Nanomaterials for biofuel production using lignocellulosic waste

Production of biofuels using second-generation, non-food, lignocellulosic waste biomass is a sustainable approach that solve the economic issues of fossil fuels and environmental pollution. The major issues of biofuel production are biomass complexity, pretreatment, enzyme denaturation and cost. This article reviews the application of nanomaterials for biofuel production from various lignocellulosic wastes.     

Nanofertilizers and nanopesticides for agriculture

The excess use of mineral fertilizers and unsafe pesticides has led to pollution and serious health issues. Nanoscience may solve those issues by providing nanomaterials of higher performance. Here we reviewed the development of nanofertilizers and nanopesticides and their applications on crop systems. Nanofertilizers such as N, P, K, Fe, Mn, Zn, Cu, Mo and carbon nanotubes show better release and targeted delivery efficiency. Nanopesticides such as Ag, Cu, SiO₂, ZnO and nanoformulations show better broad-spectrum pest protection efficiency in comparison with conventional pesticides.     

基于土壤模式生物的纳米材料毒理研究进展

随着纳米科技与工业的高速发展,大量的纳米材料被广泛应用并最终汇聚到土壤环境中,对土壤生态和人体健康造成潜在影响。由于土壤生物具有多样性,选择具有代表性、敏感性并便于获取的土壤模式生物作为实验受体进行纳米材料的生物安全评估及环境毒理效应研究尤为重要。较为系统地回顾和总结了几种典型土壤模式生物的特点,为纳米材料毒理研究中受试生物的选择提供参考,在此基础上整理了大量基于典型土壤模式生物的纳米材料毒性研究资料,归纳了不同层次的研究方法,分析探索了纳米材料毒性机理,并展望了未来的研究重点。     

种群水平生态风险评价方法概述及其在环境管理中的应用

生态风险评价的目的是保护生态系统功能的完整性、稳定性和持久性,为环境风险管理提供理论依据。然而,目前常见的用于保护生物的化学污染物浓度阈值大多是以个体水平的毒性试验结果为基础,忽略了物种在时间和空间相互作用等因素,不能够完全保护生态环境安全和生态系统功能的延续性。本文从生态风险评价的概念、目的和意义引出种群水平生态风险评价在环境管理应用的重要性,综述了种群水平生态风险评价的科学问题(如密度依赖、遗传变异和空间结构等),归纳了种群水平风险评价主要模型方法及其应用(如Euler-Lotka方程、预测矩阵、个体模型、空间模型和动态能量预算模型等),列举了各国现有法律法规中关于种群水平生态风险评价的规定,以期为种群水平生态风险评价方法研究及在环境管理中的应用提供有益借鉴。     

碳纳米材料的水环境行为及对水生生物毒理学研究进展

随着纳米科技的迅猛发展,人工碳纳米材料的生产和使用逐年递增,越来越多的碳纳米材料进入水环境中,对水生生物产生毒性效应。本文在介绍了碳纳米球、石墨烯、碳纳米管3种碳纳米材料的基础上,分析了碳纳米材料的水环境行为,重点综述了碳纳米材料对水生生物毒性效应研究现状,以及可能的致毒机制,并指出今后碳纳米材料对水生生物毒理学亟待加强的研究领域。     

Nanomaterials for environmental burden reduction, waste treatment, and nonpoint source pollution control: a review

Nanomaterials are applicable in the areas of reduction of environmental burden, reduction/treatment of industrial and agricultural wastes, and nonpoint source (NPS) pollution control. First, environmental burden reduction involves green process and engineering, emissions control, desulfurization/denitrification of nonrenewable energy sources, and improvement of agriculture and food systems. Second, reduction/treatment of industrial and agricultural wastes involves converting wastes into products, groundwater remediation, adsorption, delaying photocatalysis, and nanomembranes. Third, NPS pollution control involves controlling water pollution. Nanomaterials alter physical properties on a nanoscale due to their high specific surface area to volume ratio. They are used as catalysts, adsorbents, membranes, and additives to increase activity and capability due to their high specific surface areas and nano-sized effects. Thus, nanomaterials are more effective at treating environmental wastes because they reduce the amount of material needed.     

