Utilization Of Hazardous Wastes Research Articles

Synthesis of gel crosslinked composite material from spent cathode carbon blocks and its application in modified asphalt binders

The utilization of spent cathode carbon blocks (SCCB) from aluminum electrolysis has become challenging due to their content of highly toxic cyanides and environmentally harmful fluorides. To achieve reliable recovery and utilization of hazardous waste, targeted research has been conducted on the treatment of waste cathode carbon blocks and their potential application in asphalt pavement. Hydrogen peroxide (H2O2) is employed to remove cyanides from the waste cathode carbon blocks, meeting the construction requirements for transportation areas. Anhydrous calcium chloride is used as a calcium source to precipitate soluble fluorides in the solution. Finally, the waste cathode carbon blocks are gel-crosslinked using polyvinyl alcohol-polyvinyl pyrrolidone, addressing the release of fluorides beyond environmental tolerance. This results in the synthesis of a composite material consisting of calcium fluoride deposits and gel-encapsulated waste cathode carbon blocks (PSB), which exhibits good thermal stability in the temperature range of 0–217 °C. Through DSR and MSCR testing, it has been demonstrated that the gel-crosslinked waste cathode carbon block composite material improves the asphalt's sensitivity to temperature and enhances its resistance to rutting at high temperatures. The 1% PSB/SBS modified asphalt shows the best performance, compared to SBS, the complex modulus (G*) of the modified asphalt increased by 117.4% at 46 °C, and the recovery indices for creep at 64 °C improved by 39.28% (at 0.1 kPa) and 55.65% (at 3.2 kPa), and thermal gravimetric analysis of the asphalt confirms that the addition of PSB improves the asphalt's thermal stability. Fluorescence microscopy analysis reveals that the inclusion of PSB does not affect the morphological development of SBS swelling and plays a stabilizing and supporting role in the asphalt mixture.

Electroplating sludge-derived metal and sulfur co-doping catalyst and its application in methanol production by CO2 catalytic hydrogenation

Electroplating sludge is a hazardous waste and its recycling is a hot topic. Electroplating sludge usually contains plenty of transition metals and multi-hetero atoms, which are potential resources. For the first time, this work synthesized spinel catalyst from Zn- and Cr-containing electroplating sludges by a simple calcination method, and applied the obtained catalysts in CH3OH production by CO2 catalytic hydrogenation. The spinel was doped by various heteroatoms, including Fe, Mn, Cu, and even S. According to detailed characterizations, the metal doping increased the low-temperature conversion efficiency of CO2 but decreased the CH3OH selectivity at the same time. After a further doping of S, although CO2 conversion efficiency was slightly decreased, the selectivity of CH3OH was significantly increased. After all, the optimized catalyst attained a conversion efficiency of 8.6% (CO2) as well as a selectivity of 73.3% (CH3OH) at 250 °C and 3 MPa. As a result, above results realized high-value-added utilization of hazardous waste and producing valuable product at the same time, which was in favor of circular development.

Waste cigarette butt-derived B, N doped bifunctional hierarchical mesoporous carbon for supercapacitor and oxygen reduction reaction

Utilization of hazardous waste into valuable materials is the prime need globally. Herein, discarded cigarette filters (a harmful waste/environmental hazard) were utilized to produce heteroatom (Nitrogen and Boron) doped hierarchical mesoporous carbon nanocomposite (NHMC and B-NHMC) via simple elegant hydrothermal route. The fabricated hierarchical mesoporous carbons (HMC), N-doped carbon (NHMC) and boron doped carbon (B-NHMC) composite exhibited high surface area about to 972, 1283 and 1869 m2 g−1 respectively with the mesoporosity (~ 13–16 nm). Scanning electron microscopy confirmed the hierarchical nature of the produced carbon. Elemental analysis (CHN) established the presence of C, H, N, B and O elements. Electrochemical studies showed remarkable super-capacitive behavior in 6 M KOH electrolyte. The specific capacitance of the fabricated electrode materials HMC, NHMC and B-NHMC was observed 309, 325 and 365 F g−1 respectively and was calculated through CV graphs at a potential of 2 mV s−1. Moreover, GCD showed an enhanced specific capacitance of 320, 355 and 373 F g−1 at a current density of 0.5 A g−1 for HMC, NHMC and B-NHMC sample electrodes. The capacitance retention graphs showed high retention of 91%, 93% and 95% after 5000 segments of charge discharge curves of HMC, NHMC and B-NHMC electrodes, which confirmed an excellent capacitance retention exhibited by the materials. An excellent electrocatalytic performance was exhibited by B-NHMC material for oxygen reduction reaction (ORR) with an onset and half wave potential of 0.975, 0.835 V respectively in O2 saturated 0.1 M KOH electrolyte, The value of Tafel slope of B-NHMC catalyst was examined 89.5 mV dec−1, which shows a close agreement with commercial Pt/C (20%) 87.7 mV dec−1, demonstrating good kinetic properties of B-NHMC catalyst, which is near about the commercial Pt/C (20%). The average number of electrons transferred during the ORR process is 3.96, which is found a close resemblance with the ideal four electrons ORR process. Thus, discarded cigarette filters can be smartly utilized as waste to manufacture heteroatom doped (N and B) hierarchical mesoporous carbon (NHMC/B-NHMC) composite at commercial scale to solve the municipality and environmental issue and to utilize in energy storage system and fuel cells.

