几种混凝剂处理煤气洗涤废水的比较

用４种常用的混凝剂Ａｌ２（ＳＯ４）３,ＰＡＣ,ＰＦＳ及ＦｅＳＯ４分别对煤气洗涤废水进行了混凝实验研究,结果表明,使用上述４种药剂对废水ＣＯＤｃｒ最高去除率分别为６３．９％,６７．４％,６１．３％和５７．４％;乳化油去除率分别为７１．６％,７５．６％,７４．８％和７０．５％,浊度去除率分别为９３．４％,９４．１％〈９５．６５和９９．１％,而从经济效益上看,４种药剂去除每ｋｇ废水中ＣＯＤｃｒ所需药剂费     

Reduced biodegradation of benzonitrile in soil containing wheat-residue-derived ash

Burning of crop residues is a common agricultural practice that incorporates the resulting particulate matter (ash) of high adsorptivity into soils. To investigate the effect of ash on the biodegradation of pesticides in soils, we measured the sorption, desorption, and biodegradation of benzonitrile in a silt loam in the presence and absence of an ash resulting from burning of wheat (Triticum aestivum L.) residue. Biodegradation experiments were conducted by inoculating sorbent slurries with a pure culture of benzonitrile-degrading bacteria (Nocardia sp.). Both liquid- and sorbed-phase benzonitrile concentrations were quantified over time. The ash was approximately 2000 times more effective per unit mass than the soil in sorbing benzonitrile. Amendment of the soil with 1% ash (by weight) resulted in a 10-fold increase in sorption. Sorption of benzonitrile by the ash significantly decreased the solution-phase concentration in the slurries of ash and ash-amended soil. Desorption of benzonitrile from the ash required approximately 60 min to complete, whereas approximately 20 min were required for desorption from the soil. Benzonitrile in the extracts of various sorbents and soil slurry was completely degraded within 500 min. However, the degradation was substantially reduced in the presence of the ash. At 2000 min, only 20% of benzonitrile in ash slurry and only 44% in ash-amended soil slurry were degraded. An acclimation period of approximately 100 min was observed in extracts and slurries containing the ash. Substantial reduction in the biodegradation of benzonitrile in the presence of wheat ash was apparently due to sorption of benzonitrile by the ash, slow desorption from the ash, and the increased acclimation period. Our results suggest that the presence of crop-residue-derived ash may increase the persistence of pesticides in agricultural soils.     

电子废弃物管理研究热点对比与可视化分析

随着电子产品消费量的日益增多,电子废弃物(WEEE)的数量也不断增加,WEEE管理已成为全球关注的热点环境问题。以Web of Science核心数据库和中国知网(CNKI)全文数据库相关文献作为样本,借助Citespace软件对2007—2017年国内外WEEE管理文献进行了可视化分析,旨在理清中国与国际WEEE管理的发展脉络、研究热点和前沿趋势。结果表明:(1)国际关于WEEE管理的热度不断增加,研究重点由发达国家逐渐转向发展中国家和地区;(2)WEEE管理的研究方法、研究内容和研究角度日益丰富,生产者责任延伸制度、绿色设计、生命周期评价、逆向物流和工业生态学都成为研究的热点;(3)未来中国WEEE管理研究应注重WEEE管理的立法建设和理论技术创新以及大数据与信息系统在WEEE管理方面的应用。     

Feasibility of iron scraps for enhancing nitrification of domestic wastewater at low temperatures

Environmental Science and Pollution Research - The development of an effective approach to improve low-temperature nitrification of domestic wastewater remains an important issue that needs to be...     

Regional convergence of energy-environmental efficiency: from the perspective of environmental constraints

Environmental Science and Pollution Research - This paper conducts a convergence analysis on the energy-environmental efficiency to explore the differences between regions that reflect the...     

Impacts of national park tourism sites: a perceptual analysis from residents of three spatial levels of local communities in Banff national park

Environment, Development and Sustainability - Communities next to national parks, known as gateway communities, can benefit from national park development. Gateway communities are unique and...     

Exploring new ideas for sustainable development of urban agglomerations-based on the coupling of people’s livelihood and environmental governance

Environment, Development and Sustainability - Peoples’ livelihood and environmental governance are interrelated and interact with each other, which is a new starting point for the study of...     

乌梁素海沉积物溶解性有机质荧光光谱特性

采用三维荧光光谱技术(3DEEM)研究了乌梁素海沉积物溶解性有机质的结构组成特征.结果表明,乌梁素海沉积物溶解性有机质出现了6种荧光峰,分别代表类蛋白荧光物质和类富里酸荧光物质,且不同湖区沉积物溶解性有机质结构组成具有一定差异性.乌梁素海沉积物DOM的荧光指数处于1.74~1.96之间,及其DOM来源具有陆源和内源的双重特性,其中陆源主要来自西部河套灌区农田退水输入,内源主要来自芦苇等大型挺水植物死亡腐烂分解.因此,控制河套灌区农田退水排入以及抑制芦苇等挺水植物大量生长是保护乌梁素海生态环境和控制其富营养化的有效措施.     

两种空气自动监测系统的比较

国产长光程空气自动监测系统是中国自行研制的更为先进、更具自动化的系统，24h点式仪器是老式空气检测仪器，对这两种新、老仪器的比较可以看出在运行过程中的利弊。     

由硫酸亚铁（绿矾）制取还原铁粉的工艺研究

提出了一种新的绿矾综合利用的途径,即绿矾经碳酸盐转化,然后采用无烟煤作还原剂,CaCO3为添加剂,进行高温还原焙烧制取还原铁粉.先将绿矾用水溶解,用理论量1.2倍的（NH4）2CO3将FeSO4转化为FeCO3,FeCO3焙烧的最佳条件是FeCO3∶无烟煤∶CaCO3为100∶60∶8,焙烧温度为1000℃,焙烧时间为4.5 h.粗还原铁粉化学成分除C含量较高外,符合国家有关标准,900℃左右经氢气精还原1 h所得精还原铁粉化学成分的各项指标,均达到或优于国家有关标准的要求.