본 연구는 학교운동장 굴취 토양(WSSPG)을 모래와 혼합 후 토양개량효과를 조사하여 잔디재배토양으로서 적합성을 조사 함으로써 천연잔디 운동장 조성 시 활용가능성을 평가하기 위해 수행되었다. 처리구는 대조구(모래 100%), WSSPG 5% 처리구 (WSSPG 5% + 모래 95%), WSSPG 10% 처리구(WSSPG 10% + 모래 90%), WSSPG 15% 처리구(WSSPG 15% + 모래 85%), WSSPG 20% 처리구(WSSPG 20% + 모래 80%), WSSPG 30% 처리구(WSSPG 30% + 모래 70%), WSSPG 40% 처리구 (WSSPG 40% + 모래 60%)로 설정하였다. WSSPG 처리 후 pH, EC, CEC등은 증대되었고, 모세관 공극, 비모세관 공극, 총공극 및 포화수리전도도는 감소하였다. WSSPG의 처리량과 토양인자간 조사에서 pH, EC, CEC 및 용적밀도는 정의 상관성 을 나타냈고, 모세관 공극, 비모세관 공극, 총공극 및 포화수리 전도도는 부의 상관성을 나타냈다. 상기 결과를 종합할 때, WSSPG는 토양 화학성을 개선하나 물리성 개선은 미미하였고, WSSPG 처리 후 토양의 물리화학성을 고려할 때, WSSPG의 최대 처리량은 약 5% 정도로 판단되었다.

The global e-waste problem is becoming increasingly serious. China, as one of the largest producers and consumers of electronic products, still has a low formal recycling rate. Consumers, as the owners of waste electronics, are the key to successful reverse logistics. However, many choose to store or dispose of e-waste at home rather than use official recycling channels. While many previous studies focus on factors that encourage recycling, fewer examine what stops people from taking part. This study applies Valence Theory to identify the factors that increase consumers’ psychological resistance to recycling small e-waste in China’s first-tier cities. It also examines how these factors influence social value and resistance behavior. The research model includes perceived price unfairness, perceived inconvenience, perceived benefits, and information publicity, with social value as a mediator. Data were collected through an online survey of 303 residents in Beijing, Shanghai, Guangzhou, and Shenzhen. Structural equation modeling (SEM) was used for analysis. The results show that perceived inconvenience and perceived benefits significantly influence social value. Perceived price unfairness, perceived inconvenience, and social value significantly affect consumer resistance. These findings expand the application of Valence Theory in e-waste research and address gaps in the Theory of Planned Behavior by considering both perceived risks and benefits. Practically, this study suggests that manufacturers, recyclers, and policymakers should improve recycling facilities, make the process more convenient, ensure fair and transparent pricing, and create targeted measures to reduce consumer resistance and encourage participation in formal recycling systems.

This study analyzed the emission characteristics of major air pollutants from 97 domestic municipal solid waste incineration facilities using tele-monitoring system (TMS) data collected from 2015 to 2023. Focusing on the effects of the enforcement of enhanced national emission standards in 2019, this research examined changes in emission factors (EFs) of dust and nitrogen oxides (NOX) by facility capacity and aging level. The results showed that the average EFs for dust and NOX significantly decreased by up to 30% after enforcement (p<0.01~0.001), indicating the practical effectiveness of the strengthened standard. This trend was observed consistently across all facility sizes and aging levels, including large-scale and older facilities. In contrast, hydrogen chloride (HCl) and carbon monoxide (CO) did not show clear reductions and remained highly variable, suggesting that emission standards alone may not be sufficient for stable control. These findings demonstrate the need for optimized combustion conditions and improved post-treatment systems for pollutants such as HCl and CO. This study provides empirical evidence highlighting the importance of appropriate facility scale and systematic refurbishment cycles for stable emission reduction in municipal waste incinerators.

