Three-dimensionally ordered macroporous perovskite materials for environmental applications

Three-dimensionally ordered macroporous(3DOM)perovskite materials have attracted the interest from researchers worldwide due to their unique macroporous structure,flexible composition,tailorable physicochemical property,high stability and biocompatibility.In particular,they were widely used in environmental field,such as photocatalysis,catalytic combustion,catalytic oxidation and sensors.In this review,the recent progresses in the synthesis of 3DOM perovskite materials and their environmental applications are summarized.The advantages and the promoting mechanisms of 3DOM perovskite materials for different applications are discussed in detail.Subsequently,the challenges and perspectives on the topic are proposed.

Changes in Organic Carbon and Nutrient Contents of Highly Productive Paddy Soils in Yujiang County of Jiangxi Province,China and Their Environmental Application

Paddy field is an important land use in subtropical China. Development of high soil fertility and productivity is the management goal of paddy field, Fertilization and management practices have not only influenced the status of organic matter and nutrients in the soil but also affected the environmental quality. This article investigates the contents of organic carbon and the nutrients, and the change over the last 20 years in highly productive paddy soils and their environmental application. Field soils were sampled and the analytical results were compared with the corresponding values in the Second Soil Survey in Yujiang County of Jiangxi Province, China. The results showed that surface soils at a depth of 0-10 cm in highly productive paddy fields in Yujiang County of Jiangxi Province had contents of organic carbon （20.2 ±3.88） g kg^-1, total nitrogen （2.09±0.55） g kg^-1, and available phosphorus （42.7 ±32.7） mg kg^-1, respectively, which were all at very rich levels. Over the last 20 years, the organic carbon pool of the highly productive paddy soils reached a steady state. Total N and available P significantly increased, whereas available K changed a little. The amount and percentage of P immobilization in the surface soil （0-10 cm） of highly productive paddy fields were （142.7 ~ 41.1） mg kg-~ and （36.2~ 10.4）% of added P, and CEC （7.93 ~ 1.32） cmol kg-~. These two parameters were not higher than the mean values of paddy soils and upland red soils in the areas. Results also showed that fertilizer P in highly productive paddy soils had a high mobility and was prone to move toward a water body, which is the main source of nutrients causing eutrophication. Because of a weak K-fixing capacity, the available K content was not high in highly productive paddy soils. This suggests that attention should be paid to the K balance and the increase of soil K pool.

Catalytic degradation of methylene blue by Fenton like system: model to the environmental reaction

To develop more efficient chemical methods for the demineralization of organic pollutants from water bodies, which one was also mimic to the nature, a degradation of methylene blue by Fe(Ⅲ) and H 2O 2 in the absence of light instead of Fe(Ⅱ) and H 2O 2 was studied. Results showed that use of Fe (Ⅲ) is more promising than Fe(Ⅱ). The present study reflects that Fenton reaction is more efficient, in the presence of a small amount of salicylic acid is added which is a one of the priority pollutant.

APPLICATIONS OF REMOTE SENSING IN ENVIRONMENTAL INVESTIGATION AND CHANGE ANALYSIS IN THE THREE GORGES AREA

1. INTRODUCTION The proposed Three Gorges Project, one of the biggest hydroelectric projects in the world, will dam the middle reaches of the Changjiang (Yangtze) River, the third longest river in the world, and form a large reservoir. Its impacts on environment have attracted wide attention. Entrusted by National Scientific-Technical Commission, the Chinese Academy of Sciences (CAS) was in charge of a research project on this issuse from 1984 to 1989. Tho use of remote sensing played an important role in the project considering the study area is mountainous and not convenientlv located, which makes it difficult to conduct the research onlv using conventional means.

Advanced semiconductor catalyst designs for the photocatalytic reduction of CO_(2)

Using clean solar energy to reduce CO_(2)into value-added products not only consumes the over-emitted CO_(2)that causes environmental problems,but also generates fuel chemicals to alleviate energy crises.The photocatalytic CO_(2)reduction reaction(PCO_(2)RR)relies on the semiconductor photocatalysts that suffer from high recombination rate of the photo-generated carriers,low light harvesting capability,and low stability.This review explores the recent discoveries on the novel semiconductors for PCO_(2)RR,focusing on the rational catalyst design strategies(such as surface engineering,band engineering,hierarchical structure construction,single-atom catalysts,and biohybrid catalysts)that promote the catalytic performance of semiconductor catalysts on PCO_(2)RR.The advanced characterization techniques that contribute to understanding the intrinsic properties of the photocatalysts are also discussed.Lastly,the perspectives on future challenges and possible solutions for PCO_(2)RR are presented.

