The study of age influence on human bone lead metabolism by using a simplified model and X-ray fluorescence data

Long term lead metabolism in the human body has never been fully understood due to the lack of human data in this area. The technological improvement of bone lead measurement systems has made bone lead data of substantial populations available. In this study, a set of X-ray fluorescence bone lead data was used to test Leggett's lead metabolism model (R. W. Leggett, Environ. Health Perspect., 1993a, 101, 598-616), especially the model of metabolism in bone. The data set includes the bone lead concentration of 539 occupationally exposed workers, of whom 327 were measured twice in five years. The bone lead concentrations of both cortical bone (tibia) and trabecular bone (calcaneus) were obtained by Cd-109 gamma-ray induced XRF measurement. The histories of blood lead concentration for these workers were used to regulate the input file of the model. The results show that the bone lead concentrations predicted by Leggett's model greatly underestimate the measured values, especially for older workers. This data set was then organized into five age groups. A new simplified model was applied to estimate the lead transfer rates between blood and lead compartments for these age groups. The original transfer rates and the new transfer rates are compared, and the differences are discussed. When the transfer rates derived from measured bone lead data were put into the input file of the model to replace the existing parameters, the predicted values were much closer to the measured values for both cortical bone and trabecular bone.     

絮凝法分离谷氨酸菌体的研究

采用絮凝法对味精发酵生产过程中发酵液中的菌体进行研究，得到无机凝聚剂与高分子絮凝剂复合配比使用是发酵液去除菌体的有效办法。对复合用药除菌后的谷氨酸发酵液和原谷氨酸发酵液进行谷氨酸回收的比较，谷氨酸的回收率提高了8．8％。     

Pd-MnO2 nanoparticles/TiO2 nanotube arrays (NTAs) photo-electrodes photo-catalytic properties and their ability of degrading Rhodamine B under visible light

Pd-MnO_2/TiO_2 nanotube arrays(NTAs) photo-electrodes were successfully fabricated via anodization and electro deposition subsequently; the obtained Pd-MnO_2/TiO_2 NTAs photo electrodes were analyzed by scanning electron microscopy(SEM), X-ray diffraction(XRD) and characterized accordingly. Moreover, the light harvesting and absorption properties were investigated via ultraviolet–visible diffuse reflectance spectrum(DRS); photo degradation efficiency was investigated via analyzing the photo catalytic degradation of Rhodamine B under visible illumination(xenon light). The performed analyses illustrated that Pd-MnO_2 codoped particles were successfully deposited onto the surface of the TiO_2 nanotube arrays;DRS results showed significant improvement in visible light absorption which was between400 and 700 nm. Finally, the photo catalytic degradation efficiency results of the designated organic pollutant(Rhodamine B) illustrated a superior photocatalytic(PC) efficiency of approximately 95% compared to the bare TiO_2 NTAs, which only exhibited a photo catalytic degradation efficiency of approximately 61%, thus it indicated the significant enhancement of the light absorption properties of fabricated photo electrodes and their yield of UOH radicals.     

菌渣中阿维菌素残留检测方法及其无害化工艺研究

文章建立了简单、快速的阿维菌素菌渣中阿维菌素残留量高校液相色谱检测方法以及利用水热法处理阿维菌素菌渣。采用固相萃取-高效液相色谱检测方法测定阿维菌素菌渣中阿维菌素残留量,提取剂为乙腈/水=4/1(V/V),采用HLB固相萃取柱进行净化。加标回收率90.3%~107.3%,相对标准偏差(RSD)为3.00%~5.69%,阿维2菌素标准曲线线性相关系数R~2=0.999 6,线性范围为1.0~1 000 mg/L。利用正交实验,水热法处理阿维菌素菌渣,在190℃的温度下处理2 h后,菌渣中阿维菌素残留量由991.30降至0.84 mg/kg,去除率达99.92%。处理前后的菌渣与有机肥标准作对比,除含水率外其余检测指标均达到有机肥标准要求。该项研究为阿维菌素菌渣的资源化利用提供了理论依据。     

不同装煤方式和炭化室高度的焦炉周边环境空气总悬浮颗粒物碳组分特征

研究了山西省4座典型焦炉周边环境空气中总悬浮颗粒物(TSP)碳组分特征,分析了不同装煤方式和炭化室高度对其的影响。结果表明:(1)焦炉周边环境空气中TSP质量浓度为711.95～2 938.41μg/m3,其中有机碳(OC)、元素碳(EC)的质量浓度分别为189.45～595.90、285.38～806.71μg/m3,总碳占TSP的质量分数为44.81%～67.45%;捣固焦炉周边的TSP及其碳组分浓度高于顶装焦炉,炭化室高度越高的焦炉周边环境空气中TSP及其碳组分浓度越低。(2)4座焦炉周边环境空气TSP中OC和EC质量比为0.66～1.04,说明焦炉周边环境空气中碳组分以一次污染为主。(3)4座焦炉周边环境空气TSP中碳组分的分歧系数为0.092～0.490,均小于0.5,总体来说装煤方式和炭化室高度都对焦炉周边环境空气TSP中碳组分的分布有一定影响,特别是装煤方式和炭化室高度都不同的焦炉周边环境空气TSP中碳组分差异较大。     