Ball milling transformed electroplating sludges with different components to spinels for stable electrocatalytic ammonia production under ambient conditions

Electroplating sludge is classified as hazardous waste, but it is also a potential raw resource since it contains plenty of transition metals. However, the component of electroplating sludge is unstable, which hinders recycling. This work investigates the possibility to synthesize spinels with stable catalytic performances by different electroplating sludges. The obtained catalysts are used in electrocatalytic N2 reduction to produce ammonia. As a result, CuCr2O4, ZnCr2O4, and NiCr2O4 spinels are successfully synthesized by a ball-milling and calcination method. These spinels result in ammonia yields of 7.30–8.86 μg h−1 mg−1cat. Among the three spinels, CuCr2O4 shows the highest yield of 8.86 μg h−1 mg−1cat at −0.9 V. Its faradaic efficiency reaches 0.57%. In addition, no by-product N2H4 is detected, indicating a high selectivity. The catalytic process is carried out by both distal and alternating pathways, in which metal doping and oxygen vacancy function as binding sites for N2 adsorption and reduction. Above results indicate that electroplating sludges with unstable components are feasible to produce spinels for stable electrocatalytic ammonia production under ambient temperature. This is in favor of high-value-added utilization of hazardous waste, and devotes to circular economy.

Опасные отходы у населения: проблемы, поиск решений их раздельного накопления

Garbage and various waste products are an integral part of human life, but today they have become a global problem. The main reason why the accumulation of garbage requires special attention and new ways of processing and disposal is the accumulation of hazardous waste generated by the population. The article deals with the problems of waste management of 1st and 2nd hazard classes, the ways of solving these problems are proposed. The main purpose of this article is to determine the authorities responsible for hazardous waste management, review the hierarchy of waste management in case of hazardous waste. As a result, recommendations for establishing a system of separate collection and utilization of hazardous waste are proposed.

Impact of Aggressive Media on the Properties of Polymeric Coatings with Solidification Products as Fillers

Dealing with waste materials, particularly hazardous waste, is a serious problem. Disposal areas keep growing, and the costs incurred are high. Disposing of such waste reduces negative environmental impacts and offers considerable financial savings. This paper focuses on the possibilities of incorporating pollutants found in hazardous wastes as fillers in coatings based on polymers (epoxide and polyurethane). These coatings are intended mainly for concrete and metal bases and offer secondary protection against adverse weather conditions. Important physical and mechanical properties of the newly developed materials were determined; they include surface hardness, impact resistance, tensile properties, and chemical resistance. These properties were also compared to those of the reference filler. At the same time, the influence of aggressive media on the properties of these materials was observed, in particular on flexural characteristics. The microstructures of the developed coatings were tested using a high-resolution optical microscope, before and after exposure to the chemicals. The positive effect of using progressive fillers, such as solidified hazardous waste (a solidification product (SF)), was witnessed by their constructive contribution to the materials’ physical and mechanical properties. The use of solidification products is unambiguously advantageous from technical, ecological, and economical stand points (utilization of hazardous waste as a progressive filler instead of landfilling, improvement of tensile properties, reduction in the price of coating system, and incorporation of the pollutants into the polymer matrix).

The facile synthesis of a nanoscale composite from fly ash and lime stone

Here we report the synthesis of a nanocomposite SiO2/CaCO3 by extraction of SiO2 from fly ash and CaCO3 from limestone via the sol-gel method followed by ultrasonication. The preliminary analysis of SEM has been used to characterize the nanocomposite. Results showed that the synthesized material has a nanoscale structures and a typical similarity of composition compared to quartz, vaterite, and calcite respectively. Size distribution of nanocomposite was better than PCC, a conventional paper filler used in paper industry. The application of nanocomposite as paper filler would promise the better physical properties improvement. In terms of efficiency, the estimation of production cost by using nanocomposite would be lower than the conventional filler such as PCC. The utilization of hazardous waste from coal combustion would be also important to develop a green framework of pulp & paper industry.

