Porous materials produced from incineration ash using thermal plasma technology

This study presents a novel thermal plasma melting technique for neutralizing and recycling municipal solid waste incinerator (MSWI) ash residues. MSWI ash residues were converted into water-quenched vitrified slag using plasma vitrification, which is environmentally benign. Slag is adopted as a raw material in producing porous materials for architectural and decorative applications, eliminating the problem of its disposal. Porous materials are produced using water-quenched vitrified slag with Portland cement and foaming agent. The true density, bulk density, porosity and water absorption ratio of the foamed specimens are studied here by varying the size of the slag particles, the water-to-solid ratio, and the ratio of the weights of the core materials, including the water-quenched vitrified slag and cement. The thermal conductivity and flexural strength of porous panels are also determined. The experimental results show the bulk density and the porosity of the porous materials are 0.9–1.2 g cm^?3 and 50–60%, respectively, and the pore structure has a closed form. The thermal conductivity of the porous material is 0.1946 W m^?1 K^?1. Therefore, the slag composite materials are lightweight and thermal insulators having considerable potential for building applications.     

Longitudinal data analysis in support of functional stability concepts for leachate management at closed municipal landfills

Landfill functional stability provides a target that supports no environmental threat at the relevant point of exposure in the absence of active control systems. With respect to leachate management, this study investigates “gateway” indicators for functional stability in terms of the predictability of leachate characteristics, and thus potential threat to water quality posed by leachate emissions. Historical studies conducted on changes in municipal solid waste (MSW) leachate concentrations over time (longitudinal analysis) have concentrated on indicator compounds, primarily chemical oxygen demand (COD) and biochemical oxygen demand (BOD). However, validation of these studies using an expanded database and larger constituent sets has not been performed. This study evaluated leachate data using a mixed-effects regression model to determine the extent to which leachate constituent degradation can be predicted based on waste age or operational practices. The final dataset analyzed consisted of a total of 1402 samples from 101 MSW landfills. Results from the study indicated that all leachate constituents exhibit a decreasing trend with time in the post-closure period, with 16 of the 25 target analytes and aggregate classes exhibiting a statistically significant trend consistent with well-studied indicators such as BOD. Decreasing trends in BOD concentration after landfill closure can thus be considered representative of trends for many leachate constituents of concern.     

覆膜滤料过滤性能的试验研究

对覆膜滤料与普通（渗膜）滤料的过滤性能进行了试验研究,结果显示：与普通滤料相比,覆膜滤料具有过滤效率高、运行阻力低、使用寿命长等特点。覆膜滤料的过滤性能更佳,更能满足烟尘过滤的要求。     

Material flow analysis for a sustainable resource management in island ecosystems

The Galapagos Archipelago (Ecuador) is one of the most well-known natural sites in the world for its unique biodiversity. This sensitive ecosystem is at risk due to a problematic equilibrium between its conservation policy and development demand. To contribute to implementing integrated sustainable resource management in the Galapagos Islands, a material flow analysis (MFA) of Santa Cruz – the island with the highest anthropic pressure in the archipelago – has been performed, outlining a quantitative and qualitative assessment of the direct flow of goods throughout the system. MFA outcomes have been used to evaluate and forecast the impact of some policies and strategies on the local system, focusing in particular on fossil fuel consumption and local agricultural production. This case study stresses the need to introduce a local MFA protocol to decision-makers’ toolbox, as it provides quantitative assessments on a broad spectrum of local development issues.     

吸波材料反射率的现场测量方法

通过对微波暗室中安装在墙壁上的吸波材料反射率的现场测量方法的研究,采用矢量网络分析仪对吸波材料反射率进行现场测量时,利用时域门技术来减小暗室现场对吸波材料反射率测量的影响,通过比较标准金属板和吸波材料的测量值得到吸波材料的反射率。     

Dielectric barrier discharge plasma-assisted modification of g-C3N4/Ag2O/TiO2-NRs composite enhanced photoelectrocatalytic activity

Dielectric barrier discharge (DBD) plasma applied as surface treatment technology was employed for the modification of Ag₂O and graphitic carbon nitride (g-C₃N₄) powders. Subsequently, the pretreated powders were sequentially loaded onto TiO₂ nanorods (TiO₂-NRs) via electro-deposition, followed by calcination at N₂ atmosphere. The results indicated that at the optimal plasma discharge time of 5 min for modification of g-C₃N₄ and Ag₂O, photocurrent density of ternary composite was 6 times to bare TiO₂-NRs under UV-visible light irradiation. Phenol was degraded by using DBD plasma-modified g-C₃N₄/Ag₂O/TiO₂-NRs electrode to analyze the photoelectrocatalytic performance. The removal rate of phenol for g-C₃N₄-5/Ag₂O-5/TiO₂-NRs electrode was about 3.07 times to that for TiO₂-NRs electrode. During active species scavengers’ analysis, superoxide radicals and hydroxyl radicals were the main oxidation active species for pollutants degradation. A possible electron-hole separation and transfer mechanism of ternary composite with high photoelectrocatalytic performance was proposed.     

