Finned Single-pass Solar Air Heaters with Wire Mesh as an Absorber Plate

Single-pass solar air heaters (SAHs) with two and six fins attached and packed with wire mesh layers were experimentally investigated. Wire mesh layers were used between the fins in the place of an absorber plate. The effects of air mass flow rate on the outlet temperature and thermal efficiency were studied. The results showed an increase in the thermal efficiency as the air mass flow rate was increased. The range of the mass flow rate used in this work was between 0.0121and 0.042 kg/s. It was found that for the same mass flow rate the SAH having six fins has higher efficiency compared to the system that has two fins. The maximum efficiencies for the SAHs were obtained at the mass flow rate of 0.042 kg/s. The maximum efficiencies for the six-finned and two-finned SAHs were 79.81% and 71.8%, respectively. In addition, the maximum temperature difference between the inlet and the outlet, ΔT, for the SAH with six fins exceeded the two-finned SAH for the same mass flow rates. The maximum ΔT was 51.1°C for the six-finned SAH and 44.2°C for the two-finned SAH. As expected, the maximum ΔT for each SAH was obtained at the lowest air mass flow rate (i.e., 0.0121 kg/s). A substantial enhancement in the thermal efficiency was achieved in comparison to the results of a single-flow packed bed collector with those of conventional collectors.     

壳聚糖改性竹制粉末活性炭吸附剂对微囊藻毒素的吸附特性研究

研究了壳聚糖改性的竹制粉末活性炭吸附剂对饮用水中微囊藻毒素Microcystin-RR(MCRR)的吸附效果和机理.结果表明,这种新合成的吸附剂具有一定的孔结构,比表面积为203.63m·2g-1,平均孔径为7.23nm,并且具有较高比例的介孔分布,这种特性使得其对最长分子尺寸为2.86nm的MCRR具有较好的捕捉效果.吸附动力学实验表明,接触时间达到100min后,吸附趋于稳定,该吸附剂对MCRR的吸附行为可以用Langmuir模型(Ce/Qe=0.014Ce+0.81,R2=0.99)和Freundlich模型(lnQe=0.61lnCe+1.04,R2=0.99)较好地描述;在中性条件下该吸附剂对MCRR的最大吸附量达到69.93μg·g-1,具有较强的吸附能力.受吸附剂本身等电点及MCRR分子带电性能的影响,吸附剂对MCRR的吸附受pH影响较大,在pH=3时吸附能力最强;此外,天然有机物(NOM)的存在会对MCRR的吸附产生明显的竞争作用.脱附实验表明,改变脱附溶液的pH对提高脱附效率影响不大,甲醇作为脱附剂具有较好的脱附效果,脱附率可达到96%.     

水合氧化铁对含磷废水的吸附特性研究

以Fe(NO3)3为前驱物,制备了水合氧化铁吸附剂样品,以NaOH为解吸剂,研究了样品对模拟废水中磷酸根的吸附和解吸性能。结果表明,水合氧化铁对磷酸根有较好的吸附效果;随着pH的降低,水合氧化铁对磷酸根的吸附能力增强,在pH为2时吸附达92.5%;吸附前15 min吸附速率较快,约150 min达到平衡,吸附动力学曲线符合二级动力学模型;用水合氧化铁对初始浓度为50~100 mg/L模拟含磷废水吸附,随着初始浓度的增大,磷的去除率下降;水合氧化铁对磷酸根的吸附等温线较符合Langmuir吸附模型;用NaOH对水合氧化铁行解吸,浓度为40 g/L有最好的解吸率,60 min时达到解吸平衡。     

Improved utilization of active sites for phosphorus adsorption in FeOOH/anion exchanger nanocomposites via a glycol-solvothermal synthesis strategy

Metal oxide/hydroxide-based nanocomposite adsorbents with porous supporting matrices have been recognized as efficient adsorbents for phosphorus recovery. Aiming at satisfying increasingly restrictive environmental requirements involving improving metal site utilization and lowering metal leakage risk, a glycol-solvothermal confined-space synthesis strategy was proposed for the fabrication of Fe OOH/anion exchanger nanocomposites（Fe/900s）with enhanced metal site utilization and reduced metal lea...     