贵金属催化剂活性组分分布对催化湿式氧化处理非达霉素提炼废水的影响

采用均匀型和蛋白型Ru/TiO_2催化剂为湿式氧化催化剂,应用于催化湿式氧化非达霉素提炼废水,以出水COD和TOC去除率作为指标来评价2种催化剂的催化活性差异;采用实验室连续评价装置对柱状颗粒催化剂在不同pH、不同废水流量和不同温度下处理非达霉素提炼废水进行了优化评价。结果表明:在265℃、pH=4.1、废水流量为10 mL·h~(-1)时,催化剂的催化活性最高,故确定此条件为该废水处理的最优条件;同时对比均匀型和蛋白型2种催化剂,蛋白型催化剂具有更高的催化效率;结合SEM及N_(2~-)物理吸附结果,推断蛋白型催化剂活性组分集中分布在催化剂颗粒的较浅层,有利于降低反应过程中的扩散阻力,提高贵金属活性组分的利用率,进而提高催化剂的催化活性。以上结果对开发高效湿式氧化催化剂,充分利用贵金属活性组分降低催化剂成本具有十分重要的意义。     

论当代大学生的信息素养教育

国民信息素养的高低已成为一个国家在全球竞争中获得优势地位的关键,信息素养教育在全世界范围内备受重视。本文以信息素养为出发点,以当今高校对在校大学生信息素养培训的新要求为依据,通过信息的选择、检索、利用,个人创新和文化素养等五个方面的教育,论述了如何培养高校学生信息素养,使学生养成终身学习的习惯。     

Improvement of sludge dewaterability with modified cinder via affecting EPS

The relationship between the improvement of sludge dewaterability and variation of organic matters has been studied in the process of sludge pre-conditioning with modified cinder, especially for extracellular polymeric substances (EPS) in the sludge. During the conditioning process, the decreases of total organic carbon (TOC) and soluble chemical oxygen demand (SCOD) were obviously in the supernatant especially for the acid modified cinder (ACMC), which could be attributed to the processes of adsorption and sweeping. The reduction of polysaccharide and protein in supernatant indicated that ACMC might adsorb EPS so that the tightly bound EPS (TB-EPS) decreased in sludge. In the case of ACMC addition with 24 g·L^–1, SRF of the sludge decreased from 7.85 × 10¹² m·kg^–1 to 2.06 × 10¹² m·kg^–1, and the filter cake moisture decreased from 85% to 60%. The reconstruction of “floc mass” was confirmed as the main sludge conditioning mechanism. ACMC promoted the dewatering performance through the charge neutralization and adsorption bridging with the negative EPS, and provided firm and dense structure for sludge floc as skeleton builder. The passages for water quick transmitting were built to avoid collapsing during the high-pressure process.

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O3/BAF工艺系统中有机物生物降解数学模型

研究臭氧预氧化/曝气生物滤池（O₃/BAF）联合工艺深度处理实际城市污水二级出水过程中,后续BAF系统中有机物的生物降解数学模型。以有机底物浓度、填料层高度两个基本变量为控制条件,研究BAF的总体运行常数和填料特性常数,得出BAF有机物生物降解动力学方程为S_e/S₀=exp(－Kh/qSⁿ₀)。出水与进水COD浓度比值（S_e/S₀）的对数与反应器填料高度（h）之间可表达成一次函数关系。在不同的进水浓度（S₀）下,根据ln（S_e/S₀）~h和关系式m=K/qSⁿ₀,得到方程ln(q_m)=－nln(S₀)+lnK。BAF总体运行常数K和填料特性常数n分别为1.708和0.5063。该模型对BAF工艺有如下指导意义：可以根据设计流量、进水有机物浓度和出水浓度,初步确定BAF的尺寸（如横截面积、高度等）。     

离子交换法选择性回收污泥厌氧消化液中的磷

为探讨高效选择性回收污泥厌氧消化液中磷的离子交换方法,采用静态实验和动态实验研究了4种阴离子交换树脂（D213、D202、D301和DSQ）的磷回收性能,筛选了适合富磷污泥厌氧消化液选择性磷回收的高交换容量树脂。实验结果表明,D213、D202、D301和DSQ 4种树脂对正磷浓度为70 mg/L的厌氧消化液进行动态处理时,其最大穿透体积分别为3、7、17和90 BV;DSQ树脂磷交换容量远高于其他3种树脂,达到6 860 mg P/L湿树脂,是目前报道的高磷交换容量树脂的3~4倍;DSQ树脂能有效地抵抗厌氧消化液中有机质和硫酸根等阴离子的干扰;用NaOH溶液再生DSQ树脂并回收磷,磷洗脱率超过96%,洗脱液是高浓度含磷液,可作为磷矿石的优质替代品。研究表明,DSQ树脂是一种高效选择性分离磷的树脂,适用于污泥厌氧消化液的磷回收。