Due to its persistence and potential negative effects on ecosystems and human health, microplastic pollution in aquatic environments has become a major worldwide concern. Photocatalytic degradation is a sustainable manner to degrade microplastics to non-toxic by-products. In this review, comprehensive discussion focuses on the synergistic effects of various photocatalytic materials including TiO₂, ZnO, WO₃, graphene oxide, and metal–organic frameworks for producing heterojunctions and involving multidimensional nanostructures. Such mechanisms can include the generation of reactive oxygen species and polymer chain scission, which can lead to microplastic breakdown and mineralization. The advancements of material modifications in the (nano)structure of photocatalysts, doping, and heterojunction formation methods to promote UV and visible light-driven photocatalytic activity is discussed in this paper. Reactor designs, operational parameters, and scalability for practical applications are also reviewed. Photocatalytic systems have shown a lot of development but are hampered by shortcomings which include a lack of complete mineralization and production of intermediary secondary products; variability in performance due to the fluctuation in the intensity of solar light, limited UV light, and environmental conditions such as weather and the diurnal cycle. Future research involving multifunctional, environmentally benign photocatalytic techniques—e.g., doped composites or composite-based catalysts that involve adsorption, photocatalysis, and magnetic retrieval—are proposed to focus on the mechanism of utilizing light effectively and the environmental safety, which are necessary for successful operational and industrial-scale remediation.

Slow sand filtration (SSF) is one of the traditional methods of water treatment yet gaining attention as a promising method. The rising demand is owing to its simplicity, environmental friendliness and effectiveness, which can reach 90-95%. This chapter reviews the principles and mechanisms underlying SSF, particularly addressing the physical, biological, and chemical processes that contribute to its effectiveness. Furthermore, the chapter delves into the design and construction of SSF systems, with a particular emphasis on the critical components and factors that facilitate the attainment of optimal performance. The efficacy of the method in enhancing water quality is assessed through a variety of analytical methods, including the removal of turbidity, the reduction of pathogens, and the removal of organic matter. The chapter also encompasses the environmental impact assessment of SSF to guarantee its long-term sustainability.

The need to extend food products' shelf lives is growing as a result of efforts to cut expenses and minimize food waste. The food industry is interested in solutions that would make it easy to keep food fresh and safe for as long as the product is on sale. The purpose of the study is to develop a biopolymer-based colorimetric indicator for monitoring of meat and fish freshness. The significance of the research is to provide food safety via control of the freshness using green and cheap methods. The objects of the study are natural and artificial indicators. The paper presents natural indicators such as curcumin, pomegranate, beetroots, and carrot juice which were incorporated into the compositions of food freshness indicators. The obtained indicators were compared with an artificial indicator, bromothymol blue, and phenol red, concerning their volatile amine monitoring. Additionally, a model of volatile amine release based on the different ammonia solutions was applied in the research. The response of freshness indicators was estimated by the observation of color changes. Compared to the artificial indicators, the curcumin and pomegranate juices gave a similar response. Beetroot and carrot juices did not provide a desirable color change. Further research was made on the development of biopolymer containing freshness indicators based on bromothymol blue and phenol red. The indicators were evaluated for their response to the spoilage of fish and meat samples in the test tubes and in food packaging. Thus, two artificial indicators could be incorporated into effective food freshness indicators for smart packaging.

Горно-металлургическая промышленность является значительным источником разнообразных отходов, которые требуют утилизации или повторного использования. В последние годы возрос интерес к разработке технологий и процессов, направленных на использование этих отходов для получения новых материалов, что имеет важное значение для снижения нагрузки на окружающую среду и оптимизации ресурса потребления. В данной работе рассматриваются основные методы и технологии получения материалов из горно-металлургических отходов, их преимущества и перспективы применения. В работе представлен обзор наиболее эффективных технологий по извлечению различных видов сырья и готовой продукции из горно-металлургической промышленности. Показаны разработанные технологии извлечения ценных компонентов из отходов производства на основании проведенных лабораторных исследований. В данной работе были получены наночастицы диоксида кремния, геополимерный материал, материал, содержащий фазовый электропроводящий состав Тау-кен металлургия өнеркәсібі кәдеге жаратуды немесе қайта пайдалануды қажет ететін әртүрлі қалдықтардың маңызды көзі болып табылады. Соңғы жылдары осы қалдықтарды жаңа материалдар алу үшін пайдалануға бағытталған технологиялар мен процестерді дамытуға қызығушылық артты, бұл қоршаған ортаға түсетін зиянды азайту және ресурстарды тұтынуды оңтайландыру үшін маңызды. Бұл жұмыста тау-кен және металлургиялық қалдықтарынан материалдарды алудың негізгі әдістері мен технологиялары, олардың артықшылықтары мен қолдану перспективалары қарастырылады. Жұмыста тау-кен металлургия өнеркәсібінен шикізат пен дайын өнімдердің әртүрлі түрлерін алудың ең тиімді технологиялары қарастырылған. Өндіріс қалдықтарынан бағалы компоненттерді алудың әзірленген технологиялары зертханалық зерттеулер негізінде көрсетілген. Жұмыста сирек кездесетін металл кенінің қалдықтарынан кремний диоксиді бар материал, геополимерлі материал, құрамында электрөткізгіштік фазасы бар материал алынды The mining and metallurgical industry is a significant source of a variety of waste that requires disposal or reuse. In recent years, there has been increased interest in the development of technologies and processes aimed at using these wastes to produce new materials, which is important for reducing the burden on the environment and optimizing resource consumption. This paper discusses the main methods and technologies for obtaining materials from mining and metallurgical waste, their advantages and prospects for application. The paper provides an overview of the most effective technologies for the extraction of various types of raw materials and finished products from the mining and metallurgical industry. The developed technologies for extracting valuable components from production waste are shown based on laboratory studies. In this work, the following materials were obtained: silicon dioxide nanoparticles, geopolymer material, material containing a phase conductive composition

This work investigates the synthesis and application of activated carbon derived from rice husk (RH) as a sustainable anode material for lithium-ion batteries (LIBs). The RH precursor underwent a sequence of pretreatment steps including washing, drying, pyrolysis at 500 ℃ in argon atmosphere, chemical activation with KOH at 850 ℃ , and subsequent desilication. The resulting material exhibited a well-developed micro/mesoporous structure with a high specific surface area (>900 m²/g) and structural stability. Morphological analysis confirmed a uniform porous carbon matrix, while XRD revealed the formation of amorphous carbon. Electrochemical performance tests showed that the RH-derived carbon retained a reversible capacity of ~280–300 mAh/g over 50 charge–discharge cycles, indicating excellent cyclic stability and lithium-ion intercalation capability. Cyclic voltammetry and galvanostatic tests demonstrated predominant pseudocapacitive behavior, associated with surface functionalities and structural defects induced by KOH activation. Compared to conventional graphite (372 mAh/g), this bio-derived carbon offers competitive capacity with lower cost and better sustainability. The study highlights the potential of RH-based activated carbon as a scalable and eco-friendly alternative for next-generation energy storage devices, particularly in LIBs and supercapacitors. Future work will focus on optimizing activation parameters and exploring heteroatom doping to further enhance conductivity and rate performance.