环境毒理学研究进展

综述了近年来环境毒理学的研究进展,内容包括:环境污染物对机体的影响及其环境行为、环境污染物及其转化物的毒性和评估方法、实验室模式生物、生物标志物以及环境毒理学在其他相关学科中的应用等.此外,还对环境化学品管理和安全性评价、Hormesis(兴奋效应)现象、遗传毒性致癌物的危险度评价、室内环境毒理学分析与研究等热点问题进...     

An exploratory study of chemical elements in drinking water and non-Hodgkin's lymphoma

Nanomaterials are widely used in the field of engineering and in modern society. Although the unique characteristics of nanoparticles also enable them to provide environmental solutions to reduce the formation and emissions of pollutants, adverse effects on human health may occur from the exposure to nanomaterials during the manufacturing processes and when nanomaterials are released and they contaminate the environment. It is essential to understand the factors affecting the accumulation, aggregation, deposition, translocation, and distribution of nanomaterials (natural or engineered) in the ecosystem. This study presents an extensive review of the environmental effects of nanomaterials, including classification, adverse impacts on human health and the environment, transport pathways, monitoring methods, and the current regulations regarding nanomaterials. The review indicates that the diversity of nanoparticles and their properties make the identification and characterization of nanomaterials a difficult task, and an improvement in sensitivity and selectivity of analytical methods for detecting nanoparticles in the environment is required. Besides, few regulations have been established for the management of nanoparticles released into the environment. In order to expedite the environmental management of nanomaterials, this study proposes a risk assessment framework based on the findings in the review as a practice alternative for the environmental assessment and effective management of nanomaterials. Development of practical innovative risk-based management measures may help us to find answers to the concerns such as safety of engineering and applying nanomaterials and effective control of nanoparticle contamination in the environment.     

基于模式生物秀丽隐杆线虫的环境污染物生殖毒性研究进展

由于人类社会的发展,环境污染也越来越严重,研究环境污染物对生态及人类健康的影响极为重要。生殖系统是人和动物繁衍后代的重要系统,常见环境污染物对生殖系统的影响正引起研究人员的广泛关注。秀丽隐杆线虫具有身体透明、品系丰富和遗传背景清楚等优点,为生殖毒理学研究提供了一个便利的平台。以秀丽隐杆线虫为模型已对多种环境污染物的生殖毒性进行了评价。本文重点叙述了重金属、纳米材料、有机物等化学污染,辐射、磁场等物理污染,以及病毒等生物污染对秀丽线虫生殖系统的影响,并归纳讨论了环境污染物造成生殖功能障碍的几种主要机制,如氧化应激、DNA损伤、内质网应激以及神经损伤等,但不同类型污染物的毒性效应与其自身的物化性质紧密相关。环境污染物诱导的生殖毒性中不同响应机制之间的关联性、不同发育阶段的敏感性差异、污染物的传代效应以及有效的缓解方式的筛选等都有待进一步的开展。     

典型纳米材料的土壤微生物效应研究进展

纳米材料的大量生产和广泛应用使其不可避免地进入环境中,而土壤是人工纳米材料释放到环境的主要的汇。土壤中的微生物群落能敏感地反映土壤环境质量的变化,其对物质循环与能量转换具有极重要的生态学意义,然而纳米材料因其独特的物理化学特性,对土壤微生物群落及其功能的影响尚不明确。在参考纳米材料对微生物影响相关研究的基础上,总结了土壤中纳米材料的主要类型及来源,综述了典型纳米材料对土壤微生物群落结构、丰度、功能的影响及可能的影响机制,探讨了环境因子对人工纳米材料土壤生物效应的调控作用,对需要深入研究的方向进行了展望。     

包装材料及食品中纳米材料的检测与表征技术

随着纳米技术的发展,纳米材料在包装行业及食品工业中得到了广泛的应用。然而,纳米材料的安全应用高度依赖于对其生物及环境效应的了解。有研究表明,纳米材料对人类健康及生态环境存在着潜在危害,这使得纳米材料的安全性成为毒理学领域的热点研究课题。同时纳米材料的安全性问题也成为纳米复合包装材料及纳米食品研究和开发的新瓶颈。在对纳米材料没有充分认识的情况下,为了消费者和生态环境的安全,必须控制包装材料及食品中纳米颗粒的种类、来源、含量及可能的释放,这就需要可靠的方法对纳米颗粒的性质和结构进行检测及表征。首先,综述了目前纳米材料在复合包装材料及食品加工中的应用,然后总结了包装材料及食品中纳米材料的检测技术及表征方法,例如显微技术、色谱分离技术、光谱与质谱技术等。由于纳米材料的理化性质参数众多,应用多种分析手段来检测和表征纳米材料成为必然。最后对目前检测技术及表征方法的不足和今后发展方向进行了探讨。     