甲烷氯化物废水治理工艺的技术应用

在氯碱工业加工过程中会产生大量的甲烷氯化物废水,废水中含有大量的甲烷氯化物,该类废水不易处理,极大地影响了后续废水处理工作的开展。本文以某司甲烷氯化物具体试验为例,探讨高分子吸附剂在甲烷氯化物废水处理过程中的应用,在利用高分子吸附剂进行吸附的同时通过蒸汽吹脱使树脂中富集下来的甲烷氯化物得到分离回收,从而实现了废水的资源化,达到治废与资源利用的双重效果。     

Ion adsorption components in liquid/solid systems

Experiments on Zn^2＋ and Cd^2＋ adsorptions on vermiculite in aqueous solutions were conducted to investigate the widely observed adsorbent concentration effect on the traditionally defined adsorption isotherm in the adsorbate range 25--500 mg/L and adsorbent range 10--150 g/L. The results showed that the equilibrium ion adsorption density did not correspond to a unique equilibrium ion concentration in liquid phase. Three adsorbate/adsorbent ratios, the equilibrium adsorption density, the ratio of equilibrium adsorbate concentration in liquid phase to adsorbent concentration, and the ratio of initial adsorbate concentration to adsorbent concentration, were found to be related with unique values in the tested range. Based on the assumption that the equilibrium state of a liquid/solid adsorption system is determined by four mutually related components： adsorbate in liquid phase, adsorbate in solid phase, uncovered adsorption site and covered adsorption site, and that the equilibrium chemical potentials of these components should be equalized, a new model was presented for describing ion adsorption isotherm in liquid/solid systems. The proposed model fit well the experimental data obtained from the examined samples.     

毛细柱与填充柱气相色谱法分析环境中甲基汞

介绍巯基棉富集－毛细管气相色谱法测定环境水,沉积物和土壤样口中痕量基汞的分析方法,对毛细管柱与填充柱分析样品中甲基汞的精度度,检测限进行了对比。研究表明,填充柱分析甲基汞的检测限为２ｐｇ,而毛细管柱色谱对甲基汞的检测限为０．５ｇｐ。     

农作物秸秆酶解与磷细菌肥的生产

以农作物秸秆为酶水解原料 ,用纤维素酶进行酶水解 ,水解液用于培养磷细菌肥生产菌 ,再用粉碎至一定粒度的作物秸秆对培养菌液进行吸附。实验结果表明 ,经酶解得到的水解液在添加一定的辅料后 ,可以作为培养磷细菌的料液。适宜条件下 ,菌量可达 5 1× 1 0 8/ml。     

Combustion in porous media and its applications – A comprehensive survey

The rapid advances in technology and improved living standard of the society necessitate abundant use of fossil fuels which poses two major challenges to any nation. One is fast depletion of fossil fuel resources; the other is environmental pollution. The porous medium combustion (PMC) has proved to be one of the technically and economically feasible options to tackle the aforesaid problems to a remarkable extent. PMC has interesting advantages compared with free flame combustion due to the higher burning rates, the increased power dynamic range, the extension of the lean flammability limits, and the low emissions of pollutants. This article provides a comprehensive picture of the global scenario of research and developments in PMC and its applications that enable a researcher to decide the direction of further investigation. The works published so far in this area are reviewed, classified according to their objectives and presented in an organized manner with general conclusions. A separate section is devoted for the numerical modeling of PMC.     

改性花生壳对苯酚的吸附

以花生壳为原料,使用环氧氯丙烷、二甲胺及吡啶,以N,N-二甲基甲酰胺为反应介质改性花生壳。结果表明:改性花生壳对苯酚的去除效果优于未改性花生壳。在实验条件下,吸附剂的吸附量在溶液pH为9,吸附时间为120 min时达到最大;溶液离子强度对吸附的影响较大。分析了该反应体系的动力学和热力学参数,改性花生壳吸附苯酚过程拟用准二级动力学模型处理,计算得出平衡吸附量与实验值相符。改性花生壳对苯酚的吸附符合Langmuir和Freundlich等温模式,R2均大于0.98,Qmax在84.49～108.76 mg/g之间,Freundlich模式的吸附强度n值在1.211～1.262之间,热力学参数△G、△H、△S表明改性花生壳对苯酚的吸附过程是自发、吸热过程。