超声波内环流气升式反应器去除水中苯酚的研究

研究了超声波内环流气升式反应器用于去除水中苯酚的效果与性能。探讨了反应器的表观气速、介质温度对超声-H2O2与超声-H2O2-CuO两种体系对苯酚去除效果的影响。试验结果表明,超声-H2O2-CuO体系对苯酚的去除效果优于超声-H2O2体系,且更能发挥超声与气升式反应器具有流化效果的协同作用。在处理液体积为1000mL、苯酚初始质量浓度为25mg／L、CuO加量为1mg／mL、H2O2加量为300mg／L、声强为4．97w／cm。的条件下,两种体系苯酚的去除率均随反应器的表观气速减小而增大;介质温度从20℃上升到50℃时,超声-H2O2体系苯酚去除率随着温度升高而降低,而超声-H2O2-CuO体系苯酚去除率随着温度升高而增大;反应器中超声-H2O2与超声-H2O2-CuO体系对苯酚的去除过程均符合拟一级反应。     

Competitive Adsorption of Pb(II) and Phenol Onto Modified Chitosan/Vermiculite Adsorbents

Journal of Polymers and the Environment - Many industrial wastewaters are contaminated with both heavy metal ions and organic compounds, posing a major threat to public health and the ecosystem. In...     

Amylose Modified Starches as Superabsorbent Systems for Release of Potassium Fertilizers

Journal of Polymers and the Environment - High-amylose maize starch (AS) was modified by graft copolymerization with sodium acid maleate and disodium maleate, using the KMnO4-NaHSO3 redox system,...     

Immobilization of Horseradish Peroxidase on Macroporous Glycidyl-Based Copolymers with Different Surface Characteristics for the Removal of Phenol

Journal of Polymers and the Environment - Novel macroporous copolymers of glycidyl methacrylate and ethylene glycol dimethacrylate with mean pore size diameters ranging from 150 to...     

催化裂化废水萃取脱酚预处理研究

选用焦化粗柴油为萃取剂,对催化裂化含酚废水进行脱酚预处理,结果表明,最佳萃取条件为：ｐＨ７．０－８．５,温度１５－４０℃,油水体系比１．７－２．１,理论萃取级数４－７级。在上述条件下,出水酚质量浓度为５０ｍｇ／Ｌ。萃取后的粗柴油用于炼油厂加氢精制装置。     

Synthesis and Characterization of Biodegradable Starch-Polyacrylamide Graft Copolymers Using Starches with Different Microstructures

The effects of starch structures, in particular amylose content, on grafting reactions were investigated using thermal gravimetric analysis (TGA), nuclear magnetic resonance, X-ray diffraction (XRD). As a model system, corn starches with different amylose contents (0, 26, 50 and 80 %) were grafted onto acrylamide to produce superabsorbent polymers (SAPs). The weight loss measured by TGA at different temperature was used to analyze the grafting ratio in quantity. In general, the grafting ratio increased (about 10 %) with increasing starch amylose content, and graft chain segment lengths were much lower for the amylopectin-rich (waxy) starch. The high molecular weight and branched structure of the amylopectin reduced the mobility of the polymer chains and increased viscosity, which resulted in resistance to chain growth. The water absorption capability was increased with increasing amylose content for the starch-based SAPs. XRD detection showed that the crystalline structure of all starches was destroyed after grafting reactions. The thermal stability of the polyacrylamide grafted onto the starches increased by about 10 °C, which could be explained by the strong bonding between the grafted polymer chains and the starch matrices.     

Utilization of Triacetylcellulose Waste for the Production of Carbonaceous Adsorbents

Triacetylcellulose(TAC)-based globular activated carbons having the adsorption capacity comparable with commercial ones have been derived using a carbonization system developed for this purpose. The carbonization of TAC proceeds through a liquid phase causing bubbling due to the emission of the decomposition gases. The phosphorus compounds resulting from the starting material of TAC waste promote the activation reactions to produce micro-pores.     

