On airborne nano/micro-sized wear particles released from low-metallic automotive brakes

The paper addresses the wear particles released from commercially available “low-metallic” automotive brake pads subjected to brake dynamometer tests. Particle size distribution was measured in situ and the generated particles were collected. The collected fractions and the original bulk material were analyzed using several chemical and microscopic techniques. The experiments demonstrated that airborne wear particles with sizes between 10 nm and 20 μm were released into the air. The numbers of nanoparticles (<100 nm) were by three orders of magnitude larger when compared to the microparticles. A significant release of nanoparticles was measured when the average temperature of the rotor reached 300 °C, the combustion initiation temperature of organics present in brakes. In contrast to particle size distribution data, the microscopic analysis revealed the presence of nanoparticles, mostly in the form of agglomerates, in all captured fractions. The majority of elements present in the bulk material were also detected in the ultra-fine fraction of the wear particles.     

Indoor and outdoor sources of size-resolved mass concentration of particulate matter in a school gym—implications for exposure of exercising children

Introduction  

It has been noticed many times that schools are buildings with high levels of particulate matter concentrations. Several authors documented that concentrations of particulate matter in indoor school microenvironments exceed limits recommended by WHO namely when school buildings are situated near major roads with high traffic densities. In addition, exercise under conditions of high particulate concentrations may increase the adverse health effects, as the total particle deposition increases in proportion to minute ventilation, and the deposition fraction nearly doubles from rest to intense exercise.     

皂素提取头道液的典型有机物组成研究

利用紫外、红外拉曼光谱和GC/MS对传统皂素生产工艺、S-F工艺和E-S工艺头道液废水的有机物组成进行了分析。结果表明,传统工艺、S-F和E-S工艺头道液废水的有机物主要是醛类,此外,传统工艺头道液中检测到的22种有机物中,还有大量生物难降解的杂环类（12.24%）;而S-F和E-S工艺头道液中检测到的25种和31种有...     

Enhancement of chlorophenol sorption on soil by geophagous earthworms (Metaphire guillelmi)

Earthworms are the dominant soil biomass of many terrestrial ecosystems and markedly influence the physico-chemical and biological properties of soil; however, little is known about the effects of earthworm activities on the environmental behavior of micropollutants in soil. We studied the sorption and desorption of 2,4-dichlorophenol, 2,4,6-trichlorophenol, and pentachlorophenol on geophagous earthworm (anecic Metaphire guillelmi) casts of various aging times and on the parent soil. The casts were characteristic of lower pH and higher content of fine particles (silt and clay) than the parent soil. The sorption of the chlorophenols on the soil and casts were well fitted to linear isotherms, with sorption capacity in the order of pentachlorophenol > 2,4-dichlorophenol > 2,4,6-trichlorophenol. The sorption on the cast with different aging time was quite similar and was higher than on the parent soil. The sorption on the soil did not change between pH 7.07 of the soil and pH 6.76 of the casts. The desorption hysteresis of the chlorophenols on the soil and casts was compound specific and 2,4,6-trichlorophenol showed the highest hysteresis. The higher sorption capacity of the casts was not owing to the lowered pH of the casts, but mainly to the higher fine particles in the casts and the possible changes of nature of the soil organic matter through the earthworm gut passage. Our results indicate that geophagous earthworms may change sorption behavior and thus the bioavailability and transport of chlorophenols in soil. Earthworm effects should be considered when evaluating the environmental behavior and risk of organic pollutants in the ecosystems where earthworms are abundant.     

内电解技术处理有毒有害工业废水的应用进展

介绍了内电解技术的基本原理和特点,详细阐述了内电解技术处理印染、制药等多种有毒有害工业废水的应用进展,总结了内电解技术目前存在的主要问题和在工艺优化、新型材料和反应器形式开发三个方面的改进措施,展望了内电解技术未来的发展趋势和研究方向。     

Anaerobic Biodegradation of Polyvinyl Alcohol Modified by Extracellular Polysaccharides

This work focused on anaerobic biodegradation of blends composed of glycerol-plasticized polyvinyl alcohol (PVA) and biopolymer (starch, gellan, xanthan) in an aqueous environment, after inoculation with digested activated sludge from a municipal wastewater treatment plant. Glycerol degradability is comparable to degradability of used modifying agents. Modifying agents added in the 20–40 wt% range proportionally increased biodegradation degree (D_t) calculated from balance of transformed carbon in the system. Biodegradation degree of polysaccharides and glycerol attained 95% and over. For PVA it was only 6.5% (in breakdown times up to 500 h). Content of polysaccharides favorably affects biodegradation degree of polyvinyl alcohol blends, but at the expense of reduced mechanical properties of resultant products.     

响应面法优化西兰花总黄酮提取工艺的研究

利用响应面法优化西兰花总黄酮的提取工艺条件。在预试验的基础上,以乙醇为溶剂,提取西兰花总黄酮。选取提取温度、提取时间及液固比、乙醇浓度4个因素进行Box-Benhnken中心组合设计,利用响应面分析法对提取工艺参数进行优化。结果表明,西兰花总黄酮的提取工艺为:乙醇浓度90%,液固比30∶1,提取温度85.28℃,提取时间1.82h;预测值为0.887%,实际得率为0.853%,两者较接近,说明Box-Behnken设计结合响应面分析法可很好地对西兰花总黄酮提取工艺进行优化。     

含汞废弃荧光灯管处理现状及分析

废弃荧光灯管中含有金属汞,属于《国家危险废物名录》中的HW29含汞废物类,随意处置会破坏环境,危害人类健康,因此必须采取合理的方法对其进行处理。综合比较后发现资源化、无害化回收金属汞是最佳的处理方法。部分发达国家通过法律和技术手段的加强实现了对废弃荧光灯管的无害化回收处理,但我国在这方面的工作尚且不足,主要存在着灯管收集难、处理成本高等问题。因此,我国需要借鉴国外的管理经验,出台有效的法规措施,同时需要不断完善处理技术和大型工程建设。在我国节能减排和环境保护形势日益严峻的大环境下,辅之以合理的管理体制和技术手段,才能实现社会效益和经济效益双赢的局面。     

我国生物质能行业发展现状及建议

指出目前我国生物质能产业化的程度较低,普遍存在成本高、原料规模化供给不足、盲目投资、资金缺乏等现状,介绍了我国生物质能资源总量、类型和分布,以及生物质能行业的发展概况等,并参考国内外生物质能产业发展的经验,提出着重开发基于废弃物类原料的生物质能、开辟生物质能源农场、合理规划产业布局、改进政府扶持政策等建议。     

生态建设与环境承载力研究

由于对生态建设的艰巨性和长期性、资金需求、阻力估计不足,生态建设过于口号化,我国生态建设存在诸多问题。从环境承载力的定义入手,分析了生态建设与环境承载力的关系,提出了当前生态建设应采取发展生态农业、生态工业、生态旅游、倡导绿色消费、加强污染综合治理等措施。