In order to optimize the manufacturing of polypropylene-derived few-layer graphene, an innovative utilization of nonsupported iron oxide nanoparticles generated under various fuel environment conditions was studied. Three distinct fuel combustion environment circumstances (fusion, fuel shortage, and fuel excess) produced a variety of Fe2O3 nanoparticles for cost-effective and green graphene deposition. XRD, H2- TPR, Raman, and TGA measurements were used to characterize both new and spent catalysts. Remarkably, the microstructure of the generated Fe2O3 nanoparticles could be controlled by the citric acid/iron nitrate ratio, ranging from spheroids ( Fe2O3(0)) to sheets ( Fe2O3(0.5-0.75)) and a hybrid microstructure that consists of sheets, spheroids, and interconnected strips ( Fe2O3(1-2)). According to fuel situation (citric acid/iron nitrate ratio, Fe2O3( 0-2)), various graphitization level and yields of graphene derivatives including sheets, ribbons, and onions have been developed. With the ideal fuel/oxidant ratio (ɸ = 1), the Fe2O3( 0.75) catalyst demonstrated the best catalytic activity to deposit the largest yield of highly graphitized few graphene layers (280%). Lean and rich fuel conditions (1 > ɸ > 1) have detrimental effects on the amount and quality of graphene deposition. It is interesting to note that in addition to graphene sheets, an excess of citric acid caused the production of metallic cores, hollow, and merged carbon nano-onions, and graphene nano-ribbons. It was suggested that carbon nano-onions be converted into graphene nano-ribbons and semi-onion shell-like graphene layers.

Polypropylene waste significantly contributes to environmental pollution due to its low biodegradability. Numerous experiments have shown that laser irradiation of polymers can lead to the conversion of laser-induced graphene (LIG). In this paper, the LIG formation process in polypropylene (PP), polydimethylsiloxane (PDMS), and polypropylene/polydimethylsiloxane (PP/PDMS) systems in a vacuum environment was simulated using molecular dynamics. The LIG yields and carbon network sizes of the systems in oxygen and vacuum environments at different temperatures were analyzed to determine the optimal temperature for upgrading PP to LIG. It was observed in all three systems that the LIG structure was formed. The structure was composed not only of six-membered carbon rings, but also of five-membered and seven-membered rings, resulting in out-of-plane fluctuations and bending. A vacuum environment and high temperature promote LIG formation with high yield, large size, and minimal defects. The current study provides theoretical guidance for optimizing the laser graphene process for PP assisted with PDMS in a vacuum environment and helps to understand the mechanism underlying the conversion from polyolefins to graphene under CO2 laser at the atomic level.

The purpose of this study is to fabricate a multi-stage, variable-section and high-speed of the cutting device for recycling carbon fiber from waste hydrogen storage tanks. In this study, a high precision cutting device is fabricated utilizes (i.e., multi-stage, variable-section, high-speed cutting function and a diamond wire tool) to cut various waste hydrogen storage tank carbon fibers into scrap in a short period of time. The fabricated items include the development of diamond wire tools and wheels, cutting feed systems, structural frames, cooling system applications, and hydrogen tank fixing systems. The rotational speed of multi-stage wheel is in range of 0~600 rpm, and feed speed of diamond wire cutting tools is in range of 10–80 mm/min. The results showed that a new precision cutting device is able to cut the waste hydrogen storage tanks more than 400 pieces of performance indicator scrap (200×200 mm) within 8 hours of the cutting time. This confirmed that a new fabricated cutting device is a high speed cutting machine that is feasible for application in waste hydrogen storage tanks recycling in stead of conventional cutting device.

Waste utilization is not only a way to protect the environment and realize green chemistry, but also a means to create novel materials. In this study, based on waste grape seeds as the biowaste-derived carbon dots (G-BCDs), a straightforward one-pot green method was employed for the rapid detection of folic acid (FA). Owing to the internal filter effect and the static mixing quenching mechanism, the sensing principle of G-BCDs was effectively quenched by FA. The results showed fluorescence at an emission wavelength of 415 nm upon excitation at 330 nm with a quantum yield of 1.5%. Particularly, the FA sensing assay obtained a broad linear range of 2–220 μM and the limit of detection was 0.48 μM. In addition, the fluorescence probe was successfully utilized for detecting FA in tablets, blood, and urine samples, yielding desirable results, which indicated promising applications in the fields of biological and pharmaceutical analysis.

