Hydrogel photocatalysts for efficient energy conversion and environmental treatment

Photocatalysts have attracted great research interest owing to their excellent properties and potential for simultaneously addressing challenges related to energy needs and environmental pollution.Photocatalytic particles need to be in contact with their respective media to exhibit efficient photocatalytic performances.However,it is difficult to separate nanometer-sized photocatalytic materials from reaction media later,which may lead to secondary pollution and a poor recycling performance.Hydrogel photocatalysts with a three-dimensional(3D)network structures are promising support materials for photocatalysts based on features such as high specific surface areas and adsorption capacities and good environmental compatibility.In this review,hydrogel photocatalysts are classified into two different categories depending on their elemental composition and recent progresses in the methods for preparing hydrogel photocatalysts are summarized.Moreover,current applications of hydrogel photocatalysts in energy conversion and environmental remediation are reviewed.Furthermore,a comprehensive outlook and highlight future challenges in the development of hydrogel photocatalysts are presented.

The Transformation of Environmental Governance from the Point of the Interaction between Government and National People's Congress

Taking cadmium pollution in X River as an example, the interaction between National People＇s Congress and local government was de- scribed. How the local government transforms its role in environment protection with the help of several deputies to National People＇s Congress was expounded from the angle of social construction, which also enlightened the way to build an environment protection road with Chinese characteristics.

Synthesis of Activated Carbon from Polyethylene Terephthalate(PET)Plastic Waste and Its Application for Removal of Organic Dyes from Water

Synthetic plastics are often considered to be materials that cannot be broken down by natural processes.One such plastic,polyethylene terephthalate(PET),is commonly used in everyday items but when these products are discarded,they can cause serious harm to the environment and human health.In this study,PET plastic waste was used to create activated carbon using a physical activation process that involved using CO2 gas.The researchers investigated the effects of different temperatures,carbonization,and activation times on the resulting activated carbon’s surface area.The activated carbon was then analyzed using scanning electron microscopy(SEM),X-ray diffraction(XRD),FTIR,and BET.The activated carbon created from PET plastic waste showed excellent absorption properties for methylene blue in aqueous solutions across a wide range of pH levels.By creating activated carbon from plastic waste,not only are environmental issues addressed,but high-value activated carbon is produced for environmental remediation purposes.

Effect of TiO2 Nanoparticles on Biodegradability of Polystyrene/Starch Blends

A study of biodegradation behavior of Polystyrene/Starch/TiO2 nanocomposites based on evaluating the weight loss of the tested films after water immersion, a-amylase enzymatic solution immersion and soil burial and the tensile properties of the tested fdms. Blend films and the nanocomposites were prepared by hand layup methodwith different weight percentage ratios of TiO2 nanoparticles. The results show that the weight loss of the tested films due towater immersion, enzymatic solution immersion and soil burial decreased with the increasing of TiO2 nanoparticles content but the mechanical properties were enhanced by the addition of TiO2 nanoparticles.

Public Participation in Water Environment Control：the Status and Experience of Shenzhen, Southern China

Public participation is an important part of watershed water environment management. Via public participation, it could enhance public environmental awareness, mobilize multiple forces to reconcile the conflicts among multiple interest groups, supervise corporate environmental be-havior, and overcome the shortcomings of government unilateral decision-making. In this paper, the status quo of public participating in water envi-ronment control is summarized, and the existing problems of public participating in water environment control are analyzed. From the aspects of per-fecting legal system, perfecting water environment information disclosure system, expanding information communication channels, correctly guiding the development of environmental social organization, playing the supervision role of the people＇s congress and political consultative committee, and enriching the forms of publicity and education, the countermeasures and suggestions of public participating in water environment control are proposed, to perfect public participation mechanism, and scientifically and orderly impel comprehensive treatment of water environment.

Carbon quantum dots-based semiconductor preparation methods,applications and mechanisms in environmental contamination

Photocatalyst is the most widespread method in advanced oxidation technologies,but due to the photoinduced electron combine easily with hole and the wavele ngth of adsorption is limited which will affect some practical applications.Carbon quantum dots(CQDs)is non-toxic and harmless green materials,it has the ability to improve the photocatalytic effect which is attributed to its good electrical and optical properties.Their up-conversion effect,photosensitization and electrical conductivity are assistants which help promote the photocatalytic effect in environmental applications.The key mechanisms of CQDs to improve photocatalysis can be roughly divided into three categories:1)Up-conversion effect conve rts the incident light into the emitted light with high ene rgy to solve the problem which is the light absorption range;2)CQDs act as a photosensitizer instead of valence band to provide electrons to the conduction band of semiconductor;3)CQD s can be used as the internal or external electronic conductor in materials to alleviate the trend of electron and hole separation.However,CQDs and CQDs-based photocatalysts have different views to solve environmental problems,so it is necessary to integrate different views.Therefore,this review is mainly aimed at the recent researches about the preparation processes of CQD,CQD s-based photocatalysts,and their ability to remove environmental pollutants,with a special emphasis on the mechanism for depredating pollutants.Furthermore,this paper analyzes and discusses the prospects and challenges of CQDs in the environmental field.

Removing ammonium from water and wastewater using cost-effective adsorbents:A review

Ammonium is an important nutrient in primary production; however, high ammonium loads can cause eutrophication of natural waterways, contributing to undesirable changes in water quality and ecosystem structure. While ammonium pollution comes from diffuse agricultural sources, making control difficult, industrial or municipal point sources such as wastewater treatment plants also contribute significantly to overall ammonium pollution.These latter sources can be targeted more readily to control ammonium release into water systems. To assist policy makers and researchers in understanding the diversity of treatment options and the best option for their circumstance, this paper produces a comprehensive review of existing treatment options for ammonium removal with a particular focus on those technologies which offer the highest rates of removal and cost-effectiveness. Ion exchange and adsorption material methods are simple to apply, cost-effective, environmentally friendly technologies which are quite efficient at removing ammonium from treated water. The review presents a list of adsorbents from the literature, their adsorption capacities and other parameters needed for ammonium removal. Further, the preparation of adsorbents with high ammonium removal capacities and new adsorbents is discussed in the context of their relative cost, removal efficiencies, and limitations. Efficient, cost-effective, and environmental friendly adsorbents for the removal of ammonium on a large scale for commercial or water treatment plants are provided. In addition, future perspectives on removing ammonium using adsorbents are presented.