离子交换纤维对金属氰络合物吸附性能的研究

采用强碱性离子交换纤维对含氰废水中主要离子铜氰络合物、锌氰络合物的吸附性能进行了研究。实验结果表明：含氰废水的pH在8—11范围内，纤维材料对金属氰络合物具有良好的吸附性能；纤维对铜氰络合物、锌氰络合物的吸附速率很快，4min左右就可达吸附平衡；温度对铜氰络合物、锌氰络合物吸附影响不大，纤维的这些吸附特点对工业应用非常有利。     

Kinetics of inorganic carbon utilization by microalgal biofilm in a flat plate photoreactor

A kinetic model was developed to describe inorganic carbon utilization by microalgae biofilm in a flat plate photoreactor. The model incorporates the fundamental mechanisms of diffusive mass transport and biological reaction of inorganic carbon by microalgal biofilm. An advanced numerical technique, the orthogonal collocation method and Gear's method, was employed to solve this kinetic model. The model solutions included the concentration profiles of inorganic carbon in the microalgal biofilm, the growths of suspended microalgae and microalgal biofilm, the effluent concentrations of inorganic carbon, and the flux of inorganic carbon from bulk liquid into biofilm. The batch kinetic test was independently conducted to determine biokinetic parameters used in the microalgal biofilm model simulation while initial thickness of microalgal biofilm were assumed. A laboratory-scale flat plate photoreactor with a high recycle flow rate was setup and conducted to verify the model. The volume of photoreactor is 60 l which yields a hydraulic retention time of 1.67 days. The model-generated inorganic carbon and the suspended microalgae concentration curves agreed well with those obtained in the laboratory-scale test. The fixation efficiencies of HCO(3)(-) and CO(2) are 98.5% and 90% at a steady-state condition, respectively. The concentration of suspended microalgal cell reached up to 12 mg/l at a maximum growth rate while the thickness of microalgal biofilm was estimated to be 104 microm at a steady-state condition. The approaches of experiments and model simulation presented in this study could be employed for the design of a flat plate photoreactor to treat CO(2) by microalgal biofilm in a fossil-fuel power plant.     

城市生活垃圾理化特性研究

本文对北京昌平冬季城市生活垃圾的理化特性进行了研究。测定了垃圾的物相组成,分析了垃圾中Ｃ、Ｈ、Ｏ、Ｎ、Ｓ的含量,进行了原生垃圾浸出毒性试验,测定了垃圾的发热量及其它化学性能,为探索城市垃圾的减量化、无害化、资源化的技术途径提供了技术支持。     

Comparison of properties of traditional and accelerated carbonated solidified/stabilized contaminated soils

The investigation of the long-term performance of solidified/stabilized (S/S) contaminated soils was carried out in a trial site in southeast UK. The soils were exposed to the maximum natural weathering for four years and sampled at various depths in a controlled manner. The chemical properties (e. g. , degree of carbonation (DOC), pH, electrical conductivity (EC)) and physical properties (e. g. , moisture content (MC), liquid limit (LL), plastic limit (PL), plasticity index (PI)) of the samples untreated and treated with the traditional and accelerated carbonated S/S processes were analyzed. Their variations on the depths of the soils were also studied. The result showed that the broad geotechnical properties of the soils, manifested in their PIs, were related to the concentration of the water soluble ions and in particular the free calcium ions. The samples treated with the accelerated carbonation technology (ACT), and the untreated samples contained limited number of free calcium ions in solutions and consequently interacted with waters in a similar way. Compared with the traditional cement-based S/S technology, e. g. , treatment with ordinary portland cement (OPC) or EnvirOceM, ACT caused the increase of the PI of the treated soil and made it more stable during long-term weathering. The PI values for the four soils ascended according to the order: the EnvirOceM soil, the OPC soil, the ACT soil, and the untreated soil while their pH and EC values descended according to the same order.     

Photoelectrocatalytic systems for simultaneous energy recovery and wastewater treatment: a review

Environmental Chemistry Letters - The rising energy conflicts and environmental pollution are calling for the rapid development of advanced techniques such as photoelectrocatalysis to...     

Measuring the bias of technical change of industrial energy and environment productivity in China: a global DEA-Malmquist productivity approach

Environmental Science and Pollution Research - Thanks to the booming industry, China has made a huge economic achievement during the past several decades. However, it is suffering severe...     

Speciation and quantification of vapor phases in soy biodiesel and waste cooking oil biodiesel

This study characterizes the compositions of two biodiesel vapors, soy biodiesel and waste cooking oil biodiesel, to provide a comprehensive understanding of biodiesels. Vapor phases were sampled by purging oil vapors through thermal desorption tubes which were then analyzed by the thermal desorption/GC/MS system. The results show that the compounds of biodiesel vapors can be divided into four groups. They include methyl esters (the main biodiesel components), oxygenated chemicals, alkanes and alkenes, and aromatics. The first two chemical groups are only found in biodiesel vapors, not in the diesel vapor emissions. The percentages of mean concentrations for methyl esters, oxygenated chemicals, alkanes and alkenes, and aromatics are 66.1%, 22.8%, 4.8% and 6.4%, respectively for soy biodiesel, and 35.8%, 35.9%, 27.9% and 0.3%, respectively for waste cooking oil biodiesel at a temperature of 25 ± 2 °C. These results show that biodiesels have fewer chemicals and lower concentrations in vapor phase than petroleum diesel, and the total emission rates are between one-sixteenth and one-sixth of that of diesel emission, corresponding to fuel evaporative emissions of loading losses of between 106 μg l⁻¹ and 283 μg l⁻¹. Although diesels generate more vapor phase emissions, biodiesels still generate considerable amount of vapor emissions, particularly the emissions from methyl esters and oxygenated chemicals. These two chemical groups are more reactive than alkanes and aromatics. Therefore, speciation and quantification of biodiesel vapor phases are important.     

黄土高原发展与生态改善

“陇中之苦,甲于天下”。这是黄土高原对甘肃定西地区和宁夏的西吉、海原、固原(西海固)的历史性结论。政府和国际援助多年来的努力使这一带的贫困状况有所减轻。但是至今这种状况仍然没有全部改观,特别是在远离城市和道路的深山。“三西”依然是中国最贫困的地区。究其原因,降水少而干旱,是生产效率低下的主因。频繁的旱灾往往使粮食绝收,人畜干渴而死;而夏秋集中的豪雨及多发的冰雹,又往往毁坏农作物和冲毁田地。     

集胞藻(Synechocystis sp. PCC6803)对砷吸收转化特性的初步研究

砷是一种广泛存在于环境中的有毒物质.集胞藻属于单细胞藻类,广泛分布在淡水生态环境中.采用营养液培养的方法探讨了集胞藻(Synechocystis sp.PCC6803)对砷的累积和转化特性.当集胞藻分别暴露于2和100 μM的无机As(Ⅲ)和As(Ⅴ)14 d后,体内的砷形态均以As(Ⅴ)为主,并且在100 μM浓度处...     

秸秆焚烧期间空气中细颗粒的组分特征

分析并探讨了南京市秸秆焚烧期间细颗粒中水溶性阴离子和铵,有机碳(OC)和元素碳(EC),以及Cu、Zn、Pb、Si等38种元素的含量和浓度.结果表明:细颗粒( PM2.5)水溶性离子中硫酸根浓度最高,其次是铵根离子,硝酸盐和氯离子,氟离子和亚硝酸盐最低.秸秆焚烧期间细颗粒样品中离子含量占26％,Si元素和金属所占份额为...