当前产业协同处置利用危废技术的进展研究

当前产业协同处置利用危废技术的进展研究

Microbial biotechnology for implementation of the new global program for sustainable development of agrosphere in Ukraine

The objectives needed to implement the new global program for sustainable future are considered. Biotechnologies in the light for solution new problems of the sustainable development are systematized. Modern high-tech biotechnology plays an important role in implementation the strategic objectives formulated in the new global program for sustainable future, including: the environmental aspect, improving the adaptation of natural and modified by anthropogenic pressures ecosystems, biodiversity conservation, improve of food quality by producing the safe and healthy products for functional purpose. The application of environmentally friendly biopreparations makes it possible to increase crop resistance to biotic and abiotic stress, increase productivity and improve the quality of the resulting product, reduce pesticide load on the ecosystem, to achieve bioremediation of contaminated land. Biotechnology for recovery and recycling of resources, utilization of hazardous wastes with renewable energy production favors to sustainable development and expanding of the resource base. Modern biotechnologies should take an important role in environmental protection, agriculture, food industries and renewable energy. The use of microbial biotechnologies is attractive for investors, environmental and economic effective and responsible to vector tasks of «Sustainable Development Strategy «Ukraine-2020»

The partitioning behavior of trace element and its distribution in the surrounding soil of a cement plant integrated utilization of hazardous wastes.

In the present study, the trace elements partitioning behavior during cement manufacture process were systemically investigated as well as their distribution behaviors in the soil surrounding a cement plant using hazardous waste as raw materials. In addition to the experimental analysis, the thermodynamic equilibrium calculations were simultaneously conducted. The results demonstrate that in the industrial-scale cement manufacture process, the trace elements can be classified into three groups according to their releasing behaviors. Hg is recognized as a highly volatile element, which almost totally partitions into the vapor phase. Co, Cu, Mn, V, and Cr are considered to be non-volatile elements, which are largely incorporated into the clinker. Meanwhile, Cd, Ba, As, Ni, Pb, and Zn can be classified into semi-volatile elements, as they are trapped into clinker to various degrees. Furthermore, the trace elements emitted into the flue gas can be adsorbed onto the fine particles, transport and deposit in the soil, and it is clarified here that the soil around the cement plant is moderately polluted by Cd, slightly polluted by As, Cr, Ba, Zn, yet rarely influenced by Co, Mn, Ni, Cu, Hg, and V elements. It was also estimated that the addition of wastes can efficiently reduce the consumption of raw materials and energy. The deciphered results can thus provide important insights for estimating the environmental impacts of the cement plant on its surroundings by utilizing wastes as raw materials.

KONSEP PAKAIAN JOGJA FASHION WEEK CARNIVAL DALAM STRUKTUR SOSIAL DI YOGYAKARTA

The Jogja Fashion Week Carnival (JFWC) is related to various agendas of the local government in Yogyakarta, particularly in industrial and tourism sectors. The JFWC event is correlated to the domestic industries in which one of them has a positive impact upon the progress and the existence of this industry in order to reduce the rate of import from outside Yogyakarta. In another domain, the use of public space, which is often done by JFWC event, gives entertainment and cultural education to the people, thus this event is useful and appropriate if it is held as a routine agenda for the existence of the tourism industry in Yogyakarta. The education given to the people includes the global warming issue, the treatment and utilization of hazardous waste, and the important role of JFWC event in an attempt to create clothing trend centre in Yogyakarta. The dialectics of JFWC clothes can be seen as a process of cultural diplomacy locally, nationally, and internationally. In addition, the existence of JFWC clothes can be viewed as a sustainability phenomenon of contemporary artworks in Indonesia.

Eco‐mapping as a basis for environmental management systems integration at small and medium enterprises

Purpose – The purpose of the paper is to show that environmental management integration to a small Estonian enterprise which main activities are freightage services and vehicles' maintenance and repair works, implementing a visual, simple and practical tool – Eco‐mapping. Design/methodology/approach – The paper shows that Eco‐mapping is a practical, visual and easy‐to‐use toolbox, which gets employees, involved in good environmental practice. It is the first step towards integrating environmental considerations into the day‐to‐day activities of small SMEs. Eco‐mapping is a step‐by‐step process to gather useful information and to immediately trigger environmental action. In total, 80 percent of environmental information is location‐based. There are ten basic steps, which identify environmental aspects, significance of the problems, environmental targets and an action programme of the considered field. Findings – The findings in this paper show the implementation steps of Eco‐mapping tool into the small Estonian company. During the case study all hazardous impacts on human health and environment have been evaluated and the workers awareness was raised. Practical implications – The paper shows that after the overall analysis the company has received clear picture of the problem areas. The most worrying was connected to material storage handling that might had heavy influence to environment as well as to health and safety in particular leakages, risk of explosion, health hazard, emissions. The preventive measures that can be easily taken may decrease these risks in many times. They are the following: fire system integration; electrical system approval; correct utilization of hazardous wastes; and legal issue studying. Originality/value – The paper presents the practical example of implementation of the Eco‐mapping tool in one small Estonian company. This paper gives an overview of the implementation process, describes the main concerns and suggests possible solutions. The project helps managers and other workers to understand that careful relation to the environment might be favorable from an economic point of view, as compliance with regulation and preparing sustainable principles for future generations.