Enhanced removal of selected hydrocarbons from soil by Pseudomonas aeruginosa UG2 biosurfactants and some chemical surfactants

The ability of rhamnolipid biosurfactants produced by Pseudomonas aeruginosa UG2 to wash a model hydrocarbon mixture from unsaturated soil columns was studied. Both aliphatic and aromatic hydrocarbons were effectively removed without soil clogging with non-recirculating biosurfactant solutions. Recirculation of wash solutions did not substantially affect washing efficiency. Of the several chemical surfactants tested, only Triton X-100 provided comparable hydrocarbon washing efficiency without soil clogging. The results suggest that UG2 biosurfactants have the potential for remediation of hydrophobic pollutants in unsaturated soil.     

Synthetic Peptide templates for molecular recognition: recent advances and applications

The creation of molecular systems that can mimic some of the properties of natural macromolecules is one of the major endeavors in contemporary protein chemistry. However, the construction of artificial proteins with predetermined structure and function is difficult on account of complex folding pathways. The use of topological peptide templates has been suggested to induce and stabilize defined secondary and tertiary structures. This is because the recent advances in the chemistry of coupling reagents, protecting groups, and solid-phase synthesis have made the chemical synthesis of peptides with conformationally controlled and complex structures feasible. Besides their use as structure-inducing devices, these peptide templates can also be utilized to construct novel structures with tailor-made functions. Herein, we present recent advances in the field of peptide-template-based approaches with particular emphasis on the demonstrated utility of this approach in molecular recognition, along with related applications.     

A mathematical model for the production of biosurfactants by Pseudomonas aeuginosa CFTR-6: Production of biomass

The fermentation reaction producing biosurfactant using Pseudomonas aeruginosa CFTR-6 was studied. The progress of the bioreaction was monitored in terms of biomass production, product formation and substrate consumption in shake flask experiments using different initial sugar concentrations. A logistic model for biomass growth was found to be satisfactory. Average estimates of the specific growth rate, biomass yield coefficient and maintenance coefficients were obtained.     

金属-有机框架材料在石化环保领域的应用

石油化工是我国的支柱产业,也是环境污染的主要来源。近年来,随着国家环保形势的日益严峻和相应环保法规的陆续出台,高效处理石化行业所涉及的各类污染问题已成为重中之重。作为一种新型的纳米多孔材料,金属-有机框架（MOF）在石化环保领域展现出了广阔的应用前景。该材料可作为高性能吸附剂、分离膜以及催化材料去除或降解石化行业中的典型污染物。本文系统梳理了MOF材料及其相关工艺在石化环保领域的潜在应用,重点介绍了近年来国内外取得的突破性进展,并在此基础上深入分析了该材料的应用现状、存在问题及未来的研发方向。总体而言,MOF材料具有比传统多孔材料更优异的结构特征和应用性能;展望未来,其能够作为吸附剂、分离膜或是催化材料在石化环保领域得到更大规模的推广与应用。     

Analysis of the Genome of the Heavy Metal Resistant and Hydrocarbon-Degrading Rhizospheric Pseudomonas qingdaonensis ZCR6 Strain and Assessment of Its Plant-Growth-Promoting Traits

The Pseudomonas qingdaonensis ZCR6 strain, isolated from the rhizosphere of Zea mays growing in soil co-contaminated with hydrocarbons and heavy metals, was investigated for its plant growth promotion, hydrocarbon degradation, and heavy metal resistance. In vitro bioassays confirmed all of the abovementioned properties. ZCR6 was able to produce indole acetic acid (IAA), siderophores, and ammonia, solubilized Ca₃(PO₄)₂, and showed surface active properties and activity of cellulase and very high activity of 1-aminocyclopropane-1-carboxylic acid deaminase (297 nmol α-ketobutyrate mg⁻¹ h⁻¹). The strain degraded petroleum hydrocarbons (76.52% of the initial hydrocarbon content was degraded) and was resistant to Cd, Zn, and Cu (minimal inhibitory concentrations reached 5, 15, and 10 mM metal, respectively). The genome of the ZCR6 strain consisted of 5,507,067 bp, and a total of 5055 genes were annotated, of which 4943 were protein-coding sequences. Annotation revealed the presence of genes associated with nitrogen fixation, phosphate solubilization, sulfur metabolism, siderophore biosynthesis and uptake, synthesis of IAA, ethylene modulation, heavy metal resistance, exopolysaccharide biosynthesis, and organic compound degradation. Complete characteristics of the ZCR6 strain showed its potential multiway properties for enhancing the phytoremediation of co-contaminated soils. To our knowledge, this is the first analysis of the biotechnological potential of the species P. qingdaonensis.     