Layered photocatalytic nanomaterials for environmental applications

The increasing pollution and human demand for a cleaner environment have made achieving the environmental sustainability a current research focus.As a “green” technology,semiconductor photocatalysis is of great significance to the environmental purification.Benefiting from the unique anisotropic crystal structure and electronic properties,layered photocatalytic nanomaterials show great potential for efficient photocatalytic environmental treatment.This review comprehensively summarizes the recent progress on layered photocatalytic nanomaterials for oxidation or reduction of pollutants in water and air along with the basic understanding of related mechanisms and developments in this field.First,the existing diversified layered photocatalysts are classified,and their different synthesis and modification strategies are discussed in detail to provide a comprehensive view of the material design that affects their photocatalytic performance.Subsequently,the extensive applications of the above-mentioned layered photocatalytic nanomaterials in environmental fields are systematically summarized,including photooxidation of water and air pollutants,and photoreduction of heavy metal pollutants,NO_(3)^(-),BrO_(3)^(-) and CO_(2).Finally,based on the current research achievements in layered photocatalysts for environmental remediation,the future development direction and challenges are proposed.

Students’Feedback on Integrating Engineering Practice Cases into Lecture Task in Course of Built Environment

The improvement of students’abilities is of great significance to discover the relevant scientific problems in daily life,to analyze and solve practical problems,to trigger scientific inspiration,and to encourage innovation and entrepreneurship.Taken the course entitled Built Environment(BE)as an example,this study introduces five lecture cases combining with engineering practices,and examines the evaluation of teaching and learning effect on student outcomes.The cases consider various problems to be solved urgently in an actual project,and evaluate the student outcomes by statistically analyzing the questionnaires.Most of the students actively participate in five cases and cheerfully share their achievements.More than 85%of students are satisfied with the engineering practice and the learning proposal,and convey a little or even significantly change in their understanding of the employment prospects.

Advances in inorganic nanoparticles trapping stiffness measurement:A promising tool for energy and environmental study

Optical tweezers system has emerged as an efficient tool to manipulate tiny particles in a non-invasive way.Trapping stiffness,as an essential parameter of an optical potential well,represents the trapping stability.Additionally,trapping inorganic nanoparticles such as metallic nanoparticles or other functionalized inorganic nanoparticles is important due to their properties of good stability,high conductivity,tolerable toxicity,etc.,which makes it an ideal detection strategy for bio-sensing,force calculation,and determination of particle and environmental properties.However,the trapping stiffness measurement(TSM)methods of inorganic nanoparticles have rarely been analyzed and summarized.Here,in this review,the principle and methods of TSM are analyzed.We also systematically summarize the progress in acquiring inorganic particles trapping stiffness and its promising applications.In addition,we provide prospects of the energy and environment applications of optical tweezering technique and TSM.Finally,the challenges and future directions of achieving the nanoparticles trapping stiffness are discussed.

Green Offshore Structures Promising Viable Utilization of Shipyard Facilities

The shipbuilding industry in Europe is in crisis due to the recent economic recession and competition from countries with low labour costs. Greek shipyards have been forced to make a series of structural changes which have resulted in lower employment levels. Although these changes were gradually creating the conditions for shipyards profitably to re-enter international markets, the current economic crisis and the consequences to the shipping sector have created major problems to the shipyards employment. Perama shiprepair zone, an industrial zone mainly consisted from SMEs （small and medium enterprises） in shipbuilding and shiprepairing sector, has faced major problem for its survivability. In this article, a new approach is presented. Green offshore structures are expected to create competitive advantages in the zone and be a way to utilize available facilities and recover from the existing situation. International experience through case studies is presented followed by economic and technical feasibility for offshore windturbines construction and wave energy devices in shipyards. Finally, a general model shows that sustainable development is possible and shipyards have the adaptability and resources required tbr the production of renewable energy offshore structures.