This paper focuses on methods for quantifying landfill gas emissions, including odor, odor generation mechanisms, odor emission characteristics according to the time of waste deposition, and odor measurement data from landfills. This study analyzed the concentration ranges and median values of 22 odor compounds measured at landfill gas collection wells and various landfill surface locations across both domestic and international landfill sites. These locations included active operational areas, final cover surfaces, and leachate treatment zones. The odor with the highest measured concentration at the landfill gas collection well was H2S (with a median value of 818,616 mg m–3). During landfill operations and on the surface of uncovered landfill layers, the concentrations of NH3 (with a median value of 1,613 mg m–3) and H2S (with a median value of 279.5 mg m–3) were found to be high . Concentrations of toluene, xylene, ketones, and sulfide odors were also high at covered landfill surfaces. Additionally, NH3, styrene, and H2S had high concentrations in the leachate treatment area. The odor intensity, measured on the surface of covered sanitary landfills for domestic waste, ranged from 6 to 2,080 mg m–3 (dilution to threshold). The concentrations of NH3 and H2S were relatively high in domestic sanitary landfills. The odorous compounds that contributed the most to odor intensity were nitrogen-containing odors, sulfur-containing odors, and aldehydes. In order to effectively manage landfill odors in the future, research should be continuously conducted to accurately measure and predict odor emission fluxes from landfills. In addition, it will be necessary to develop emission reduction technologies that take into account landfill odor emission characteristics.

This study analyzed the emission characteristics of major air pollutants (dust, nitrogen oxides, hydrogen chloride, and carbon monoxide) emitted from domestic public waste incineration facilities based on their operating elements. Using automatic measuring equipment for smokestacks (TMS), data was collected from 97 facilities from 2015 to 2023. The emission source unit (kg/ton) was evaluated based on the facility’s capacity, aging level, and incineration type. Emissions were calculated, and descriptive statistical analysis was performed based on the mean, standard deviation, and coefficient of variation. As a result of the analysis, it was found that the larger the facility capacity, the lower the average emission and volatility, which suggests that the operational stability of large facilities is high. On the other hand, facilities that had deteriorated for 10 to 15 years had the highest emission rates, and emissions decreased in facilities that were aged more than 20 years. In addition, the pyrolysis and high-temperature melting incineration facilities had lower NOx and HCl emissions than the conventional incineration type. Furthermore, CO showed the greatest volatility overall, which was found to be particularly difficult to manage in facilities in the early to mid stages of aging. These results provide empirical evidence that the structural characteristics and incineration type of incineration facilities have a significant impact on air pollutant emissions and can serve as useful basic data for policy-making, including for implementing region-wide initiatives and planning major repairs in the future.

Plastic wastes such as polyethylene terephthalate have recently been incorporated into coal as additives in coke manufacturing. Plastic waste results in the reduction of high-quality coal usage while protecting the environment. Using coal tar pitch as an additive in the coal blend causes an increase in fluidity during carbonization. The volatile matter released during carbonisation affects coal thermoplasticity, hence the carbon structural parameters. This paper investigates the role of polyethylene terephthalate and the mixture of polyethylene terephthalate and coal tar pitch on carbon structure formation during coal to coke transformation. The additives were blended with coking coal in 2, 3, 4, 5, and 10% wt. The results imply that incorporating coal tar pitch into the coal/ polyethylene terephthalate mixture improves the crystallite height of the resulting semi-coke. The addition of coal tar pitch and polyethylene teraphthalate blend to coking coal at a percentage below 5%wt. leads a positive impact on the crystallite height of the resulting coal char. The incorporation of coal tar pitch into the blend decreased the average interlayer spacing. At elevated temperatures, the polyethylene terephthalate in the blend causes an increase in the mean tortuosity. However, incorporating coal tar pitch into the blend led to about 3.3% decrease in mean tortuosity.