重金属离子天然吸附剂的解吸与再生

总结了重金属离子的天然吸附剂的解吸与再生的研究进展.着重论述了各类解吸剂的解吸原理、解吸特点和解吸性能.指出无机酸解吸剂是价廉高效的理想解吸剂,其中盐酸可在低浓度下达到较高的解吸率,且对吸附剂性能没有损害,而强碱溶液是以阴离子基团形式存在的Cr~(6+)的专有解吸剂.在解吸过程中采用超声波或微波有助于提高解吸率.多数天然吸附剂都具有良好的再生能力,经5次吸附-解吸循环操作仍能保持原有的吸附性能.     

废纸苯酚液化物合成热固型酚醛树脂

为了提高废纸的附加值,利用废纸苯酚液化物与甲醛在碱性环境中反应,进行热固型酚醛树脂合成实验。通过正交实验确定最优化的树脂化合成工艺为:n(甲醛)∶n(废纸液化物)=2.1,n(氢氧化钠)∶n(废纸液化物)=0.5,合成温度74℃,合成时间3.0h。在此工艺条件下制备的酚醛树脂压制的胶合板达到GB/T9846—2004《人造板及饰面人造板理化性能试验方法》中Ⅰ类胶合板的强度要求。     

Crosslinked Polyacrylamide Composite Hydrogels Impregnated with Fly Ash: Synthesis,Characterization and Their Application as Fractures Sealant for High Water Producing Zones in Oil and Gas Wells

Polymeric hydrogels are designed to serve many purposes in various fields of human endeavor. Herein, crosslinked polyacrylamide (PAM) composite hydrogels impregnated with coal fly ash (CFA) were synthesized, characterized and tested as fracture sealing agents in high water producing permeable zones in petroleum industry. The concept of utilizing CFA as an inorganic additive in the matrix of hydrogel emanates from the fact that CFA constitutes majorly alumina and silica. Both chemical oxides can induce the CFA to promote the inherent properties of hydrogel. Polyethyleneimine (PEI) was chosen as the crosslinking agent. Neat PAM/PEI hydrogel and PAM/PEI–CFA hydrogels at various CFA loadings (0.5, 1 and 2 wt%) were synthesized via a transamidation reaction pathway. The developed hydrogels were characterized by hybrid rheometer, FTIR, SEM and XRD instruments. Rheological results reveal that the PAM/PEI–CFA composite hydrogels embedded with various CFA quantities were more elastic than the neat PAM/PEI hydrogel, indicating the dispersion and reinforcing effect of CFA. The functional groups of these hydrogels were confirmed by the FTIR while SEM analysis show that the surface micrographs of neat PAM/PEI hydrogel and PAM/PEI–CFA1 hydrogel were porous in several regions. In contrast, the micrographs of PAM/PEI–CFA2 and PAM/PEI–CFA3 hydrogels demonstrated dense and “net-like” structural patterns. Further, XRD analysis revealed that CFA impregnation has a significant effect on the bulk structural properties of the fabricated hydrogels. The swelling rates of these hydrogels were determined by the gravimetric method and their diffusion parameters evaluated using Fickian diffusion and Schott-order kinetic models. Efficacy of the PAM/PEI–CFA composite hydrogel as fractures sealant in oil and gas wells was conducted at a typical reservoir temperature, 90 °C, and the outcome demonstrated considerable sealing potency.     

Synthesis of Gum Acacia Capped Polyaniline-Based Nanocomposite Hydrogel for the Removal of Methylene Blue Dye