Pyroresistivity in conductive polymer composites: a perspective on recent advances and new applications

Conductive polymer composites (CPCs) with pyroresistive behaviour are of interest for a wide variety of applications such as safe batteries, resettable fuses, temperature sensors and self‐regulating heating devices. Due to their ease of processing, low density, tunable electrical properties, good oxidation resistance, and good flexibility and toughness, CPCs have become the preferred choice of pyroresistive materials in a number of applications. The pyroresistive behaviour of CPCs can be tuned to satisfy the specific requirements of different applications. In this perspective paper, recent progress in the use of pyroresistive CPCs is reviewed. In particular, various factors influencing their performance are discussed and compared, in connection with the associated application, with a special focus on reproducibility and positive temperature coefficient intensity levels. Some of the remaining challenges are identified, together with future prospects in this evolving field. © 2018 Society of Chemical Industry     

土壤、地下水中重金属和多环芳烃复合污染及修复研究进展

随着人们对环境污染调查研究的不断深入,对其认识也不断加深。目前,仅对某单一污染物的研究已经无法解决日趋复杂的环境污染问题,多种污染物的复合污染得到越来越多的关注。重金属和多环芳烃是环境中常见的污染物,其复合污染的情况在环境中广泛存在,而且二者之间复杂的相互作用,增加了复合污染的修复难度。土壤和地下水是重金属和多环芳烃的主要富集场所,同时也是生物生存的重要依托,一旦被污染将严重威胁人类及其他生物的生存。对重金属和多环芳烃复合污染的来源、分布、迁移、转化及其生态毒性进行了介绍,简要概括了重金属和多环芳烃复合污染之间的相互作用机理及其修复方法,并对重金属和多环芳烃复合污染的进一步研究提出展望。     

糖脂类生物表面活性剂的性质及其潜在应用进展

与化学合成的表面活性剂相比微生物产生的生物表面活性剂具有表面活性高、良好的抑菌作用以及环境友好等独特的性质。其中糖脂类生物表面活性剂由于其高产量和多功能生化特性,成为最有发展前途的生物表面活性剂之一。本文综述了糖脂类生物表面活性剂的特性及潜在的应用。     

Review on recent advances of zinc substituted cobalt ferrite nanoparticles: Synthesis characterization and diverse applications

Researchers have taken a prodigious consideration in characterizing and synthesizing zinc substituted cobalt ferrite nanoparticles because of their substantial applications across diverse technological and industrial fields. Zinc substituted cobalt ferrite nanoparticles are a class of lenient magnetic nanomaterials, which have potentially high magnetic, optical, electrical, and dielectric properties. These properties include a high value of permeability, low power losses, permittivity, saturation magnetization, coercivity, resistivity, and other beneficial properties that make them promise candidates for applications in various fields. These ferrites are also used in biomedical areas such as MRI and cancer treatments. In electronic fields, zinc substituted cobalt ferrite nanoparticles are used to make transducers, transformers, biosensors, and sensors. Apart from these advantages, they are found in our everyday electronic and electrical appliances like LED bulb, refrigerator, mobile charger, TV, microwave oven, juicer, washing machine, mixer, iron, printer, laptop, mobile, desktop, etc. Hence, the current review reports some properties of these spinel ferrites and emphasizes the different synthesis techniques that can be used to prepare them. Afterward, the impact of dopant on the materials' properties, the characterization techniques, and the momentous application in the present era have been well discussed.     

Biosurfactant Mediated Biosynthesis of Selected Metallic Nanoparticles

Developing a reliable experimental protocol for the synthesis of nanomaterials is one of the challenging topics in current nanotechnology particularly in the context of the recent drive to promote green technologies in their synthesis. The increasing need to develop clean, nontoxic and environmentally safe production processes for nanoparticles to reduce environmental impact, minimize waste and increase energy efficiency has become essential in this field. Consequently, recent studies on the use of microorganisms in the synthesis of selected nanoparticles are gaining increased interest as they represent an exciting area of research with considerable development potential. Microorganisms are known to be capable of synthesizing inorganic molecules that are deposited either intra- or extracellularly. This review presents a brief overview of current research on the use of biosurfactants in the biosynthesis of selected metallic nanoparticles and their potential importance.     

Molecular design,synthesis strategies and recent advances of hydrogels for wound dressing applications

With the changes in the modern disease spectrum, pressure ulcers, diabetic feet, and vascular-derived diseases caused refractory wounds is increasing rapidly. The development of wound dressings has partly improved the effect of wound management. However, traditional wound dressings can only cover the wound and block bacteria, but are generally powerless to recurrent wound infection and tissue healing. There is an urgent need to develop a new type of wound dressing with comprehensive performance to achieve multiple effects such as protecting the wound site from the external environment, absorbing wound exudate, anti-inflammatory, antibacterial, and accelerating wound healing process. Hydrogel wound dressings have the aforementioned characteristics, and can keep the wound in a moist environment because of the high water content, which is an ideal choice for wound treatment. This review introduces the wound healing process and the development and performance advantages of hydrogel wound dressings. The choice of different preparation materials gives the particularities of different hydrogel wound dressings. It also systematically explains the main physical and chemical crosslinking methods for hydrogel synthesis. Besides, in-depth discussion of four typical hydrogel wound dressings including double network hydrogels, nanocomposite hydrogels, drug-loaded hydrogels and smart hydrogels fully demonstrates the feasibility of developing hydrogels as wound dressing products and their future development trends.     