Nanomaterials for agriculture,food and environment: applications,toxicity and regulation

Nanotechnology is expected to have a beneficial influence on agriculture, food and environment, due to the unique properties of nanomaterials. However, little is known about their safety and potential toxicity. Here we review metal nanoparticles, nanometal oxides, carbon nanotubes, liposomes and dendrimers. We present the application of these nanomaterials in agriculture, food and environment for plant protection; disease treatment; packing materials; development of new tastes, textures and sensations; pathogen detection; and delivery systems. We discuss risk assessment of nanomaterials and toxicological impacts of nanomaterials on agriculture, food and environment. We then provide regulatory guidelines for the safer use of nanomaterials.     

Aggregation and dissolution of silver nanoparticles in a laboratory-based freshwater microcosm under simulated environmental conditions

Silver nanoparticles (NP) are used in several applications, including their use as antimicrobial agents in textiles, personal care, and other domestic products. As such, there is a high potential for the release of silver nanoparticles (AgNP) in the aquatic environment. In aquatic ecosystems, nanomaterials are affected by abiotic factors, such as temperature, that alter their chemistry and influence their fate in the environment. Preliminary studies indicate that NP tend to form aggregates which are potentially more recalcitrant than unaggregated NP. These and other fate processes are largely dependent on both the characteristics of the NP and that of the environment. In this study, lab experiments were conducted to investigate the physicochemical properties and temperature solubility of AgNP (<100 nm) that may potentially influence the fate and behavior of AgNP in the aqueous environment. Results indicated that, under these tested conditions, AgNP may be transformed in size and thereby affect fate, bioavailability, and toxicity. In this study, a novel method was used to determine whether AgNP would form agglomerates, or behave as isolated particles, or dissolve when in aqueous media and under different environmental conditions. The new aspects evaluated in this study demonstrated that AgNP are transformed in both size and state under variable environmental conditions.     

Recent advances in antimony removal using carbon-based nanomaterials: A review

• The synthesis and physicochemical properties of various CNMs are reviewed. • Sb removal using carbon-based nano-adsorbents and membranes are summarized. • Details on adsorption behavior and mechanisms of Sb uptake by CNMs are discussed. • Challenges and future prospects for rational design of advanced CNMs are provided. Recently, special attention has been deserved to environmental risks of antimony (Sb) element that is of highly physiologic toxicity to human. Conventional coagulation and ion exchange methods for Sb removal are faced with challenges of low efficiency, high cost and secondary pollution. Adsorption based on carbon nanomaterials (CNMs; e.g., carbon nanotubes, graphene, graphene oxide, reduced graphene oxide and their derivatives) may provide effective alternative because the CNMs have high surface area, rich surface chemistry and high stability. In particular, good conductivity makes it possible to create linkage between adsorption and electrochemistry, thereby the synergistic interaction will be expected for enhanced Sb removal. This review article summarizes the state of art on Sb removal using CNMs with the form of nano-adsorbents and/or filtration membranes. In details, procedures of synthesis and functionalization of different forms of CNMs were reviewed. Next, adsorption behavior and the underlying mechanisms toward Sb removal using various CNMs were presented as resulting from a retrospective analysis of literatures. Last, we prospect the needs for mass production and regeneration of CNMs adsorbents using more affordable precursors and objective assessment of environmental impacts in future studies.     