Coupled biodegradation of p-nitrophenol and p-aminophenol in bioelectrochemical system: Mechanism and microbial functional diversity

Biodegradation mechanisms and microbial functional diversity during coupled p-nitrophenol (PNP) and p-aminophenol (PAP) degradation were studied in a bioelectrochemical system. PNP in the biocathode and PAP in the bioanode were almost completely removed within 28hr and 68hr respectively. The degradation followed the steps including hydrating hydroxyalkylation, dehydrogenating carbonylation, and hydrolating ring cleavage, etc. Metagemomic analysis based on the KEGG and eggNOG database annotations revealed the microbial composition and functional genes/enzymes related to phenol degradation in the system. The predominant bacteria genera were Lautropia, Pandoraea, Thiobacillus, Ignavibacterium, Truepera and Hyphomicrobium. The recognized biodegradation genes/enzymes related to pollutant degradation were as follows: pmo, hbd, & ppo for phenol degradation, nzba, amie, & badh for aromatic degradation, and CYP & p450 for xenobiotics degradation, etc. The co-occurrence of ARGs (antibiotic resistant genes), such as adeF, MexJ, ErmF, PDC-93 and Escherichia_coli_mdfA, etc., were annotated in CARD database during the biodegradation process. The Proteobacteria & Actinobacteria phylum was the primary host of both the biodegradation genes & ARGs in this system. The microbial functional diversity ensured the effective biodegradation of the phenol pollutants in the bioelectrochemical system.     

典型室内公共场所灰尘中PBDEs污染特征及源解析

为探索以多溴联苯醚（PBDEs）为代表的半挥发性有机化合物在典型室内公共场所中的污染特征及与材料的关系,在网咖、电子市场、建材市场、商场和图书城5类典型公共场所采集分析了灰尘样品,利用环境模拟舱研究了不同污染源材料中PBDEs的挥发强度系数（K_vsPBDEs）、衰减半衰期,结合主成分分析（PCA）分析了PBDEs的浓度与不同室内材料间的关系.结果表明,杭州5类典型室内公共场所灰尘中∑₁₄PBDEs的平均值分别为：网咖（2471.75ng/g）>电子市场（1071.77ng/g）>建材市场（900.63ng/g）>商场（441.27ng/g）>图书城（243.36ng/g）.所选取的10种室内典型污染源材料中∑₁₄PBDEs含量最高的为保温棉（91.61μg/g）,最低的为电路板（7.97μg/g）;K_vsPBDEs最高的为电线[14.04×10⁴μg/（g·m²）],最低的是纤维墙纸[0.87×10⁴μg/（g·m²）];塑料地毯、保温棉和纤维墙纸在40℃下的衰减半衰期分别为192,375和61d.研究发现室内公共场所中PBDEs的浓度与不同材料有关：网咖中PBDEs主要来自于纤维墙纸和电线;超市和图书城中PBDEs主要来自于陶瓷阻燃布和混纺地毯;建材市场中PBDEs主要来自于保温棉、电路板和塑料墙纸;电子市场中PBDEs主要来自于纤维阻燃布和电线.     

中国报废汽车中铂族金属回收潜力估算

基于Gompertz模型预测中国2018~2050年民用汽车的社会保有量;在此基础上,采用物质流分析方法估算得出我国汽车高峰报废年限大约为9a.然后,通过市场供给A模型预测我国2018~2025年汽车报废量,结果显示,我国汽车报废量到2025年将达到2535.05万辆,并且地理空间分布极不均衡.基于上述汽车报废量的时空分布,测算不同技术发展情景下废汽车三元催化剂中的铂族金属回收潜力和需求量.结果显示：如果按照当前催化剂消耗水平,全国铂族金属的需求量均在2019年达到峰值,铂钯铑分别达到4.57,65.70,7.92t,有望实现行业内闭环供应;如果以欧盟汽车尾气治理标准为目标,而现有汽车技术不发生根本变化,需求量将大幅增加,铂钯铑分别在2020年达到峰值85.01,109.38,8.37t,存在严重的供需矛盾.为此,建议在汽车生产者责任延伸制度中,关注废催化剂的回收和再生利用,以促进前端生产环节在不同技术选择中考虑稀贵金属的供给限制.     

等离子体技术在材料领域中的应用研究进展

详述了等离子体在材料领域的应用研究进展,在材料表面处理方面可实现材料的表面粗糙化、表面清洁、表面化学基团引入和表面亲水性调变等,在催化材料制备方面可用于催化剂的还原、氧化、掺杂、刻蚀以及特殊化合物的合成等。还分析了等离子体技术在材料制备领域具备诸多优势,但仍然面临一些挑战,如等离子体处理具有时效性、处理量小、等离子体发生作用机制不清晰、工程放大困难等。因此,需要从等离子体反应机理及工程技术两个层面进行更深入研究,以期该技术在材料领域获得更广泛的应用。