Preparation and characterization of M_(1)-N_(x)-C_(y)based single atom catalysts for environmental applications

Single atom catalysts(SACs)have become the frontier research fields in catalysis.The M_(1)-N_(x)-C_(y)based SACs,wherein single metal atoms(M1)are stabilized by N-doped carbonaceous materials,have provided new opportunities for catalysis due to their high reactivity,maximized atomic utilization,and high selectivity.In this review,the fabrication methods of M_(1)-N_(x)-C_(y)based SACs via support anchoring strategy and coordination design strategy are summarized to help the readers understand the interaction mechanism of single atoms and support.Then,characterization technologies for identifying single metal atoms are presented.Besides,the environmental applications including management of harmful gases,water purification are discussed.Finally,future opportunities and challenges for preparation strategies,mechanisms and applications are concluded.We conclude this review by emphasizing the fact that M_(1)-N_(x)-C_(y)based SACs has the potential to become an important candidate for solving current and future environmental pollution problems.

Research progress on synthesis of zeolites from coal fly ash and environmental applications

The by-product of coal combustion,coal fly ash(CFA),has become one of the world’s most emitted solid wastes,and bulk utilization while achieving high value-added products is the focus of current research.Using CFA to prepare zeolite cannot only reduce environmental pressure,but also obtain high value-added products,which has a good market prospect.In this paper,the research progress of hydrothermal synthesis method of CFA zeolites is reviewed in detail and summarized several other synthetic methods of CFA zeolites.This review also presents an overview of CFA zeolites application in environmental applications like water treatment,gas adsorption and soil remediation.However,a considerable number of literature data have documented using CFA zeolites for water treatment,whereas research on CFA zeolites application to gas adsorption and soil remediation is still limited.In addition,the current status of basic research on the industrial production of CFA zeolites is briefly summarized,and the development trend of the synthetic zeolite of CFA is prospected.After the feasibility analysis of the industrial production of CFA zeolite,it is concluded that the only two methods with high feasibility for industrial application are two-step hydrothermal and alkali melting methods,and the industrial production technology still needs to be studied in depth.

The Preparation and Application of Chitosan Compound Flocculant

[Objective]The research aimed to study preparation and application of the environment-friendly compound flocculant.[Method]Chitosan（natural biological product,CTS）,ferric sulfate[Fe2（SO4） 3]and polymeric aluminum chloride（PAC） as the main raw materials,four kinds of environment-friendly flocculants were made to conduct flocculation treatment on the domestic wastewater of Wuhan Bioengineering Institute.COD and turbidity of the wastewater as the main indicators,influences of the compound flocculant formulation,flocculant dosage and pH on flocculation effect were studied.[Result]CTS/PAC and CTS/Fe2（SO4） 3 compound flocculants had better removal rates for COD and turbidity when compared with single inorganic flocculant.The best volume ratio of CTS/PAC was 1.0：5.0.The smallest dosage of CTS/PAC in each 500 ml of water sample was 4.0 ml.When pH was 7.2,removal rates of the COD and turbidity were respectively 78.5% and 98.4%,which rose by 36.5% and 21.5% respectively than that singly using PAC.[Conclusion]CTS/PAC was a kind of ideal compound flocculant and had better application prospect.

APPLICATION OF REMOTE SENSING IN THE ANALYSIS OF WATER ENVIRONMENT IN ZHUJIANG RIVER ESTUARY

1. PREFACE Lingdingyang is a trumpet estuary. It accepts the runoff of the Dongjiang River, the Beijiang River, the Zhengjiang River and the Liusihe River. It also accepts a part of the runoff of the Xijiang River. Its mean year runoff is 1.742×10" M^3. In resent ten years, industry and agriculture are developing rapidly in Guangzhou City, Dongguan City, Zhongshan City, Shunde County, Panyu County. Lingdingyang’s pollution is increesing. Water quality of lingdingyang is steadily deteriorated. In order to investigate the situation of water environment of Lingdingyang, we study its static environmental capacity of nitrogen and phosphorus. LANDSAT imageries are used in the study. The concentrations of nitrogen and phosphorous is detected by convention method.

Review of the progress in preparing nano TiO_2: An important environmental engineering material

TiO2 nanomaterial is promising with its high potential and outstanding performance in photocatalytic environmental applications, such as CO2 conversion, water treatment, and air quality control. For many of these applications, the particle size, crystal structure and phase, porosity, and surface area influence the activity of TiO2 dramatically. TiO2 nanomaterials with special structures and morphologies, such as nanospheres, nanowires, nanotubes, nanorods, and nanoflowers are thus synthesized due to their desired characteristics. With an emphasis on the different morphologies of TiO2 and the influence factors in the synthesis, this review summarizes fourteen TiO2 preparation methods, such as the sol-gel method, solvothermal method, and reverse micelle method. The TiO2 formation mechanisms, the advantages and disadvantages of the preparation methods, and the photocatalytic environmental application examples are proposed as well.