Urban Fluid Mechanics: Air Circulation and Contaminant Dispersion in Cities

Recently, many urban areas of the world have experienced rapid growth of population and industrial activity raising concerns of environmental deterioration. To meet challenges associated with such rapid urbanization, it has become necessary to implement wise strategies for environmental management and planning, addressing the exclusive demands of urban zones for maintaining environmental sustainability and functioning with minimum disruption. These strategies and related public policy must be based on state-of-the-science tools for environmental forecasting, in particular, on mathematical models that accurately incorporate physical, biological, chemical and geological processes at work on urban scales. Central to such models are the mechanics of environmental fluids (air and water) and their transport and transformation characteristics. Although much progress has been made on understanding environmental flow phenomena, a myriad of issues akin to urban flow, the transport phenomena, air and water quality and health issues (epidemiology) remain to be understood and quantified. We propose to initiate a new focus area – Urban Fluid Mechanics (UFM) – tailored to research on such issues. For optimal societal impact, UFM must delve into fundamental and applied fluid flow problems of immediate utility for the development of urban public policy and environmental regulations. Such efforts often entail the use of `whole' systems approach to environmental studies, requiring careful synthesis between crosscutting areas.In this paper, a few topics in the realm of UFM are presented, the theme being the flow and air quality in urban areas. Topics such as the scales of flow, the atmospheric boundary layer, pollutants and their transport and modeling of flow and air quality are briefly reviewed, discussed and exemplified using case studies. Identification of important flow-related issues, rigorous multidisciplinary approaches to address them and articulation of results in the context of socio-political cause calebre will be the challenges faced by UFM.     

Energy and environmental applications of carbon nanotubes

Energy and environment are major global issues inducing environmental pollution problems. Energy generation from conventional fossil fuels has been identified as the main culprit of environmental quality degradation and environmental pollution. In order to address these issues, nanotechnology plays an essential role in revolutionizing the device applications for energy conversion and storage, environmental monitoring, as well as green engineering of environmental friendly materials. Carbon nanotubes and their hybrid nanocomposites have received immense research attention for their potential applications in various fields due to their unique structural, electronic and mechanical properties. Here, we review the applications of carbon nanotubes (1) in energy conversion and storage such as in solar cells, fuel cells, hydrogen storage, lithium ion batteries and electrochemical supercapacitors, (2) in environmental monitoring and wastewater treatment for the detection and removal of gas pollutants, pathogens, dyes, heavy metals and pesticides and (3) in green nanocomposite design. Integration of carbon nanotubes in solar and fuel cells has increased the energy conversion efficiency of these energy conversion applications, which serve as the future sustainable energy sources. Carbon nanotubes doped with metal hydrides show high hydrogen storage capacity of around 6?wt% as a potential hydrogen storage medium. Carbon nanotubes nanocomposites have exhibited high energy capacity in lithium ion batteries and high specific capacitance in electrochemical supercapacitors, in addition to excellent cycle stability. High sensitivity and selectivity towards the detection of environmental pollutants are demonstrated by carbon nanotubes based sensors, as well as the anticipated potentials of carbon nanotubes as adsorbent to remove environmental pollutants, which show high adsorption capacity and good regeneration capability. Carbon nanotubes are employed as reinforcement material in green nanocomposites, which is advantageous in supplying the desired properties, in addition to the biodegradability. This article presents an overview of the advantages imparted by carbon nanotubes in electrochemical devices of energy applications and green nanocomposites, as well as nanosensor and adsorbent for environmental protection.     

Life cycle analysis and choice of natural gas-based automotive alternative fuels in Chongqing Municipality, China

Road transport produces significant amounts of emissions by using crude oil as the primary energy source. A reduction of emissions can be achieved by implementing alternative fuel chains. The objective of this study is to carry out an economic, environmental and energy (EEE) life cycle study on natural gas-based automotive fuels with conventional gasoline in an abundant region of China. A set of indices of four fuels/vehicle systems on the basis of life cycle are assessed in terms of impact of EEE, in which natural gas produces compressed natural gas (CNG), methanol, dimethylether (DME) and Fischer Tropsch diesel (FTD). The study included fuel production, vehicle production, vehicle operation, infrastructure and vehicle end of life as a system for each fuel/vehicle system. A generic gasoline fueled car is used as a baseline. Data have been reviewed and modified based on the best knowledge available to Chongqing local sources. Results indicated that when we could not change electric and hydrogen fuel cell vehicles into commercial vehicles on a large scale, direct use of CNG in a dedicated or bi-fuel vehicle is an economical choice for the region which is most energy efficient and more environmental friendly. The study can be used to support decisions on how natural gas resources can best be utilized as a fuel/energy resource for automobiles, and what issues need to be resolved in Chongqing. The models and approaches for this study can be applied to other regions of China as long as all the assumptions are well defined and modified to find a substitute automotive energy source and establish an energy policy in a specific region.     

