鸟粪石分析与表征技术综述

对X射线衍射（XRD）、傅里叶红外光谱（FT—IR）和拉曼光谱（Ralnan）、热分析（TGA）及化学分析法等技术用于分析和表征鸟粪石的最新研究进展进行了综述。表明X射线衍射、傅里叶红外光谱和拉曼光谱等能定性判断所得沉淀中是否含有鸟粪石,而难以定量分析鸟粪石含量。通过元素分析以及由此而建立的鸟粪石含量计算方法可以定量确定沉淀中鸟粪石的含量。热分析能提供热性能信息从而为所得沉淀的干燥处理过程提供有用的依据。     

Characterization of refuse landfill leachates of three di erent stages in landfill stabilization process

Landfill leachates with di erent ages (mature leachate, 11 years; semi-mature leachate, 5 years; fresh leachate, under operation) were collected from Laogang Refuse Landfill, Shanghai to characterize the colloid size distribution and variations of leachate. These leachates were separated using micro-filtration and ultra-filtration into specific size fractions, i.e., suspended particles (SP) (> 1.2 m), coarse colloids (CC) (1.2–0.45 m), fine colloids (FC) (0.45 m, 5 kDa/1 kDa molecular weight (MW)), and dissolved organic matters (DM, < 5 kDa/1 kDa MW). The specific colloids in each size fraction were quantified and characterized through chemical oxygen demands (COD), total solid (TS), pH, NH4 +-N, total organic carbon (TOC) and fixed solid (FS). It was found that COD, NH4 +-N and TS in leachate decreased significantly over ages, while pH increased. The dissolved fractions (< 5 kDa/1 kDa) dominated (over 50%) in three leachates in terms of COD, and the organic matter content in dissolved fraction of leachates decreased and the inorganic matter increased as the disposal time extended, with the TOC/COD ratio 30%–7%. Dissolved fractions decreased from 82% to 40% in terms of TOC as the disposal time extended, suggested that the organic matter remained in leachate would form into middle molecular weight substances during the degradation process.     

Characterization of refuse landfill leachates of three different stages in landfill stabilization process

hate would formed into middle molecular weight substances during the degradation process.     

2株球形棕囊藻溶藻细菌的分离及鉴定

从珠海赤潮海水中分离出2株溶藻细菌Y01和Y04,对球形棕囊藻均有显著的溶藻效果.结果表明,溶藻细菌Y01和Y04均为革兰氏阳性菌,对球形棕囊藻的溶解作用时间为6 d.借助显微镜及扫描电镜等观察Y01和Y04溶藻过程,发现2株溶藻细菌的溶藻方式均为直接裂解藻细胞.溶藻细菌Y01和Y04的16S rDNA系列分析表明,溶...     

污泥中一株产耐高温蛋白酶菌株的分离、鉴定及酶学特性

蛋白酶是水解蛋白质肽键的一类酶的总称,它可将蛋白质分解、转化为氨基酸,从而被动植物体直接吸收利用.基于此,以江苏省无锡市太湖新城污水处理厂的污泥为材料,通过观察水解圈大小和蛋白酶活性测定等方法,从中筛选出一株高产蛋白酶菌株TC16.同时,参照《伯杰氏细菌鉴定手册》和《常见细菌鉴定手册》,根据其形态学特征、生理生化特性,并结合16SrDNA序列的比对分析结果发现,该菌属于芽孢杆菌属菌株.对其酶学性质的研究发现,从该污泥中分离得到的菌株TC16分泌的胞外蛋白水解酶的活性最高可达621U·mL-1.研究表明,与其他芽孢杆菌属菌株相比,TC16菌株分泌的蛋白酶具有较高的酶活性,且具有较宽范围的pH和温度耐受性.     

外绝缘用液体硅橡胶老化现象的微观表征

本文针对近年来出现在一些变电站SF6电压、电流互感器的液体硅橡胶绝缘护套出现龟裂老化这一现象,对发生老化的硅橡胶材料进行了性能测试和试验,并利用红外光谱分析、XPS分析、热失重等手段分析了其微观结构和物质组成的变化。研究发现老化后的液体硅橡胶中Si-C、Si-O官能团和Si、C、O元素的相对含量发生了变化,且随着老化程度的增加呈现出较为明显的规律,老化越严重,Si-C键含量越少,C元素的含量越少,O元素含量越多。本文认为,用官能团含量、元素相对含量可以准确地表征液体硅橡胶材料的老化程度。通过对不同老化程度的液体硅橡胶进行的憎水性、耐漏电起痕性能的试验也证实了本文的观点。     

Metal associations in anoxic sediments and changes following upland disposal†

The ecological effects of heavy metals in contaminated sediments are more determined by the chemical form and reactivity than by the level of accumulation. Dredging of anoxic sediments and disposal on land is attended by changes of redox conditions. Under oxidizing conditions some controlling solid compounds may change gradually thus changing the solubility of certain metals.