Current molecular biologic techniques for characterizing environmental microbial community

Microbes are vital to the earth because of their enormous numbers and instinct function maintaining the natural balance. Since the microbiology was applied in environmental science and engineering more than a century ago, researchers desire for more and more information concerning the microbial spatio-temporal variations in almost every fields from contaminated soil to wastewater treatment plant （WWTP）. For the past 30 years, molecular biologic techniques explored for environ- mental microbial community （EMC） have spanned a broad range of approaches to facilitate the researches with the assistance of computer science： faster, more accurate and more sensitive. In this feature article, we outlined several current and emerging molecular biologic techniques applied in detection of EMC, and presented and assessed in detail the application of three promising tools.

Ten years of microalgal biofuels in environmental applications

Over the past ten years,microalgae have been investigated as promising sources of renewable energy to replace the diminishing supply of fossil fuels and mitigate the environmental pollution caused by use of fossil fuels.In addition to providing oil-based biofuels,the use of microalgae can potentially reduce environmental pollution because algae can use industrial byproducts(CO_2,NOx,wastewater,and others)as nutrition sources.However,our previous study showed that the unacceptably high cost of biofuels production,especially culturing microalgae,remains the biggest obstacle hindering the large-scale implementation of microalgae biofuels.Therefore,future efforts will likely emphasize biotechnological approaches to improve the economic feasibility of algal biofuel production.This review summarizes the progress made over the last decade in environmental applications of microalgae,combined with data on CO_2 capture,NOx biotransformation,wastewater treatment,and synergistic applications,and discusses future prospects.

Application of a DPC for PMD Compensation in Environmental Perturbed Transmission System

Polarization mode dispersion (PMD) compensation is presented on environmental perturbed fiber-optical transmission system in this paper. We achieve a dynamic polarization controller (DPC) to feedback control the PMD, successfully.

CeO_(2)and CeO_(2)-based nanomaterials for photocatalytic,antioxidant and antimicrobial activities

Cerium oxide(CeO_(2)),one of the most significant rare-earth oxides,has attracted considerable interest over the past decades.This is primarily due to the ease in Ce^(3+)/Ce^(4+)redox ability as well as other factors that affect the efficacy of CeO_(2)and CeO_(2)-based materials.CeO_(2)and CeO_(2)-based materials have shown enhanced responses in catalytic and photocatalytic activities for environmental and biological applications.In addition,the formation of Ce^(3+)and oxygen vacancies in CeO_(2)has aided in enhancing CeO_(2)activities.In order to produce oxygen-deficient CeO_(2)and CeO_(2)-based materials,a variety of synthesis methods were used and are highlighted in this review.Therefore,this review compiles and discusses the mechanisms that involve oxygen vacancies,defects,and Ce^(3+)formation for environmental applications,such as photocatalytic dye degradation,photocatalytic CO_(2)reduction,and non-colored pollutants removal.The biological applications of CeO_(2),such as antioxidant enzyme mimetic,antioxidant reactive oxygen species/reactive nitrogen species,and antimicrobial activities,are also discussed.Additionally,future prospects are also suggested for future development and detailed investigations.

Microalgae-based wastewater treatment:Mechanisms,challenges,recent advances,and future prospects

The rapid expansion of both the global economy and the human population has led to a shortage of water resources suitable for direct human consumption.As a result,water remediation will inexorably become the primary focus on a global scale.Microalgae can be grown in various types of wastewaters(WW).They have a high potential to remove contaminants from the effluents of industries and urban areas.This review focuses on recent advances on WW remediation through microalgae cultivation.Attention has already been paid to microalgae-based wastewater treatment(WWT)due to its low energy requirements,the strong ability of microalgae to thrive under diverse environmental conditions,and the potential to transform WW nutrients into high-value compounds.It turned out that microalgae-based WWT is an economical and sustainable solution.Moreover,different types of toxins are removed by microalgae through biosorption,bioaccumulation,and biodegradation processes.Examples are toxins from agricultural runoffs and textile and pharmaceutical industrial effluents.Microalgae have the potential to mitigate carbon dioxide and make use of the micronutrients that are present in the effluents.This review paper highlights the application of microalgae in WW remediation and the remediation of diverse types of pollutants commonly present in WW through different mechanisms,simultaneous resource recovery,and efficient microalgae-based co-culturing systems along with bottlenecks and prospects.