Cement industry: sustainability, challenges and perspectives

Cement-based materials, such as concrete and mortars, are used in extremely large amounts. For instance, in 2009 concrete production was superior to 10 billion tons. Cement plays an important role in terms of economic and social relevance since it is fundamental to build and improve infrastructure. On the other hand, this industry is also a heavy polluter. Cement production releases 5–6% of all carbon dioxide generated by human activities, accounting for about 4% of global warming. It can release huge amounts of persistent organic pollutants, such as dioxins and heavy metals and particles. Energy consumption is also considerable. Cement production use approximately 0.6% of all energy produced in the United States. On the other hand, the chemistry underlying cement production and its applications can be very helpful to overcome these environmental issues. In terms of manufacture, there are many alternative materials that can be used to minimize carbon dioxide production and reduce energy consumption, such as calcium sulfoaluminates and β-Ca₂SiO₄—rich cements. Using residues from other industrial sectors can also improve the sustainability of cement industry. Under adequate conditions, waste materials such as tyres, oils, municipal solid waste and solvents can be used as supplementary fuel in cement plants. Concrete can be used for encapsulation of waste materials such as tyres, plastics and glasses. In this review, we discuss some aspects of the cement industry associated with environmental science. Other issues such as economic aspects, the chemistry of cement manufacture and its properties are also presented. Special attention is given to the role that cement chemistry can play in terms of sustainability. The most relevant aspects are outlined, such as the use of alternative materials, new possibilities and also the recycling of materials. It is also argued that an important aspect is the role of research and development necessary to improve cement sustainability.     

Titanium dioxide nanoparticles: synthesis,characterisations and aquatic ecotoxicity effects

Little information is available on the potential ecotoxicity of nanomaterials in the marine environment. In particular, the aquatic ecotoxicity impact of titanium dioxide (TiO₂) has been rarely reported. To carefully address this issue, we report on the synthesis of TiO₂ NPs using solvothermal process. The structure and morphology of the prepared TiO₂ nanoparticles were characterised using different techniques. To study the potential ecotoxicity effect of TiO₂, antioxidant system of mediterranean bivalves (Mytilus galloprovincialis) was used, measuring three oxidative biomarkers (ROS production, SOD activity and GSH/GSSG level). No considerable effect was found in the digestive glands of any of the groups treated with TiO₂ with concentration gradients ranging from 1 to 100?mg/L. Thus, the level of the superoxide anion, the activity of an antioxidant enzyme superoxide dismutase (SOD) and the GSH/GSSG ratio showed no significantly differences in digestive glands of all treated groups compared to the control. However, slight modifications were observed in the gills at high concentrations. These results demonstrated that TiO₂ appears to exert little toxicity on marine mussels after a short-term exposure at high concentration. However, before considering the use of this nanomaterial in various applications, further complementary studies are required in order to ensure the environmental safety of these NPs.     

Perception,knowledge and attitude towards environmental issues and management among residents of Al-Suwaiq Wilayat,Sultanate of Oman

The purpose of this study was to determine residents’ perception, knowledge and attitude towards environmental issues and management in the Al-Suwaiq Wilayat (administrative zone) of Al-Batinah North, Sultanate of Oman. For this purpose, a questionnaire was used with questions on issues related to environment and surveyed across 109 households in the Wilayat following a random sampling method in early 2015. The results show that education, health-related infrastructure and unemployment are ranked as most important issues for government attention today and in coming 10 years besides their concern for the environment. Resident’s perceptions on most important environmental issues were concerned about solid-waste pollution, degradation of coastal areas, saltwater intrusion and land degradation. The sources for environmental information, government agencies, local media and schools were regarded as most reliable. Top environmental priorities were suggested to deal with enforcement of regulations, provide effective environmental awareness and education programs. Further, it is suggested that additional studies should be conducted such as ‘State of Environment Reporting’, thereby such reporting, for instance would provide some form of verification of reported behaviour and improved knowledge.