In this research work, a novel gum acacia capped polyaniline-based nanocomposite hydrogel (GPA NCHs) was developed and evaluated for the adsorptive removal of cationic methylene blue dye (MB) from aqueous solutions. Firstly, Gum acacia (GA) capped Polyaniline (PANI) dispersion was synthesized by using dispersion polymerization. Then, a water-swellable hydrogel network consisting of GA-PANI and acrylamide (AM) was obtained by using N,N′ -methylene-bisacrylamide (MBA) as a cross-linker, and ammonium persulphate/N,N,N′,N′-tetramethylethylenediamine (APS/TMEDA) as an initiating system. The developed materials were characterized by UV–visible, FTIR, XRD, SEM–EDX and TEM techniques. The microscopy studies revealed that GA-PANI nanoparticles have a granular morphological surface with an average size of?~?40–100 nm. Removal of MB dye from aqueous system was performed by adsorption studies in batch equilibrium mode with different dosage of GA-PANI, MB concentration, pH and temperatures. The adsorption data revealed that the absorption capacity of GPA NCHs highly depends on the dosage of GA-PANI, pH and concentration of the MB dye. The maximum percentage of MB removal onto GPA 1.0 NCHs was found to be 89% at pH 10 with a dye concentration of 10 mg L^?1. The equilibrium adsorption data were also analyzed by different models to understand the adsorption process. The results revealed that the adsorption process followed the pseudo-second-order kinetics and it fit well in Langmuir and Freundlich adsorption isotherms with a maximum adsorption capacity of 35.41 mg g^?1. These studies demonstrate that the GPA NCHs could be a promising adsorbent material for the removal of MB dye from contaminated aqueous systems.

     

Preparation and Characterization of Three Different Derivatized Potato Starches

The use of native starch as a thermoplastic polymer is limited by its fragility and high water absorption. Due to the presence of several hydroxyl groups in its structure, water acts as a natural plasticizer of starch, modifying its properties. It is necessary to chemically modify starch molecules by replacing hydroxyl groups with other functional groups to reduce water absorption. Chemical modification of starch granules also alters its swelling and gelatinization behavior. In this contribution we describe the chemical modification of starch and its influence on its hydrophilicity and heat resistance. Acetic acid, maleic anhydride and octanoyl chloride were used as derivatizing reagents. The effectiveness of the treatments was evaluated by means of infrared spectroscopy. Different tests were conducted in order to evaluate the influence of the different chemical modifications on starch structure and properties. Results showed that the treatments effectively reduced starch moisture susceptibility, while substantially altering other properties such as amylose content, swelling power, solubility, and heat resistance. Finally, films were prepared from native and derivatized starch and their surface polarity was evaluated.     

Centrifugal Bioreactors and Their Application in Remediation

A new approach to the maintenance of large microbial populations for bioremediation purposes has been developed in which a centrifugal bioreactor is used to immobilize microbial populations at extremely high density. The cells are ordered into a three‐dimensional array through which wastewater or groundwater volumes may be flowed, unimpeded by frits or screens. The process methodology is independent of the type, shape, or viability of the individual cells immobilized and, thus, may be adapted to many different bioremediation needs. The utilization of this new process has been explored for three different types of remediation: the removal of heavy metals from wastewater, the aerobic degradation of methyl‐tert‐butyl ether (MTBE), and the anaerobic reduction of nitrate to nitrogen gas. This article discusses the use of centrifugal bioreactors and their application in remediation. © 2001 John Wiley & Sons, Inc.     

自制Cu-Bi2WO6的表征及其对苯酚的光催化降解

采用水热反应法制备Cu改性的Bi2WO6催化剂(Cu-Bi2WO6).采用XRD仪和紫外-可见光漫反射吸收光谱仪对自制Cu-Bi2WO6的结构进行了表征.考察了光催化降解工艺对Cu-Bi2WO6在可见光下催化氧化降解苯酚效果的影响.实验结果表明:自制Cu-Bi2WO6的吸收边带出现了明显红移,对可见光的利用率较Bi2WO6强;当水热反应pH为0.6时,Cu-Bi2WO6的光催化性能最好;在空气通入量为250 mL/min、Cu-Bi2WO6加入量为1.0 mg/L的条件下,光照反应210 min后苯酚降解率可达92.0％.     