Dividing wall columns: Fundamentals and recent advances

Different distillation sequences for the separation of near-ideal multicomponent mixtures have been proposed in the past. These sequences included both conventional and thermally coupled distillations. Investigations of these sequences based on thermodynamics and steady-state simulations aimed for identifying the economic and energetic favourable configuration. Dividing wall columns have shown to be superior to conventional distillation sequences in certain cases. For this reason dividing wall columns gained increasing application in the last years. More than 90 applications in production scale are known. The advantages are obvious. Depending on the case considered the energy and investment costs are reduced up to 30% compared to conventional technologies. The footprint is significantly smaller. Also advantageous is the higher flexibility of these systems in comparison to conventional column sequences. For temperature-sensitive products the thermal stress is reduced since the product is reboiled only once. Especially for high price products the product quality can be raised by simultaneously increasing the separation yield.     

Applications of polymer blends: Emphasis on recent advances

In the past decade, polymer blend technology has achieved an important position in the field of polymer science. With increased academic and industrial research interest, the application of polymer blend technology to commercial utility has grown significantly. This review on the applications of polymer blends will cover the major commercial blends in the categories of styrene-based polymer blends, poly(vinyl chloride) blends, polyacrylate blends, polyester and polycarbonate blends, polyolefin blends, elastomer blends, polyelectrolyte complexes, and interpenetrating polymer networks. New developments in polymer blend applications will be discussed in more detail. These systems include linear low-density polyethylene blends with either low- or high-density polyethylene, styrenemaleic anhydride terpolymer/ABS (acrylonitrile-butadiene-styrene) blends, polycarbonate/poly(butylene tetephthalate) blends, new PPO/polystyrene blends, and tetramethyl bisphenol A polycarbonate/impact polystyrene blends. Areas for future research to enhance the potential for polymer blend applications will be presented. The need for improved methods for predicting miscibility in polymer blends is discussed. Weldline strength is a major property deficiency of two-phase systems (even those with mechanical compatibility), and future research effort appears warranted to resolve this deficiency. The use of polymeric compatibilization additives to polymer blends has shown promise as a method to improve mechanical compatibility in phase-separated blends, and will be expected to be the subject of future research programs. Finally, the reuse of polymer scrap is discussed as a future application area for polymer blends. Unique applications recently proposed for polymer blends include immobilization of enzymes, permselective membranes, reverse osmosis membranes, selective ion-exchange systems, and medical applications using polyelectrolyte complexes.     

Graphene: nanoscale processing and recent applications

One of the most interesting features of graphene is the rich physics set up by the various nanostructures it may adopt. The planar structure of graphene makes this material ideal for patterning at the nanoscale. The breathtakingly fast evolution of research on graphene growth and preparation methods has made possible the preparation of samples with arbitrary sizes. Available sample production techniques, combined with the right patterning tools, can be used to tailor the graphene sheet into functional nanostructures, even whole electronic circuits. This paper is a review of the existing graphene patterning techniques and potential applications of related lithographic methods.     

生物表面活性剂及其在石油与环保中的应用

介绍了生物表面活性剂的基本特性、类型、生产及其在石油与环境领域中的应用     

Some recent advances in polyolefin functionalization

Polyolefin‐based materials are increasingly being used in many industrial applications for packaging, automotive and construction materials. The recent developments of research have been aimed at making these materials, often complex, being mixtures, block copolymers, micro‐ and nanocomposites with inorganic and organic fillers, more efficient and environmentally friendly (through recycling processes, and the use of bio‐polyolefins). In this context, functionalized polyolefins, on the one hand, play a fundamental role in improving the morphology and thus the thermal and mechanical properties of heterophase systems, and, on the other hand, provide new materials difficult to obtain by conventional synthesis in connection with the type of inserted functionality. Therefore it appears to be of interest to report and discuss here the recent results concerning the radical grafting in the melt of different functionalities onto polyolefins as well as the capability reached of modulating ad hoc the degree of grafting and the final structure/architecture of functionalized polyolefins. © 2013 Society of Chemical Industry     

Industrial applications of the agglomeration process

Environmental, technological and economic problems caused by utilization of low quality and low rank coals and serious concerns related to a growing number of polluted industrial waste sites have significantly increased interest in further development and application of oil agglomeration technology. Study performed at the Alberta Research Council on the various applications of the spherical agglomeration process led to the development of different technologies applicable for coal cleaning, upgrading, handleability improvement or moisture reduction. The other important applications were recovery of combustible material from rejects and settling ponds and remediation of soils contaminated with various hydrocarbons.

The preparation and handling of fine coal is a key issue to many coal mine operators and the efficient recovery of coal from fines streams could have a profound effect on increased plant productivity and reduction of the potential environmental liabilities associated with waste generation, accumulation and disposal.

To overcome the problems associated with coal fines and hydrocarbon-contaminated soils, ARC researchers have, over the last 20 years, placed particular emphasis on the development and testing of improved coal preparation and soil remediation technologies.