Chemical extraction experiments for estimating characteristic association forms of heavy metals in anoxic sediments were carried out, both under presence and absence of air during the analytical procedure. Drying of the sediment decreases the proportion of the sulfidic metal fractions to a stronger degree, and oxidized Cd and Zn are found in the most available, exchangeable fraction.

With respect to long‐term effects acidification of poorly buffered sludges after disposal on land is probably the most important factor affecting metal associations and mobility. For many metal examples a linear relationship has been found between decreasing pH values and increasing dissolved metal concentrations. To quantify these relationships and for better comparison of samples a simple test procedure is proposed which is based on pH differences before and after addition of acid.     

PIXE characterization of PM10 and PM2.5 particulates sizes collected in Ikoyi Lagos,Nigeria

Ambient concentrations of PM₁₀ (x?≤?10?µm) and PM_2.5 (x?≤?2.5?µm) particulate fractions collected from Ikoyi Lagos, Nigeria, as well as their elemental compositions are presented in this study. Both size-segregated fractions were collected using a double staged ‘Gent’ stack filter unit sampler. Elemental characterizations of dust laden filters were carried out using proton-induced X-ray emission (PIXE) technique. Twenty-two elements (Si, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Pb, Br, Rb, Sr, Zr, Ag, Cd, and Ta) were detected as well as their concentrations and correlations were determined for both particulate size fractions. Their correlation matrix result indicates that some of the trace elements detected could have common source origins or similar chemical properties. The results were similar to the levels observed in moderately polluted urban areas and there is need for source identification and apportionment using receptor models in future studies.     

一株高效异养硝化菌的分离、鉴定及其氨氮去除特性

以丁二酸钠为唯一C源,从垃圾渗滤液活性污泥中富集、分离及筛选出一株高效的异养硝化菌,通过形态观察、生理生化特征及16S rDNA序列分析,对分离菌株进行了鉴定,同时对其硝化功能和氨氮去除特性进行了研究.结果表明,分离到的异养硝化菌为假单胞菌属(Pseudomonas sp.),命名为XS76,其GenBank登录号为(JQ934897).该菌经过24h培养,有约60%的氨氮转化为胞内氮,35%左右的氨氮被去除,仅有少量硝酸盐氮的积累,没有羟胺和亚硝酸盐氮的积累.碳源、有机氮源、C/N比、温度等因素均对氨氮去除有较大的影响,在接种量为4%、丁二酸钠为碳源、硫酸铵为氮源、C/N 15、转速180~200r/min、pH 6~9及温度为34℃,氨氮负荷为420 mg/L时处理效果最佳, 96 h氨氮去除率可达99.20%.显示了高效的氨氮去除效果,具有潜在的实际废水应用价值.     

产表面活性剂降解石油菌株产物性质及降解性能研究

微生物是组成生态系统的重要成员,在污染物去除中发挥着重要作用,是生物修复中的主力,然而在石油污染修复过程中,石油烃的疏水性会限制微生物对石油的降解,但一些微生物的细胞代谢物即生物表面活性剂,它是微生物在一定条件下代谢分泌产生的具有一定表面活性,集亲水基和疏水基结构于一分子的两亲性化合物,可以促进油的乳化,提高油的分散程度,增大菌株和油珠的接触机会,促进对石油烃的吸收和降解。在实验室分离得到了7株产表面活性剂石油降解菌株,经分子鉴定可知菌1和菌2都为粘质沙雷氏菌Serratia marcescens,菌3为居植物柔武氏菌Raoultella planticola,菌4,菌6和菌7都为克雷伯氏菌Klebsiella variicola,菌5为蜡状芽孢杆菌Bacillus cereus。主要研究了它们的生长与表面活性剂物质分泌状况的关系,发现随着时间增加,OD值随之增大,表面张力呈现下降趋势;并对菌株产物进行提取和薄层层析,离子型分析和红外光谱分析,初步判断其产物均为阴离子糖脂类;通过pH,初始油质量浓度,接种量和盐度4个单因素的变化研究菌1粘质沙雷氏菌,菌3居植物柔武士菌,菌5蜡状芽孢杆菌和菌6克雷伯氏菌对石油类物质降解能力,发现菌3居植物柔武氏菌和菌5蜡状芽孢杆菌降解性能较好;通过响应曲面法优化蜡状芽孢杆菌的降解条件,得出其最佳降解条件为pH为5.02,油质量浓度为3 g·L-1,接种量为1199.98μL,盐度为0.5 g·L-1时,在此条件下,菌株对石油的降解率为66.94%。