Green Synthesis of Silver Nanoparticles and Study of Their Antimicrobial Properties

One of the major disadvantages of polymers when used in food-contact applications is that they are very susceptible to microbial attack. On the other hand, silver nanoparticles have received increased attention as novel antimicrobial agents. Therefore, the introduction of silver nanoparticles into conventional polymers results in new materials with improved properties. In this investigation, colloidal silver nanoparticles using an environmentally friendly procedure were synthesized. An aqueous solution of AgNO₃ was used as a silver precursor with ‘green’ reducing agents either different types of honey, or β-d-glucose. In the first case, different pH values, as well as the addition of poly(ethylene glycol), PEG were studied, while in the latter, the effect of reduction time in the presence of PEG with various average molecular weights was examined. Properties of the nanoparticles were measured using X-Ray diffraction, UV–Vis and FTIR spectroscopy. Using honey it seems that spherical particles are produced with the smaller average particle size obtained at pH 8.5. Use of honey has the advantage of being a natural product, although its main drawback is that its composition varies and it cannot be predefined to result in reproducible results. Use of β-d-glucose results in stable silver nanoparticles with small average particle size after 24 h reduction. The addition of low molecular weight PEG seems to be beneficial in the production of stable nanoparticles. Finally, the antimicrobial activity of the nanoparticles produced was investigated at different concentrations on both Gram positive and negative bacteria, such as Bacillus cereus, Bacillus subtilis, Escherichia coli and Staphylococcus aureus.     

A Comprehensive Review on the Heavy Metal Removal for Water Remediation by the Application of Lignocellulosic Biomass-Derived Nanocellulose

Journal of Polymers and the Environment - The present review describes the application of lignocellulosic biomass-derived nanocellulose for wastewater remediation with a focus on the removal of...     

膜生物反应器在废水脱氮除磷中的应用

介绍了两种膜生物反应器（MBR）脱氮除磷工艺：单一反应器间歇曝气MBR工艺和厌氧一好氧MBR工艺。总结了MBR脱氮除磷工艺的国内外研究进展、工艺特点及处理效果,重点探讨了MBR脱氮除磷工艺中同步硝化反硝化、短程硝化反硝化及反硝化除磷的机理,并指出了今后MBR脱氮除磷进一步研究的重点及方向。     

旋风分离器压力损失的数学模型及在设计中的应用

从理论上分析了旋风分离器压力损失的成因及影响因素,建立了旋风分离器压力损失的数学模型,解决了旋风分离器设计过程中压力损失的计算问题,将模型应用于实际工业型旋风分离器的设计得到的实际压力损失与数学模型的计算结果吻合良好。数学模型对旋风分离器的设计有较大的参考价值。     

粉煤灰的改性、成型及深度除磷应用

选择合适的改性剂对粉煤灰进行改性,通过有机高分子交联方法对改性粉煤灰进行成型处理,并采用静态吸附法评价改性粉煤灰的深度除磷效果。采用1 g氢氧化铝改性粉煤灰处理100 mL磷质量浓度为10.0 mg/L的模拟废水,磷去除率可达99.70％,处理后模拟废水中磷质量浓度低于0.50 mg/L, 达到GB8978-1996《污水综合排放标准》。成型处理可提高粉煤灰的沉降速率,改善灰水分离效果。经超声再生后的成型氢氧化铝改性粉煤灰的磷去除率仍可达67.9％。     

Synthesis of cellulose-fatty acid esters for use as biodegradable plastics

Long-chain fatty acid carbohydrate esters (FACE) were synthesized by the acid chloride-pyridine reaction to different degrees of substitution (DS). The hydrolyzed soybean oil was used as the source of unsaturated fatty acids. High molecular weight FACE polymers are insoluble in common solvents, such as benzene, toluene, THF, etc., and are highly water resistant. However, FACE polymers of hydrolyzed cellulose (MW 180 kD) are soluble/swellable in toluene and can be cast into tough, flexible films. FACE polymer properties of tensile strength and clasticity vary with degree of substitution and polymer size.Paper presented at the Bio/Environmentally Degradable Polymer Society—Third National Meeting, June 6–8, 1994, Boston, Massachusetts.