous ion exchange membranes and heterogeneous ion exchange membranes respectively. In mode 2, the recovery of cyanide was achieved with homogeneous monovalent anion exchange membranes (1-AEMs) and cation exchange membranes (CEMs). The applied voltage was optimized to improve the removal and recovery efficiency. In addition, pH variation (the recovery of alkaline solution) was investigated. The results showed that the CN- extraction percent of 87.14% was achieved at 30 V applied voltage with the energy consumption of 8.33 kWhm-3 in mode 2. Meanwhile, the removal rate reached up to 97.90% with homogeneous ion exchange membranes at 38 V applied voltage in mode 1, which was much higher than the case of heterogeneous ion exchange membranes (74.02%). Finally, the recovery of alkaline solution was achieved as above and the recovered alkaline solution could be reused for pH adjustment in ED process. This research provides a new insight into the resource recycling of cyanide from gold mine effluent in industrial application. © 2015 Published by Elsevier Ltd.


Wang J.,Ocean University of China | Gao X.,Ocean University of China | Xu Y.,Ocean University of China | Wang Q.,Ocean University of China | And 3 more authors.
Desalination | Year: 2016

This work studied the feasibility of ultrasonic-assisted (US-assisted) chemical cleaning of nanofiltration (NF) membranes that fouled with inorganic scales. We carried out US-assisted acid cleaning experiments by filter arsenic-rich brackish water to investigate the influencing conditions of US-assisted cleaning technology. We first optimized the proper ultrasonic power intensity (1W/cm2) in avoiding of membrane damage. US-assisted water flushing can recover the membrane water flux by around 75%, which suggested that the removal of inorganic scales was inadequate. However, US-assisted acid cleaning is efficient for removing the inorganic scales on membrane surface, and cleaning time was significantly shortened by 1/3 to 2/3 when compared with acid cleaning. It is worth to note that US-assisted acid cleaning can be carried out at a lower pH value of 3.0, while traditional acid cleaning usually conducted at pH of 2.0.This would reduce disposal amount of chemical contaminants by up to 90%. Additionally, our investigation suggests the optimal temperature for US-assisted acid cleaning was around 30°C. This study revealed that the US-assisted acid cleaning method is an effective and environmental-friendly method for NF membrane cleaning. © 2015 Elsevier B.V.


Xu Y.,Key Laboratory of Marine Chemistry Theory and Technology | Xu Y.,Ocean University of China | Gao X.,Key Laboratory of Marine Chemistry Theory and Technology | Gao X.,Ocean University of China | And 6 more authors.
RSC Advances | Year: 2016

Highly stable water permeable thin film MIL-101(Cr) nanocomposite membranes for water treatment were created via in situ interfacial polymerization on a polyether sulfone support. Lab-made MIL-101(Cr) nanoparticles (∼200 nm) were used to introduce direct water channels to a dense polyamide layer, which increased water permeance. On changing the amount and the method of MIL-101(Cr) nanoparticle addition, the surface topography and internal structure of the membranes were changed, leading to different separating properties of the membranes. Measured at 10 bar with 2000 ppm Na2SO4 solution, nanosized MIL-101(Cr) increased water permeance to 3.91 L m-2 h-1 bar-1 at 0.2 w/v%, 158% higher than undoped membranes; meanwhile, high Na2SO4 rejection was maintained. This study experimentally verified the potential use of MIL-101(Cr) in advanced thin film nanocomposite membranes, which can be used in diversified water purification fields, including desalination and the removal of organics. © 2016 The Royal Society of Chemistry.


Wang X.,Ocean University of China | Gao X.,Ocean University of China | Zhang Y.,State Oceanic Administration | Wang X.,Shandong Zhaojin Motian Co. | Gao C.,Ocean University of China
Desalination and Water Treatment | Year: 2016

Batik industries generate large amounts of effluents with high chromaticity, chemical oxygen demand (COD), turbidity, and salinity. The present study aims to recycle batik effluent using nanofiltration (NF) membranes. The effects of various operating conditions on the performances of three NF membranes (NF6, NF2A, and NF3A) were examined in terms of the removal rate of salt, COD, and chromaticity, together with permeate flux. Membrane fouling and cleaning strategies were also investigated. Results showed that the NF3A membrane outperformed the other membranes under the following optimal operating conditions: operating pressure, 1 MPa; operating temperature, 20°C; and cross-flow velocity, 5 m/s. A pilot-scale test was conducted by screening a NF membrane combination, including one NF membrane with high permeate fluxes and a poor water quality and another NF membrane placed on the opposite side, to satisfy reuse requirements and to reduce investment costs. Compared with NF3A membranes alone, the combination of NF2A and NF3A membranes could reduce COD and chromaticity to satisfy the reuse requirement and to enhance water fluxes. Through chemical cleaning with 3.5 ppm EDTA-2Na and 400 ppm NaOH, the performance of the NF membranes could be effectively restored. A feasible NF coupling process was confirmed in batik wastewater reclamation. © 2016 Balaban Desalination Publications. All rights reserved.

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